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A model of adult and egg populations of Anticarsia gemmatalis Hubner (Lepidoptera: Noctuidae) in soybean

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Title:
A model of adult and egg populations of Anticarsia gemmatalis Hubner (Lepidoptera: Noctuidae) in soybean
Added title page title:
Anticarsia gemmatalis
Creator:
Gregory, Ben M., 1951-
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Language:
English
Physical Description:
xx, 298 leaves : ill. (some col.) ; 28 cm.

Subjects

Subjects / Keywords:
Adults ( jstor )
Caterpillars ( jstor )
Eggs ( jstor )
Female animals ( jstor )
Modeling ( jstor )
Moths ( jstor )
Observational research ( jstor )
Oviposition ( jstor )
Sample mean ( jstor )
Soybeans ( jstor )
Dissertations, Academic -- Entomology and Nematology -- UF
Entomology and Nematology thesis Ph. D
Soybean -- Diseases and pests ( lcsh )
Velvet-bean caterpillar ( lcsh )
Alachua County ( local )
Genre:
bibliography ( marcgt )
non-fiction ( marcgt )

Notes

Thesis:
Thesis (Ph. D.)--University of Florida, 1986.
Bibliography:
Bibliography: leaves 285-296.
General Note:
Typescript.
General Note:
Vita.
Statement of Responsibility:
by Ben Gregory, Jr.

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University of Florida
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A MODEL OF ADULT AND EGG POPULATIONS
OF Anticarsia gemmatalis Hubner (LEPIDOPTERA: NOCTUIDAE) IN SOYBEAN









By




BEN GREGORY, JR.


A DISSERTATION PRESENTED TO THE GRADUATE SCHOOL
OF THE UNIVERSITY OF FLORIDA IN
PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY



UNIVERSITY OF FLORIDA


1986





















































Copyright 1986 by

Ben Gregory, Jr.























To My Friends






























"Any glimpse into the life of an animal quickens our own and makes it so much
the larger and better ever way."


John Muir, 1880















ACKNOWLEDGEMENTS


The inadequacy of words will inhibit me from being able to express completely my feelings of gratitude for all of the help that I received during my Ph.D. program, particularly with regards to my major professor and friend, Carl Barfield. He constantly provided me with funds and equipment for my research and always had time to encourage my endeavors and listen to my ideas. I learned much about myself from working with Carl and I will always be indebted to him for the opportunities he provided me and for the scientific development I achieved under his aegis. I admire Carl for what he has achieved as a scientist and as a father and I will miss his sense of humor. I cannot write enough about him. Working with Jerry Stimac, a member of my committee, has been a very rewarding experience. His ecological insights and systems perspectives have deeply affected my development as a scientist. Jerry is a free thinker and an individual that loves to explore his environment. He also has an insatiable and wonderful penchant for a good laugh. Frank Slansky, another member of my committee, exhibits scientific standards that I would one day like to achieve. Frank is a remarkable scientist and I am indebted to him for his ecological insights into my experiments. He has a fantastic sense of humor and he never seems to miss a beat with it. He also has a wonderful family. Interacting with Ken Boote, the last member of my committee, has been very educational. His inquiries about my course work and research









progress were always helpful and encouraging. Ken's boundless energy and enthusiasm have been enjoyed and admired.

I owe special thanks to Don Herzog. Without his financial support and friendship my program would have been very difficult to complete, if not impossible. His constant support and encouragement over the years have always been appreciated. I envy anyone that has the opportunity to work and interact with Don.

I also owe special thanks to Strat Kerr for the tireless hours he spent coordinating my graduate activities and for financially supporting me during some rough times. He constantly went out of his way for me and liberally interpreted bureaucratic rules that made life a lot easier for me. The students in the department are lucky to have Strat's guidance, help and concern.

I would like to thank Norm Leppla for providing me with laboratoryreared velvetbean caterpillar larvae over the years. Our many discussions about science, life and women (not necessarily in that order) have been illuminating. Norm is a good friend.

Pat Greany has a wonderful personality and I am indebted to him for his photographic expertise. I learned a lot from Pat and I appreciate the many hours he took to help me with my research.

I thank Everett Mitchell for loaning me his blacklight traps.

Everett's field knowledge was invaluable for the success of my project and he always had time to listen to my ideas and to help me with their fruition.

I will miss the frequent discussions I had with Jon Allen. He

constantly stimulated my thoughts about quantitative ecology and taught me how to convert complex problems into easy problems that could be readily solved. His views about life have been illuminating.


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Discussions about personal and career goals with Dale Habeck, John Strayer, Don Hall, Jim Lloyd, and Dan Shankland were invaluable.

I thank Jim Jones for suggesting that I write my model with SAS and I am indebted to Ramon Littel, Ken Portier, Mark Yang, Victor Chew, Partha Lahiri, and Greg Pepples for their statistical expertise. I also owe thanks to Niklaus Hostettler and the legions of CIRCA consultants that helped me with my SAS programs.

I owe very special thanks to Anne Keene for typing my dissertation and for her enduring abilities to type both night and day. The completion of my dissertation would have been impossible without her assistance. She is a superb typist and frequently went out of her way to accommodate my schedule. She loves hard work and will not stop until the job is done. Anne has a real zest for life and is a very special person. The world needs more people like Anne.

Margie Niblack drew most of the figures in my dissertation, as well as my M.S. thesis. Working with her has always been fun. Margie is an excellent artist/illustrator, works very hard, and is seemingly tireless. Her willingness to help me with my graphics whenever possible will always be appreciated. I will miss her warm personality, sweetnaturedness and generous heart.

I would like to thank Laura Line Reep for drawing three of the

figures in my dissertation. Mary Crume of the Graduate School completed a mechanical critique of my dissertation. The time and effort she spent completing her excellent critique have been appreciated very much.

In far too many ways to mention, my work and life have been enriched by the friendship and help of Paul Wales, Kris Elvin, Bob O'Neil et al., Jane and Ken Cundiff, Debi Waters, Nancy Phillips, Carol


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Carlysle, Niki Altieri, Nell Backus, Niklaus Hostettler, Joe DeNicola, Arlene Arroya, Lois Wood, Nancy Osteen, Sanjoy Malik, Nancy Cohen, Carol Morris and Tasha, Sue Rutherford, John Knaub, Edilson Oliveira, Euripedes Meneze, Jorge Pena, Wade Bell, Eunice Smith, Gary Fritz, Doug Johnson, Mike Linker, John Luna, Vicki Ferguson, Bonnie Busick, Sherry Hickman, Leslie Daniels, Kirti Patel, Steve Hurst, Susan Jungreis, Rudiger Klein, Jackie Belwood, Howard Beck, Phil Callahan, Ngo Dong, Annie Yao, E. B. Whitty, Dennis Profant, Rick Reynolds, Bob Sullivan, Pamela A. Duelly (and plant #44), Edna Mitchell, Susan Braxton, Takuja Hayakawa, David Hall, Sheila Eldridge, Myrna Lynchfield, Barbara and Keith Hollien, Ralph Brown, Jack Rye, Richard Guy, Polly Teal, Sue Wineriter, Tommy Smith, T. J. Walker, Frank Mead, Marsha Stanton, G. B. Edwards, David W. Hall, Paul, Gene, Rudy, Anne, Weboon and Kent.

The completion of my dissertation would have been impossible

without the friendship of Gail Childs (and Meghan), Greg Wheeler (my drinking buddy), Larry (Skep) Smith, Mike Keller, Cherie Warlick and Barbara Muschlitz. Each of them has a very special place in my heart.

Also, the completion of my dissertation would have been impossible without the love of my family and their many sacrifices. I have frequently missed the love and companionship of Nancy, Ben Sr., Buddy, Barbara, Scott, Kathy, Caroline, Susan, Roy, Helen, and Ollie.


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TABLE OF CONTENTS


PAGE

ACKNOWLEDGEMENTS .................................................. V

LIST OF TABLES..................................................... xiii

LIST OF FIGURES.................................................... xvi

ABSTRACT.......................................................... xix

CHAPTERS

I INTRODUCTION........ ........................................ ... 1

II LITERATURE REVIEW............................................ 6

Introduction.................................................... 6

Soybean Ecology................................................. 6

General Description...................................... 7
Development and Growth...................................... 8
Water Stress.............................................. 13
Susceptibility to Insect Attack........................... 13

Velvetbean Caterpillar Ecology................................ 14

Distribution................................................ 14
Life Stages.............................................. 15
Life History............................................. .. 16
Adult Behavior.......................................... 16
Host Plants......................................... .... 17
Natural Enemies............................................. 23
Sampling and Economic Thresholds.......................... 23
Models................................................... 23
Velvetbean Caterpillar as a Soybean Pest................. 24

Velvetbean Caterpillar/Soybean Interactions.................. 25

III BEHAVIORAL ECOLOGY OF ADULT VELVETBEAN CATERPILLAR........... 28

Introduction.................................................. 28


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PAGE

Literature Review............................................. 29

General Activity.......................................... 29
Flight in the Laboratory................................. 29
Flight in the Field...................................... 30
Mating................................................... 32
Oviposition............................................... 34
Feeding.................................................... 37
Predators................................................ 38

Research Goals............................................... 38

Materials and Methods................. .............. ........ 39

Quantitative Technique.................................... 40
Assumptions............................................. 41

Results and Discussion........................................ 41

Flight Activity........................................... 43
Mating.................................................... 45
Oviposition............................................. 53
Feeding. ................................................. 61
Predators................................................ 74

Conclusions................................................. 77

IV MEASUREMENT AND ANALYSIS OF INTRAFIELD ACTIVITY
OF ADULT VELVETBEAN CATERPILLAR............................... 81

Introduction.................................................... 81

Materials and Methods......................................... 82

Adult Sampling ........................................... 82
Female Dissections....................................... 85
Physical Variables........................................ 85

Results and Discussions...................................... 88

Blacklight Trap.......................................... 88
Female Dissections......................................... 90
Adult Trap-Cage....................................... ... 95
Effect of Vapor Pressure Deficit........................ 99
Sex Ratio................................................... 102
Impact of Physical Variables ............................. 105
Calibration of Adult Density. ........................... 108

Conclusions................................................... 108










PAGE

V MEASUREMENT OF EGG DENSITY.................................... 113

Introduction.................................................. 113

Materials and Methods......................................... 114

Egg Development and Coloration. ........................... 114
Field Sampling of Velvetbean Caterpillar Eggs............ 115

Results and Discussion........................................ 116

Egg Development and Coloration. ........................... 116
Field Sampling of Velvetbean Caterpillar Eggs............ 122
Egg-Speckling Hypothesis.................................. 124

Conclusions................................................... 126

VI A MODEL OF VELVETBEAN CATERPILLAR ADULT
AND EGG POPULATIONS........................................... 127

Introduction.................................................. 127

Model Objective............................................... 128

Data Requirements for Model Construction
and Validation................................................ 128

Model Assumptions............................................ 130

Model Conceptualization....................................... 130

Model Structure................................................. 132

Function for Total Female Population..................... 133
Functions for Mated Female Population and Mortality...... 133 Functions for Oviposition................................. 134
Function for Total Egg Number............................ 136
Function for Predicted Egg Density....................... 136

Model Behavior............................................... 136

Simulation of 1982 Egg Population with a Constant
Ovipostional Rate........................................ 137

Simulation of 1982 Egg Population with a Variable
Ovipositional Rate....................................... 137

Simulation of 1981 Egg Population with a Variable
Ovipositional Rate........................................ 142

Conclusions................................................... 144


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PAGE

VII SUMMARY AND CONCLUSIONS........................................ 147

APPENDICES

A AGRONOMIC PRACTICES AND SOYBEAN PHENOLOGICAL-STAGES.......... 155

B IDENTIFICATION OF ADULT Anticarsia gemmatalis Hubner
and Mocis latipes Guenee...................................... 161

C BEHAVIORAL OBSERVATIONS: QUANTITATIVE TECHNIQUE AND DATA.... 168

D ADULT DENSITY AND PHYSICAL VARIABLE DATA, AND
MATHEMATICAL DESCRIPTIONS OF PHYSICAL VARIABLES.............. 203

E PICTORIAL KEY OF SOME LEPIDOPTERA EGGS FOUND ON SOYBEAN...... 237 F EGG DENSITY DATA.............................................. 273

G SAS PROGRAMS AND DATA FILES FOR MODEL OF ADULT AND
EGG POPULATIONS............................................... 276

LITERATURE CITED................................................... 285

BIOGRAPHICAL SKETCH................................................ 297


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LIST OF TABLES


PAGE


Table 1.1. Table 2.1. Table 2.2. Table 2.3. Table 2.4. Table 3.1. Table 3.2. Table 3.3. Table 3.4. Table 3.5.


Comparison of soybean yield and profit among various densities and timings of adult velvetbean caterpillar influx, as simulated with the Soybean Integrated Crop Management model. Soybean was not irrigated in any simulations.............................................. 4

Description of soybean vegetative stages.............. 9

Description of soybean reproductive-stages............ 10

Average and range of developmental time required for a soybean plant to develop between stages.................................................. 12

Reported host plants of larval velvetbean caterpillar............................................ 18

Amount of time dedicated to behavioral observation of adult velvetbean caterpillar in a 1 ha soybean field at the Green Acres Research Farm, Alachua County, FL, from 1980-82................ 42

Estimates of the absolute density of adult females of the velvetbean caterpillar in a soybean field. Density was determined with an adult trap-cage (see Chapter IV) in 1982 at the Green Acres Research Farm, Alachua County, FL............................................. 55

Mean total oviposition by adult females of the velvetbean caterpillar reared from eggs at constant temperatures, 14L:10D photoperiod, and RH > 80% .............................................. 58

Number of unsexed, male, and female adults of the velvetbean caterpillar observed feeding in a soybean field at Green Acres Research Farm, Alachua County, FL, in 1980-82......... 62

Observational records of feeding by adult velvetbean caterpillar during photophase at the Green Acres Research Farm, Alachua County, FL, from 1980-83....................................... 63


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PAGE


Table 3.6. Table 3.7. Table 3.8. Table 3.9. Table 4.1. Table 4.2.





Table 4.3. Table 4.4. Table 4.5.


Number of unsexed adults of the velvetbean caterpillar observed feeding in a soybean field at Green Acres Research Farm, Alachua County, FL, in 1980-82. Description of food site and host provided................................. 65

Number of male and female adults of the velvetbean caterpillar feeding in a soybean field at Green Acres Research Farm, Alachua County, FL, from 1980-82. Description of food site and host provided................................. 66

Number of adult males of the velvetbean caterpillar feeding in a soybean field at Green Acres Research Farm, Alachua County, FL, from 1980-82. Also, number of males per aggregate, number of aggregates, and description of food site are provided................. 67

Records of spider predation on adult velvetbean caterpillar (VBC) from 1980-83 at Green Acres Research Farm, Alachua County, FL, in a 1 ha soybean field. All records occurred during scotophase............................................ 75

Description of physical variables monitored in Alachua County, FL, in 1981-82..................... 86

Amount of rainfall recorded at the number 3 WSW climatological station of the University of Florida, Gainesville, FL, Alachua County. Cooperative climatological station of the Agronomy Department and NOAA.......................... 91

The mean number (SE) of spermatophores per female per reproductive category of adult velvetbean caterpillar. Females were caught in a blacklight trap during 1981 at the Green Acres Research Farm, Alachua County, FL............... 96

Mean seasonal sex ratios of adult velvetbean caterpillar caught in blacklight traps and an adult trap-cage in a 1 ha soybean field at the Green Acres Research Farm, Alachua County, FL ....********............................................ 104

Regression equations of physical variables and total numbers of males, females, and adults of the velvetbean caterpillar. Moths were caught in a blacklight trap at the Green Acres Research Farm, Alachua County, FL..................... 106


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PAGE


Table 4.6. Table 4.7. Table 4.8. Table 5.1. Table 5.2. Table 5.3. Table 6.1.


Regression equations of physical variables and weighted numbers of males, females, and adults of the velvetbean caterpillar. Moths were caught in a blacklight trap at the Green Acres Research Farm, Alachua County, FL..................... 107

Regression equations of total daily number of velvetbean caterpillar moths in the field and total nightly number of moths caught in the blacklight trap during 1982 at the Green Acres Research Farm, Alachua County, FL. Total number of moths (females, males, and total adults) were determined with adult trap-cage data.................. 109

Regression equations of total daily number of velvetbean caterpillar moths in the field and total nightly smoothed number of moths caught in the blacklight trap (BLT) during 1982 at the Green Acres Research Farm, Alachua County, FL. Total number of moths (females, males, and total adults) were determined with adult trap-cage data ...................... ............................ 110

Mean developmental time of speckled, brownish, and hatched velvetbean caterpillar eggs at two different temperatures. Colony (1982) and wild (1983) females were used in the study................. 119

Mean developmental time and rate (SE) for speckling to occur in VBC eggs from colony females at six different temperatures. Mean number of degree-hours required for speckling (thermal constant) was 153.27......................... 120

The total number of degree-hours accumulated between sunset (onset of oviposition) and plant sampling during each sample date in 1981 and 1982. Mean number of degree-hours required for speckling to occur in VBC eggs is 153.27.......... 123

Parametric values of ovipositional rate and SOY used in the oviposition function of the adult and egg population model of velvetbean caterpillar. Values are based on data collected in 1982 and model simulations..................................... 135


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LIST OF FIGURES


PAGE


Figure 3.1. Figure 3.2. Figure 3.3. Figure 3.4. Figure 3.5. Figure 3.6. Figure 3.7. Figure 3.8. Figure 3.9. Figure 4.1.




Figure 4.2.




Figure 4.3.


Mating pair of adult velvetbean caterpillar on a soybean leaflet ................................. 4E

The percent-normalized sample mean ( SE) of each post-sunset hour for activities of adult velvetbean caterpillars .............................. 52

Linear relationship between total eggs per velvetbean caterpillar adult female and temperature............................................. 59

Aggregation of velvetbean caterpillar males on an aerial net...................................... 68

Aggregation of velvetbean caterpillar males on the screen of an insectary........................ 69

Adult velvetbean caterpillar feeding at the surface of a bahiagrass raceme....................... 71

Adult velvetbean caterpillar feeding at the surface of a dead soybean leaflet.................... 72

Green lynx spider [Peucetia viridans (Hentz)] preying on an adult male velvetbean caterpillar...... 78

Orbweaver spider (Acanthepeira sp.) preying on an adult female velvetbean caterpillar............... 79

Trap-cage used to collect adult velvetbean caterpillar in a 1 ha soybean field during 1982 at the University of Florida's Green Acres Research Farm, Alachua County, FL.................... 84

Total number of velvetbean caterpillar moths captured in a blacklight trap per night in a
1 ha soybean field at the Green Acres Research Farm, Alachua County, FL............................. 89

Total number of adult velvetbean caterpillar females per reproductive category per night.......... 93


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PAGE


Figure 4.4. Figure 4.5. Figure 4.6. Figure 4.7. Figure 4.8. Figure 4.9. Figure 5.1. Figure 5.2. Figure 5.3. Figure 6.1. Figure 6.2. Figure 6.3.


Total number of velvetbean caterpillar unmated adult females per fat body content category per night ............................................

The mean number of spermatophores per adult velvetbean caterpillar female per week...............

Mean number ( 90% confidence interval) of velvetbean caterpillar moths captured per sample (21.16 m2) with the adult trap-cage...........

Vapor pressure deficit (VPD) in a 1 ha soybean field in 1981 at the Green Acres Research Farm, Alachua County, FL....................

Vapor pressure deficit (VPD) in a 1 ha soybean field in 1982 at the Green Acres Research Farm, Alachua County, FL....................

Sex ratio of velvetbean caterpillar adults caught in blacklight traps (BLT) and an adult trap-cage (ATC) in a 1 ha soybean field at the Green Acres Research Farm, Alachua County, FL........

Eggs of the velvetbean caterpillar...................

Developmental rate of speckling in VBC eggs at six different temperatures........................

Mean densities per .91 m-row ( 95% confidence interval) of freshly-laid VBC eggs on soybean at the Green Acres Research Farm, Alachua County, FL ...........................................

Flow diagram of a model of VBC adult and egg populations in a soybean field.......................


94 97 98 100 101




103 117 121 125 131


Mean velvetbean caterpillar egg density per .91 m-row of soybean during 1982 in a 1 ha field at the Green Acres Research Farm, Alachua County, FL. Ovipositional rate was a constant during the simulation................................. 138

Mean velvetbean caterpillar egg density per .91 m-row of soybean during 1982 in a 1 ha field at the Green Acres Research Farm, Alachua County, FL. Ovipostional rate was variable during the simulation ........... .................... 140


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PAGE


Figure 6.4. Mean velvetbean caterpillar egg density per
.91 m-row of soybean during 1981 in a 1 ha
field at the Green Acres Research Farm, Alachua
County, FL. Ovipositional rate was variable
during the simulation................................ 143


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Abstract of Dissertation Presented to the Graduate School of the University of Florida in Partial Fulfillment of the
Requirements for the Degree of Doctor of Philosophy



A MODEL OF ADULT AND EGG POPULATIONS OF Anticarsia gemmatalis Hubner (LEPIDOPTERA: NOCTUIDAE) IN SOYBEAN By

BEN GREGORY, JR.

May, 1986


Chairman: C. S. Barfield
Major Department: Department of Entomology and Nematology


A model of adult and egg populations of the velvetbean caterpillar (A. gemmatalis) was constructed and validated. The model mimicked velvetbean caterpillar (VBC) egg densities in a soybean field within 95% confidence intervals of estimated means. Model construction was based on data from nine separate experiments (1980-84) that allowed for an understanding or quantification of the following: adult moth identification, adult behavior in the field, relative and absolute estimates of adult density, female reproductive states, egg identification, egg developmental rates, absolute estimates of egg density, and the impact of various environmental variables on adult and egg dynamics.

Adult density estimates were obtained with a blacklight trap and an unique adult trap-cage. These density estimates were calibrated with a linear regression equation that was used in the model structure to


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predict the number of ovipositing females in the field. The capture of adults in the blacklight trap (BLT) coincided with the appearance of eggs in the field, while adult residency in the field appeared to be delayed until an appropriate vapor pressure deficit had been reached in the field. Dissections of adult females revealed that most females were mated and contained large amounts of fat body. Select physical variables were explored with multiple linear regression for their effect on blacklight trap catch but no consistently adequate correlations were uncovered.

Velvetbean caterpillar eggs were shown to be polychromatic during development. These color changes were temperature-dependent and were used to age field collected eggs. Egg densities predicted by the model were more accurate with a variable ovipositional rate as opposed to a constant rate. The variable ovipositional rate was linked to changes in soybean phenology. In model validation, 65% of the model's predicted values fell within 95% confidence intervals of field estimates. Differences between predicted and estimated values were attributed to unpredictable fluctuations in BLT catch and to variation in ovipositional rate between years.


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CHAPTER I
INTRODUCTION


Soybean, Glycine max (L.) Merrill, is presently the most important grain legume in the world and is used for food, medicine, and oil (Weiss 1983). Farmers in the United States produce ca. 56% of the world's soybean or ca. 43 million metric tons (FAO 1984). Thirty-seven percent of the soybean production in the United States occurs in the southeast, and this percentage is expected to increase considerably by the year 2000 because of an increasing worldwide demand (Turnipseed et al. 1979). Soybean production in the southeastern United States is plagued by numerous pest problems (e.g., insects, weeds, nematodes, and plant pathogens), and these problems are expected to escalate because of the increasing acreage being devoted to this crop (Turnipseed et al. 1979).

One way to explore alternative strategies for the management of

soybean pests is through the utilization of crop/pest models, where the models are mathematical representations (computer simulated) of the interactions between the crop and its principal pest-species (Stimac and O'Neil 1985). Crop/pest models can be used "to simulate the dynamics of a crop and pests in a single field so that decisions can be made regarding pest management and other production practices for that field. The objective of building a crop/pest model is to describe the dynamics of the crop and pests in the context of the environment in which they coexist. The environment includes many factors influencing the growth of the crop and pest populations: weather inputs, such as temperature,


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rainfall and solar radiation; biological inputs, such as natural enemies of the pests; and production system inputs, such as irrigation, cultivation, and application of pesticides" (Stimac and O'Neil 1985, pp. 323-324). These factors must be quantified and mathematically described in submodels of the crop, pests, and production tactics.

One of the objectives of a multi-university investigation* was to construct a soybean crop model that could be used to evaluate soybean production strategies under various combinations of stresses (e.g., water or pests). To accomplish this objective, the Soybean Integrated Crop Management (SICM) model was constructed. This model is composed of an aggregate of submodels coupled to a physiologically-based plantgrowth model of soybean, and is designed to allow the user to study various management strategies at the field level for different weather, cultural, soil, pathogen, weed, and insect scenarios (Wilkerson et al. 1982, 1983).

One of the SICM submodels represents the population dynamics of

velvetbean caterpillar (VBC), Anticarsia gemmatalis Hubner (Lepidoptera: Noctuidae), a major defoliating pest of soybean (Herzog and Todd 1980, Wilkerson et al. in press). In the current version of the VBC submodel, immigration of VBC adults into soybean has been difficult to assess because no data of adult or egg density are available (see Wilkerson et al. 1982). Data on adult density are essential for model initialization, as VBC life stages do not overwinter in soybean and infestation depends on the annual immigration of adults into soybean



*Investigation entitled The Development of Comprehensive, Unified, Economically, and Environmentally Sound Systems of Integrated Pest Management--funded by the Environmental Protection Agency and the United States Department of Agriculture.






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fields (see Herzog and Todd 1980, Wilkerson et al. 1983). Furthermore, egg density data are essential for model construction because the mere presence of adults does not connote the presence of eggs and the resultant defoliating larvae. The absence of VBC immigration data is not surprising because the control recommendations for most pests are designed without consideration for quantitative estimates of pest immigration (see Barfield and O'Neil 1984).

To assess immigration in the current version of the VBC Submodel, adult and egg densities were estimated from larval densities (Stimac,* personal communication). Changes in the density and timing of adult influx resulted in notable differences in soybean yield and grower profit (see Table 1.1). With density varied and timing of influx held constant, profit per hectare varied from $169.21 (low density) to

-$214.26 (high density). With influx timing varied and density held constant, profit per hectare varied from $178.43 (late influx) to

-$289.63 (early influx). Without VBC (i.e., a simulation control), profit per hectare was $241.61, the highest of all the simulations. Clearly, the need to investigate VBC immigration into soybean was delineated through the use of these simulations.

Present research goals were to (1) investigate the immigration of VBC adults into soybean, (2) explore the interactions between soybean phenology and VBC adults, and (3) quantify adult and egg densities in soybean. These goals were accomplished by the construction of an adult



*J. L. Stimac, Associate Professor, Department of Entomology and Nematology, University of Florida, Gainesville, FL 32611. Larval densities at time "t" were used to determine egg and adult densities at time "t-1" by calculating the densities of adults and eggs required to produce the known larval densities. Mortality values of adults and eggs were used in these calculations.






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Table 1.1.


Comparison of soybean yield and profit among various densities and timings of adult velvetbean caterpillar influx, as simulated with the Soybean Integrated Crop Management model (modified from Wilkerson et al. 1982). Soybean was not irrigated in any simulations.


VBCa Influxb Yield Profit Density Timing (Kg/ha) ($/ha)


Low Normal 1896.18 169.21 Average Normal 1493.02 65.70 High Normal 403.97 -214.26 Average Early 110.32 -289.63 Average Normal 1493.02 65.70 Average Late 1931.86 178.43 None None 2177.57 241.61


a
High = +0.5 Average; bEarly was 30 days prior than normal.


Low = -0.5 Average.


to normal and late was 30 days later






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and egg population model. The objective of this model is to mimic the number of eggs laid by VBC adults in a 1 ha soybean field. To accomplish this objective, experiments were conducted to understand or quantify (1) egg identification, (2) egg developmental rates, (3) estimates of the absolute density of eggs, (4) adult identification, (5) observations of adult behavior in the field, (6) estimates of the relative and absolute densities of adults, (7) categories of female reproductive states, and (8) the impact of various environmental variables (e.g., temperature) on adult and egg dynamics. Experimental methods, results, and discussions are presented in the chapters and appendices that follow.

Chapter II is a general review of soybean ecology, VBC ecology, and VBC/soybean interactions. Chapter III is a study on the field behavior of adult VBC. Chapter IV is a study on sampling for adults, of the relationships between adult density and selected environmental variables, and of the determination of female reproductive categories. In Chapter V, an egg sampling technique and egg density data are presented. In Chapter VI, a model of VBC adult and egg populations is presented, and Chapter VII contains the summary and conclusions.















CHAPTER II
LITERATURE REVIEW


Introduction

Accomplishment of present objectives (see Chapter I) demanded that soybean, velvetbean caterpillar (VBC), and the environment of both be viewed as interacting components of a system. Velvetbean caterpillar use soybean as an adult ovipositional substrate (see Greene et al. 1973), a larval food source (see Moscardi et al. 1981a), and an adult habitat (see Herzog and Todd 1980). Soybean foliage and yield decrease with VBC larval consumption (Strayer 1973), and temperature affects the growth of both species (see Parker and Borthwick 1943, Johnson et al. 1983). Obviously, to view soybean and VBC as components of a system requires an understanding of the ecology of each species. The objective of this chapter is to review briefly the ecology of soybean and VBC, their relevant interactions, and environmental factors that affect both.

Soybean Ecology

Soybean, Glycine max (L.) Merrill, became a domesticated species probably in the North China Plains around the 11th century (Hymowitz 1970). The progenitor species apparently was G. ussuriensis Regel and Maack (Morse et al. 1949). Polhill and Raven (1981) provide part of the hierarchical classification for soybean as follows: Order: Rosales

Family: Leguminosae

Subfamily: Papilionoidae


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Tribe: Phaseoleae

Subtribe: Glycininae

Introduced into the United States as early as 1804, this legume did not become an important crop in this country until about 1890 (Morse 1927). Soybean currently is distributed worldwide (Weiss 1983). General Description

Soybean is a summer annual, usually bushy and upright, and 30-122 cm in height (McGregor 1976, Weiss 1983). The main stem has 14-26 nodes; however, the first 2 nodes actually are composed of 2 opposite nodes. Two cotyledons are borne at the first node, whereas the second node bears two primary leaves. All other nodes on the main and lateral stems bear alternate and pinnate trifoliolates on long petioles; however, some multi-foliolate lines do occur (Shibles et al. 1975). Pubescence occurs on most of the above-ground plant surface and may act as a resistance mechanism to insect oviposition or feeding (see Kobayashi and Tamura 1939, Nishijima 1960, Kogan 1975, Turnipseed 1977, Oliveira 1981).

"The root system is extensive, with a tap-root which may exceed 1.5 m in length, giving rise to many lateral branches usually in the 0-30 cm horizon. However, there is considerable variation between cultivars in respect of rate of growth, total amount, spread and degree of penetration of roots. Roots initially elongate faster than above-ground growth, and in the field under normal conditions, roots of rain-growth plants will be twice as long as above-ground plant height at the six-node stage" (Weiss 1983, p. 344). Root nodules occur due to symbiosis with a nitrogen fixing bacterium, Bradyrhizobium japonicum






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(Buchanan 1980) comb. nov.* (see Weiss 1983). From a study on the partitioning of C14 photosynthate in soybean, Housely et al. (1979) speculate that less carbon is channeled into amino acids of nodulated plants, as opposed to non-nodulated plants. The significance of this channeling is unclear, but perhaps nodulated soybean can channel more carbon into seed formation and plant defense. Development and Growth

Fehr and Caviness (1977) describe and illustrate the stages of

soybean development based on vegetative and reproductive states (Tables

2.1 and 2.2). Soybean is a short-day plant, and reproduction (or flowering) is triggered by photoperiod (Garner and Allard 1930). Temperature and variety can be important in determining the beginning of flowering (van Schaik and Probst 1958, Fehr and Caviness 1977). Flowering occurs over a four to six-week period (Shibles et al. 1975). Flowers are self-pollinated (Shibles et al. 1975, McGregor 1976), but Erickson (1975) demonstrated a significant yield increase in two varieties due to honey-bee, Apis mellifera L., pollination. Soybean flowers do produce nectar (Jaycox 1970) and possess most, if not all, of the anatomical adaptations of entomophilious plants (e.g., the nectar guide)(Erickson and Garment 1979).

Soybean exhibits two types of growth habit, determinate and indeterminate. Canopies of these two growth types are distinctly different. The largest leaves of indeterminates occur at the center of the plant, with gradations in size toward each end of the stem. With determinate cultivars, all mature leaves above the middle of the plant



*Synonym is Rhizobium japonicum Buchanan (Jordon 1982).






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Table 2.1.


Description of soybean vegetative stages (Fehr and Caviness 1977).


Stage Stage Title Description


VE Emergence Cotyledons above the soil surface. VC Cotyledon Unifoliolate leaves unrolled sufficiently so that leaf edges are not touching. Vi First-Node Fully developed leaves at unifoliolate nodes. V2 Second-Node Fully developed trifoliolate leaf at node above the unifoliolate nodes.

V3 Third-Node Three nodes on the main stem with fully developed leaves beginning with the unifoliolate nodes.

V(n) nth-Node The number of nodes on the main stem is equal to 'n', beginning with the unifoliate nodes.






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Table 2.2.


Description of soybean reproductive-stages (Fehr and Caviness 1977).


Stage Stage Title Description


R1 Beginning Bloom R2 Full Bloom R3 Beginning Pod R4 Full Pod R5 Beginning Seed R6 Full Seed R7 Beginning Maturity R8 Full Maturity


One open flower at any node on the main stem.

Open flower at one of the two uppermost nodes on the main stem with a fully developed leaf.

Pod 5 mm long at one of the four uppermost nodes on the main stem with a fully developed leaf.

Pod 2 cm long at one of the four uppermost nodes on the main stem with a fully developed leaf.

Seed 3 mm long in a pod at one of the four uppermost nodes on the main stem with a fully developed leaf.

Pod containing a green seed that fills the pod cavity at one of the four uppermost nodes on the main stem with a fully developed leaf.

One normal pod on the main stem that has reached its mature pod color. Mature pod color varies with variety.

Ninety-five percent of the pods that have reached their mature pod color. Five to ten days of drying weather are required after R8 before the soybeans have less than 15% moisture, and can be harvested.






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are approximately the same size, and their resultant canopies are thought to have poorer light-distribution characteristics. Indeterminate cultivars continue to grow vegetatively during flowering, and early pod, and seed development. Flowering begins when these cultivars have reached about half their height and continues as the plant grows taller. For determinate varieties, plants reach full height at flowering and flowers emerge at approximately the same time from all nodes (Fehr et al. 1971, Shibles et al. 1975, Fehr and Caviness 1977).

Fehr and Caviness (1977) provide average and range estimates of

soybean development between stages (see Table 2.3). The average number of days for complete development is 125, with a range of 74 to 218. The large range in developmental time results from effects of temperature, variety, photoperiod, and water stress (Doss et al. 1974, Fehr and Caviness 1977). The major factor that influences vegetative growth is temperature. Seedling emergence and leaf development are retarded by low temperatures and enhanced by high temperatures (Fehr and Caviness 1977).

Soybean leaves exhibit Calvin-cycle photosynthesis, but stems and pods also contribute to carbon dioxide uptake (Weiss 1983). Leaf area production begins slowly, then increases rapidly and increases almost linearly during mid-vegetative growth. Maximum leaf-area index (LAI*) values of five to eight can be achieved by late flowering. During seed filling and after flowering, LAI declines progressively by abscission of lower leaves (Shibles et al. 1975).





*Leaf Area Index (LAI) is "the surface area of leaves per unit surface area of ground" (Lewis 1977, p. 87).






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Table 2.3.


Average and range of developmental time required for a soybean plant to develop between stages (Fehr and Caviness 1977).


Averagea Range inb Developmental Time Developmental Time Stage (day) (day)


0c VE VE VC VC VI Vl V2 V2 V3 V3 V4 V4 V5 V5 V6 R1 R2 R2 R3 R3 R4 R4 R5 R5 R6 R6 R7 R7 R8


5 15 3 10 3 10 3 10

3 8 3-8 3-8 2-5 0- 7 5 15 5- 15 4 26 11 20 9 30

7 18


d 3 0,3


aAverage total developmental time is 125 days. bRange varies from 74 to 218 days. C0 = planting

dRI and R2 generally occur simultaneously in determinate varieties. The time interval between R1 and R2 for indeterminate varieties is about three days.






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Water Stress

"Soybeans use a lot of water" (Shibles et al. 1975, p. 159). With sufficient water, total water use from beginning bloom to maturity is nearly the equivalent of 95% open-pan evaporation (Peters and Johnson 1960). Water consumption by soybean is determined substantially by leaf area until full ground-cover is achieved. After full ground-cover, evaporative demand is the most influential variable. Leaf area distribution and water supply also affect water consumption. Soybean is water-stressed easily and may be under water stress more frequently and severely than many other plants. Water stress is caused by soil water deficit or high evaporative demand. Even on wet soils, plants can exhibit wilting under high evaporative demand (Shibles et al. 1975). Susceptibility to Insect Attack

Soybean is susceptible and sensitive to insect attacks for at least three reasons: (1) It is grown in monoculture in large acreages-approximately 25 million hectares were harvested in the United States in 1983 (see FAO 1984). The "plant apparency" of soybean, due to this acreage, makes it potentially highly vulnerable to insect herbivory (see Feeny 1975). (2) As part of a simplified agroecosystem with highenergy input, soybean, like other crops of the Green Revolution,* is highly susceptible to insect attack (see Perelman 1977, Altieri 1983).

(3) Soybean may have inadequate defenses against many insects, as man has introduced soybean into the range of these insects. For example, VBC apparently evolved in the Neotropical region (see Buschman et al. 1977) while soybean evolved elsewhere (see Weiss 1983).



*The Green Revolution is an attempt to solve crop production problems through the development of high-yielding varieties that require high inputs of pesticides, fertilizers, irrigation, and machinery.






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Velvetbean Caterpillar Ecology

Anticarsia gemmatalis Hubner was described by Hubner (1816, cited by Ford et al. 1975). Kimball (1965) and Borror et al. (1981) provide part of the hierarchial classification for this insect as follows: Order: Lepidoptera

Suborder: Ditrysia

Superfamily: Noctuoidea

Family: Noctuidae

Subfamily: Erebiinae.

Seven synonyms for A. gemmatalis are listed by Schaus (1940). The common name for A. gemmatalis, as accepted by the Entomological Society of America, is the velvetbean caterpillar (Sutherland 1978). Severe defoliation of velvetbean (Stizolobium deeringianum Bort.) by this insect in the early 1900's resulted in its common name (Chittenden 1905, Watson 1916a).

Distribution

The VBC is a tropical to subtropical species of the Western

Hemisphere (Ford et al. 1975) and ranges over much of North and South America, and all of Central America and the West Indies. In North America, the northern limits of the range are slightly above the 450N parallel, extending into Ontario and Quebec, Canada. In South America, the southern limit of the range appears to be approximately the 350S parallel, extending to Buenos Aires, Argentina (Ford et al. 1975, Herzog and Todd 1980).

The range of VBC in North America fluctuates temporally due to (1) suspected migration of adults (Watson 1916a), (2) winter mortality of immature stages (Buschman et al. 1981a), and (3) lack of occurrence of immature stages (Ellisor 1942, Buschman et al. 1977, Waddill et al.






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1982). Evidence to support migration is either speculative (see Watson 1916a) or indirect (Baust et al. 1981, Buschman et al. 1981a). No intensive studies of adult distribution in the winter exist, nor have direct-evidence studies (e.g., capture, mark, release, recapture) of adult migration been made. The 280N parallel has been indicated as the northern limit for winter distribution (Buschman et al. 1977), but some reports appear to conflict with this limit. A number of adults were caught in Gainesville, FL, following a freeze that occurred on 21 November 1914 (Watson 1915). Adults were caught again in Gainesville on 29 January 1916 (Watson 1916a) and on 4 March 1932 (Watson 1932) at the 29038'N parallel, 188 km above the 280N parallel. Life Stages

A description of VBC life stages is given by Watson (1916a) as egg, six larval instars, pupa, and adult. The egg is nearly 2 mm in diameter, less than 2 mm in height, prominently ribbed, and flattened on its lower surface (Watson 1916a). Egg coloration varies greatly: white, delicate pink, pale green, cryptic green, orange, reddish brown, transparent, slightly green, and green with red marks (see Watson 1916a, Douglas 1930, Hinds 1930, Ellisor 1942, Greene et al. 1973, Gutierrez and Pulido 1978). Larvae vary greatly in color and markings, particularly after the second instar. Longitudinal lines are usually black, white, yellow, or pink. Background color varies from light yellowish-green to mahogany brown. Length of a sixth instar larva varies from 38 to 48 mm (Watson 1916a).

Pupae are light green for approximately 24 hours, then turn brown. Pupation occurs usually at or below soil surface and in a loose, frail, earthen cell (Watson 1916a, Hinds 1930). Dorsal wing coloration of the adults is highly variable, with color ranging from ashen gray to light






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yellowish-brown to reddish brown (Watson 1916a, Kimball 1965, Leppla et al. 1977). Ventral coloration is more consistent, a cinnamon brown with a submarginal row of white spots (Watson 1916a). Sexual dimorphism of adult leg scales allows for accurate and rapid sexual identification. Males have tufts of long setae that are present on the femora of prothoracic legs and the tibiae of metathoracic legs. These long setae are absent on female legs (Anonymous 1974). Life History

The life history of VBC in the field is discussed by Watson

(1916a), Douglas (1930), Hinds (1930), Hinds and Osterberger (1931), Ellisor (1942), Buschman et al. (1977), Gutierrez and Pulido (1978), and Buschman et al. (1981a). Leppla (1976) and Leppla et al. (1977) report the life history under laboratory conditions. Larval development and consumption on different phenological stages of soybean are reported by Reid (1975), Moscardi et al. (1981a), and Olivera (1981). Nickle (1976) gives larval consumption rates on peanut leaves. Moscardi et al. (1981b) and Olivera (1981) report the effect of different soybean phenological stages on VBC oviposition, egg hatch, and adult longevity. Finally, Moscardi et al. (1981c) demonstrate the effects of temperature on oviposition, egg hatch, and adult longevity, and Johnson et al. (1983) present a temperature-dependent developmental model of VBC. Adult Behavior

Field and laboratory studies have been conducted on adult behavior. In general, the field studies have been qualitative, with little quantification of data. The reverse exists for the laboratory studies. Observations of adults with regard to oviposition, mating, feeding, and flight activity are reported by Watson (1916a), Douglas (1930), Hinds (1930), Greene et al. (1973), and Ferreira and Panizzi (1978). Greene





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et al. (1973) present the most detailed observations, but their data were collected over a short, seven-day time period. Johnson et al. (1981) report a behavioral study on the response of VBC to its pheromone. Heath et al. (1983) elucidate the chemical composition of VBC pheromone and the pheromonal effect on male and female behavior. Leppla (1976) and Leppla et al. (1979) indicate the circadian rhythms of locomotion and reproductive behavior of adults in the laboratory. Wales et al. (1985) demonstrate the flight and ovipositional dynamics of adult females during tethered flight.

Host Plants

At least 40 legumes and five non-legumes appear to serve as host plants for larvae of the VBC (Table 2.4). The authenticity of many of the records in Table 2.4 is questionable because they were not accompanied with (1) host scientific name, (2) confirmation of oviposition, (3) verification of complete larval development, (4) verification of larval and host identities, and (5) multiple sightings. Based on these records VBC probably is restricted to leguminous host plants and is therefore either monophagous (see Krieger et al. 1971) or oligophagous (see Slansky 1976).

Velvetbean caterpillars appear to have a marked preference for

soybean over other hosts. Douglas (1930) states that neither larvae nor feeding damage was sighted, except on soybean, in fields planted with soybean and the following crops: cotton,* kudzu, cowpea, and velvetbean. Hinds and Osterberger (1931) note a similar preference for soybean grown with velvetbean, cowpea, and other legume crops (names



*Some larvae crawled from completely defoliated soybean to cotton and fed on the cotton. Complete larval-development on the cotton was not assessed.










Table 2.4. Reported host plantsa of larval velvetbean caterpillar (modified from Moscardi 1979, Herzog
and Todd 1980).




Family Scientific Name Common Name Reference


Aeschynomenes sp. Agati grandiflora (L.) Desv. Arachis hypogaea L. Cajanus cajans (L.) Millsp. Cajanus indicus Spreng Canavalia gladiata (Say.)


Canavalia maritima Aub. Canavalia rosea Sw. Canavalia sp. Cassia fasciculata Michx. Cassia obtusifolia L. Desmodium floridanum Chapm.


Joint Vetch Gallito Trees Peanut Pigeon Pea Pigeon Pea Sword Bean de Cond. Horse Bean Canavalia




Partridge Pea Coffeeweed Beggar Lice


DPIb

Wolcott (1936) Anonymous (1928) McCord (1974) DPIb

Ellisor (1942)


Buschman et al. (1977) Tietz (1972) Watson (1916a), Ellisor (1942), Tietz (1972) Herzog (unpublished)c Buschman et al. (1977) Buschman et al. (1977)


Leguminosae









Table 2.4 (continued)


Family Scientific Name Common Name Reference


Leguminosae


Dolichos lablab L. Galactia spiciformis Glycine max (L.) Merrill Indigofera hirsuta L. Lespedeza sp. Medicago sativa L. Melilotus alba Desr. in Lam. Pachyrhizus erosus (L.) Urban Phaseolus calcaratus Roxb. Phaseolus lathyroides L. Phaseolus limensis Macf.
e
Phaseolus max Phaseolus semierectuse Phaseolus speciosus H.B.K.


Hyacinth Bean Galactia Torr. and Gray Soybean Hairy Indigo



Alfalfa White Sweet Clover Yam Bean Frijolito Rojo Wild Bean Lima Bean





Sweet Pea Vine


Buschman et al. (1977) Buschman et al. (1977) Nickels (1926) Buschman et al. (1977) USDA (1954a) Ellisor and Graham (1937) Waddill (1981) Buschman et al. (1977) Gutierrez and Pulido (1978) Buschman et al. (1977) Ford et al. (1975) Wolcott (1936) Tietz (1972) Buschman et al. (1977)











Table 2.4 (continued)


Family Scientific Name Common Name Reference


Phaseolus vulgaris var.


Pisum sativum L. Pisum sp.

Pueraria lobata Willd. Pueraria phaseoloides (Roxb)


Pueraria thumbergiana
(Siebold and Zucc.) Benth Rhynchosia minima L. Robinia pseudoacacia L. Sesbania emerus (Aubl.)
Britton and Wilson

Sesbania exaltata (Raf.)
V.L. Cory

Sesbania macrocarpa Muhlenb.
ex Raf.


Bush Bean humilis Alef. English Pea Field Pea Kudzu Tropical Kudzu Benth Kudzu Vine


Least Rhynchosia Black Locust Long Pod


Sesbania


Coffee Weed


Ford et al. (1975)


DPIb

DPIb

Buschman et al. (1977) Ford et al. (1975) Watson (1916a) Buschman et al. (1977) Ellisor (1942) DPIb


Tietz (1972)


Hinds and Osterberger (1931)


Leguminosae












Table 2.4 (continued)



Family Scientific Name Common Name Reference


Leguminosae










Begoniaceae Gramineae Malvaceae


Stizolobium deeringianum Bort. Tephrosia sp. Vigna luteola Jacq. Vigna repens (L.) Kuntze Vigna sinensis (L.) Endl. Begonia sp. Oryza sativa L. Triticum sp. Gossypium herbaceum L. Hibiscus esculentus L.


Velvetbean



Vigna Cowpea Cowpea Begonia Rice Wheat Cotton Okra


Chittenden (1905) USDA (1954b) Buschman et al. (1977) DPIb

Hinds and Osterberger (1931) DPIb

Tarrago et al. (1977) Wille (1939) Douglas (1930) Todd (unpublished)d









Table 2.4 (continued)



aThe authenticity of many of these records is questionable because they were not accompanied with (1) host scientific name, (2) confirmation of oviposition, (3) verification of complete larval development,
(4) verification of larval and host identities, and (5) multiple sightings. bHost records on file at Florida Department of Agriculture and Consumer Services, Division of Plant Industry (DPI), Gainesville, FL 32611. cD. C. Herzog, Professor, Entomology and Nematology Department, University of Florida, Agriculture and Education Center, Quincy, FL 32351.
dJ. W. Todd, Assoc. Professor, Department of Entomology, University of Georgia, Georgia Coastal Plain Experiment Station, Tifton, GA 31794.
eAuthor unknown.






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not provided). Ellisor and Graham (1937, p. 278) state that "moths select soybeans in preference to velvet beans for oviposition, even when the two crops are grown in adjacent fields." Ellisor (1942) reports soybean is preferred to alfalfa, cowpea, peanut, and velvetbean. Oddly, no studies of VBC and its hosts, except for soybean (see Moscardi et al. 1981a, 1981b) and peanut (see Nickle 1976), have been conducted to assess complete larval development, and adult eclosion. Natural Enemies

An extensive review and discussion of the parasitoids, predators, and pathogens of VBC is provided by Moscardi (1979). Two striking generalizations about VBC natural enemies that emerge from a synthesis of Moscardi's review are (1) the predators and parasites are generalists and (2) the pathogens are highly specific. O'Neil (1984) reports that predators are unable to control VBC populations because the predators are generalists and do not search sufficient leaf area. At the present time, pathogens appear to be the best natural enemy for controlling VBC populations (see Kish and Allen 1978). Sampling and Economic Thresholds

Sequential sampling and economic thresholds for management of VBC larvae in soybean are presented by Strayer (1973). Estimates of the relative and absolute densities of larvae in soybean are presented by Luna (1979). Linker (1980) provides sampling procedures for larvae in peanuts and soybeans, and presents an analysis of seasonal abundance. Techniques and methodologies for sampling of all VBC stages are reviewed and discussed by Herzog and Todd (1980). Models

At least six models of VBC dynamics in soybean are reported. Menke (1973) and Menke and Greene (1976) present a stochastic simulation model






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in which VBC dynamics and soybean defoliation are examined. Kish and Allen (1978) present a model predicting the incidence of Nomuraea rileyi (Farlow) Samson on VBC larvae. Luna (1979) reports an economic threshold model for chemical control of VBC larvae on soybean. O'Neil (1984) presents a model of predation on larvae. Predator and VBC densities, soybean leaf-area, and predator searching-behavior are incorporated into O'Neil's model. The Soybean Integrated Crop Management (SICM) model is a soybean plant-growth model that is coupled to multiple stress submodels (e.g., an insect-pest submodel). One of these submodels represents the population dynamics of the velvetbean caterpillar (Wilkerson et al. 1983). Wilkerson et al. (in press) present a temperature dependent VBC dynamics model. Velvetbean Caterpillar as a Soybean Pest

Velvetbean caterpillars are a chronic and primary pest of soybean for many reasons. Adults are highly mobile, exhibit early reproduction, and have a very high reproductive rate, while larvae develop rapidly and exhibit high survival. In short, VBC appears to be an r-strategist* (see MacArthur and Wilson 1967). Adults are caught as far north as Canada (Watson 1916a) and on oil-rig platforms in the Gulf of Mexico (Baust et al. 1981). Further, adults exhibit a low wing-loading ratio** that may require little energy for flight and may be an adaptation for flying long distances in search of host plants (Angelo and Slansky 1984); larvae utilize host plants that are widely dispersed and



*The crucial evidence needed for r- and K-selection is whether an organism allocates a greater proportion of its resources to
reproductive activities (r-strategist) than another related organism
(K-strategist) under any and all density-dependent and
density-independent mortality conditions.

**Wing loading ratio is body weight/wing area.






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ephemeral (see Herzog and Todd 1980), so adults must be able to fly between hosts. Mated females exhibit early reproduction, laying 50% of their eggs within four to nine days after emergence, and with oviposition steadily declining thereafter (Moscardi et al. 1981c). Total mean oviposition, for females reared as larvae on soybean, can be as high as ca. 963 eggs/female, with an extremely high net reproductive rate of ca. 365 (Moscardi et al. 1981b). In conjunction with this high reproductive rate, the mean developmental time from egg hatch to adult eclosion is ca. 22 days (Moscardi et al. 1981a). Finally, immature VBC stages exhibit high survival, except for larval mortality during late soybean growth from the pathogen, N. rileyi (Kish and Allen 1978, Elvin 1983, O'Neil 1984).

Velvetbean Caterpillar/Soybean Interactions

The VBC is believed to overwinter in southern Florida, the West Indies, Central America, and much of South America. This pest is hypothesized to migrate each year from overwintering areas into the southern United States (Watson 1916a, Herzog and Todd 1980, Buschman et al. 1981a). The temporal occurrence of immigration is unknown, as no direct evidence exists (Buschman et al. 1981a), but moths invade soybean fields in northern Florida from May to July (Greene 1976). Following colonization, larvae reach peak densities in August or September, or occasionally in early October (see Greene 1976, Linker 1980). As soybean senesces, usually in mid to late October, larval populations decline rapidly and VBC adults move to different hosts, both cultivated and wild (Ellisor 1942, Greene 1976, and Buschman et al. 1981a). Larvae and pupae apparently are incapable of overwintering in soybean fields, so infestation of soybean the next year begins with adult immigration (Watson 1916a, Buschman et al. 1981a).







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Soybean and VBC interact in several ways: (1) oviposition by moths, (2) foliage consumption by larvae, (3) nutritional quality of plants, and (4) canopy dynamics of the plants. Soybean serves as an ovipositional substrate (Greene et al. 1973), and differences in infestation levels on some varieties may be due to an ovipositional preference (see Genung and Green 1962). Soybean varieties and phenological stages vary nutritionally (see Hammond et al. 1951, Henderson and Kamprath 1970, Hanway and Weber 1971), and this variation significantly affects VBC development, consumption, survivorship, and reproduction (Moscardi et al. 1981a, Moscardi et al. 1981b, Reid 1975, Oliveira 1981). Also, as larvae develop, their consumption rate (cm2/day) increases: instar 2 = 0.31; instar 3 = 1.47; instar 4 = 3.94; instar 5 = 8.11; and instar 6 = 14.39 (Reid 1975).

The dynamics of the soybean canopy have an enormous effect on two aspects of VBC dynamics: (1) adult colonization and (2) larval mortality. Colonization by adults may be related to changes in soybean canopy (see Chapter IV). Canopy dynamics affect larval mortality in four ways. First, canopy closure establishes favorable microclimatic changes that can lead to an epizootic of Nomuraea rileyi (Farlow) Samson, an entomopathogenic fungus (Kish and Allen 1978). Second, mortality rates of immature VBC that have fallen to the ground are significantly higher before the canopy closes due to high soil surface temperature (Elvin 1983). Third, canopy leaf area is a key element in the predator/prey dynamics of VBC larvae. Leaf-area increase provides a spatial escape for VBC larvae (0'Neil 1984). Fourth, female moths appear to oviposit on the lowest two-thirds of the plant and small larvae are apparently distributed in the bottom third of the canopy (see Ferreira and Panizzi 1978). Mortality of eggs and small larvae may






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decrease significantly after canopy closure because closed canopies are darker than unclosed canopies and predators may not be able to see as well in a closed canopy.

The completion of the present review of the ecology of soybean and VBC, and their interactions, sets the stage for presentation of the chapters that follow. In the next chapter (Chapter III), a description of the behavioral ecology of adult VBC within soybean is presented. Observations of adult behavior in the field were necessary for the design and implementation of the experiments presented in the chapters that follow Chapter III.
















CHAPTER III
BEHAVIORAL ECOLOGY OF ADULT VELVETBEAN CATERPILLAR Introduction

Ethology, the study of behavior, has been slow to emerge as a scientific discipline (Kennedy 1972, McFarland 1976). This slow emergence seems odd, particularly with respect to pests, because pest management mandates an understanding of pest behavior (Kennedy 1972, Lloyd 1981, Gould 1984, Lockwood et al. 1984). Ignorance of the behavioral ecology of pests has led to a poor understanding of population dynamics and management (see Kennedy 1972, Stimac 1981, Burk and Caulkins 1983, Barfield and O'Neil 1984).

Insect behavioral data, particularly for pests, is limited (Nielsen 1958, Matthews and Matthews 1978). Not surprisingly, information on the behavioral ecology of adult velvetbean caterpillar (VBC), a major pest of soybean in the Gulf Coast area of the United States, is sparse (see Greene et al. 1973, Herzog and Todd 1980). The present study on the behavioral ecology of adult VBC was initiated as part of a project to explore the movement of adults into soybean. To examine this movement quantitatively, a mathematical relationship needed to be established between adult and egg densities in a soybean field (see Chapter VI). To obtain estimates of adult and egg densities (see Chapters IV and V), and to establish a relationship between these estimates, a number of questions about adult behavior in the field had to be resolved: (1) Did flight activity vary through time? (2) Did ovipositional occurrence and frequency vary through time? (3) What environmental factors affected


- 28 -






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flight activity and oviposition? and (4) What environmental factors affected the movement of adults in and out of soybean? In addressing these questions, additional behavioral observations were recorded.

Literature Review

General Activity

Circadian rhythms of locomotion for colonized adults have been determined with a vibration-sensitive actograph (Leppla 1976). Males and pairs were diurnal predominately during the first 6 days after emergence and nocturnal from the sixth day until death. Females became nocturnal within 48 h of emergence. The general activity of adults in all categories (i.e., isolated sexes and pairs) was age dependent; most activity occurred in the first week after emergence. For paired adults, 74% of all activity was expressed during the first week. Flight in the Laboratory

Circadian rhythms of flight frequency for colonized adults were determined with an actograph system (Leppla et al. 1979). Flight activity, monitored for 18 days, was exceptionally erratic. Nocturnal and diurnal flights were common during the first six days after emergence for isolated sexes and pairs. Following the sixth day, flights were nocturnal predominately. No significant differences in flight activity were noted among males, females, or pairs, but pairs exhibited the least activity and isolated females exhibited the most activity. Flight activity for all categories decreased with age.

A pivot-stick actograph was used to examine tethered flight of VBC adults (Wales et al. 1985). No significant differences were detected with regard to mean flight frequency (number of flights) or mean flight duration (time of flight) among all seven comparisons of colony versus wild adults and mated versus unmated adults. For mated and unmated






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colony females, mean daily flight frequencies were erratic, but relatively few flights were made in early adult life. No obvious patterns in the hourly distributions of flight frequency for colony or wild females, mated or unmated, were detected. For mated and unmated colony females, mean daily flight durations were erratic, but relatively short flight times were displayed in the second through fourth days. No obvious patterns in the hourly distributions of flight duration for colony or wild females, mated or unmated, were detected. Flight in the Field

Flight activity in the field can be partitioned into three

categories: (1) migratory, (2) movement among various hosts, and (3) within field. Migration of adults is reviewed in Chapter II, and movement among hosts is discussed in Chapter IV where relevant adultdensity data are presented. Reports of within-field flight activity (i.e., daily flight activity) will be reviewed in this chapter.

Watson (1915, 1916a, 1916b), the first to report on flight activity of VBC, made several observations in velvetbean, Stizolobium deeringianum Bort.


Although apparently capable of prolonged journeys, the moths as
observed in the field, do not ordinarily take long flights. They
hang about the velvet bean plants closely, coming out for short flights about sunset. If disturbed, they dart away rapidly but
usually fly only a few yards and do not rise high above the vines.
(Watson 1915, p. 59)

Dusk is the period of greatest activity of the moths. During the
day they lie hidden under the leaves of the host plants. If
disturbed they fly a short distance only. (Watson 1916a, p. 525) The moths fly mostly toward sunset, but fly up at any time during the day if the vines are disturbed as by one walking through them.
They do not rise high into the air but keep close to the ground and
where the shade of the vines is dense. (Watson 1916b, p. 11)






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Douglas (1930) indicated that adults were night-flying moths, were inactive in soybean during the day and, if disturbed, exhibited a very swift flight. Ellisor (1942, p. 18) noted:


The moths are inactive in the day, usually resting on the ground or
close to the ground on leaves or other debris, and when disturbed
make darting flights for short distances and again become inactive.
Late in the afternoon they become active and can be seen darting in
and out of the plants.


The most detailed observations of flight were reported by Greene et al. (1973). Moths were observed with a flashlight and a propane lantern in a 1.83 x 1.83 x 3.66 m screen cage placed over soybean plants in a field. "Observation of moths in daylight showed undirected flight behavior. Disturbed moths flew into the cage walls, hit leaves and other objects, and flew in undirected, sharp, angled patterns, similar to the observations by Ellisor (1942). At sunset, moth activity in the field was minor, but 30 min post-sunset, moth movement became directed, slower, and much more controlled. Moths did not fly into the cage walls; they would fly to the wall and light upon it; they would fly to a leaf, flutter, and settle upon it, and they were observed not to bump into objects. Moths on the cage walls at sundown moved to the plants and by ca. ii h postsundown few were left on the cage walls" (Greene et al. 1973, p. 1113).

Another report of flight activity in soybean was made by Gutierrez and Pulido (1978). They reported that moths were fast fliers and flew regularly during the night. During the day, moths remained on the soil surface near the soybean plants or on the middle part of the plants. Johnson et al. (1981) reported on the flight of colony males under natural photoperiod in screenwire cages in a greenhouse; females were present but were unable to fly. "Males became active ca. 45 min after






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sunset. This activity was characterized by apparently indiscriminate flight around the cage, followed by walking on the sides of the cage, and rapid fluttering of wings" (Johnson et al. 1981, p. 529). Mating

Watson (1915, p. 60) stated that, "mating undoubtedly takes place at night." Watson (1916a, p. 525) furthered his observations when "a single pair was observed mating in the cages [sic]. This occurred about dusk. They remained in coitu only a few seconds."

The first detailed observations of mating behavior were published by Greene et al. (1973). Observations were made during seven consecutive scotophase periods inside a 1.83 x 1.83 x 3.66 m screen cage placed over soybean. Male activity was observed when a female, "with her moving wings outstretched horizontally" (Greene et al. 1973, p. 1113), pointed her abdominal tip dorsally (or ventrally as in one observation). Males, usually two to five, were attracted from .61-1.83 m. A mating pheromone was postulated.

Greene et al. (1973) noted additionally that mating activity

consisted of five stages: pheromone release, male response, mounting by the male, sperm transfer, and separation. Males flew in an upwind zigzag pattern to locate a female. Females were approached from behind, stroked vigorously with the male's antennae, and mounted dorsally for 1-10 sec (x 5 sec). Males then rotated 1800 toward the rear of the female, so that their heads pointed in opposite directions. The legs of both adults were on a leaf surface, and females always faced skyward. Adults remained opposite to each other for the remainder of the copulatory period, were docile if disturbed, and moved very little.

"The majority of the copulations began within 2 h postsunset and considerably fewer after 10 PM. The time spent in copulation ranged






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from 42 min to over 4 h and averaged 2 h 31 min." (Greene et al. 1973, p. 1114). Copulations were observed on the cage wall, on the plants, and in the field outside of the cage. Under natural field conditions, mating occurred within the plant canopy, with both sexes grasping stems or leaves. At the completion of copulation, the adults separated. Usually the female walked a very short distance, remained on the same plant leaf for a few minutes, and then flew away. Male activity after separation was not described.

During a ten hour scotophase period in the laboratory, Leppla

(1976) watched 20-50 pairs of adults in three plexiglass cages over an 18-day period. No adults "called" or mated during their first day. Mating peaked during the 2nd and 3rd day and declined steadily until it stopped on the 16th day; mating activity was age-dependent. Mating occurred at all hours of scotophase, with 19% occurring in the first 5 hours and 81% occurring in the second 5 hours. Mated females contained an average of 1.7 spermatophores per female, with a range of 1-6 spermatophores. Males did not mate more than twice. "Typically, a male flew to the female, engaged in the well-known lepidopteran 'courtship dance,' approached the female from behind, moved forward to a parallel position, mounted dorsally, clasped the genitalia of the female, and swung down to face the opposite direction" (Leppla 1976, p. 47).

Johnson et al. (1981) confirmed the presence of a female sex pheromone with behavioral observations and field bioassays. Colony adults, observed in cages in a greenhouse, became active ca. 45 min after sunset, but mating was not noted until ca. 2 h after dark. The courtship sequence was initialized by a female with wing fanning and dorsal elevation of the abdominal tip. The male response consisted of flying in a zigzag path toward the female, hovering near the female






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(usually with claspers extended), and landing or flying away. In the field bioassay, male attractiveness to three females in a trap commenced ca. 1 h after sunset and remained fairly uniform throughout the night. Pheromone, extracted from females 4 h and 6 h after sunset, was more attractive to males than pheromone extracted 9 h and 6 h before dark, at sunset, or 2 h and 9 h after sunset. A significant decrease in male capture was noted with increasing age of females. Also, mated females were less attractive to males. The female sex-pheromone was identified as a blend of (Z,Z,Z)-3,6,9-eicosatriene and (Z,Z,Z)-3,6,9heneicosatriene in a blended ratio of ca 5:3, respectively (Heath et al. 1983). Synthesized pheromone elicited responses by adult males equivalent to those elicited by females in both laboratory bioassays and field-trapping experiments (Heath et al. 1983). Oviposition

Early reports of oviposition were not quantified. Watson (1916a) noted most eggs were laid singly on the bottom leaf-surface of velvetbean, but some were laid on the upper leaf-surface, petiole, and stem. He also reported oviposition on the tender shoots, the underside of the leaves (Watson 1915), mostly on the bottom of younger leaves (Watson 1916b), and mostly on the bottom of mature leaves (Watson 1916c). Watson apparently was confused as to where the majority of eggs were laid. Watson (1921, p. 2) further reported that, "the moths are shade-loving creatures and collect under the vines in the densest shade and there lay their eggs."

Douglas (1930) indicated that eggs were deposited singly on the underside of soybean leaflets and sometimes on the upper leaflet surface. Females often laid one egg per plant, sometimes several. Hinds (1930) reported that eggs were deposited singly on soybean,






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scattered about the plant and found on leaves and stems. On leaves, the midrib was preferred because the pilosity was heaviest. Oviposition was observed by Hinds (1930) at dusk and assumed to continue into the night. Observations by Ellisor (1942) indicated the following: (1) oviposition on soybean began in late afternoon and extended through the night, (2) eggs were laid singly and many eggs were laid on each plant, (3) eggs were found on the stems, seed pods, and leaves, and (4) eggs were found often on the midrib and veins of a leaflet underside.

The only detailed observations of oviposition have been presented by Greene et al. (1973). Wild adults in soybean were observed in a 1.83 x 1.83 x 3.66 m cage during scotophase over a seven-day period. Observations started at sunset (ca. 2000) and stopped at 0300, except for the first night when observations stopped at 0800. Females laid eggs singly, but two or three eggs were laid occasionally at a given site with the eggs ca. 1 cm apart. Females fluttered quickly between ovipositional sites and deposited an egg in 2-60 sec. Frequently, females exhibited ovipositional behavior but no eggs were laid. Eggs were deposited on stems, pods, and leaf bottoms.

"Oviposition was closely observed several times and consisted of the moth first clasping part of the plant with her feet, then arching the tip of her abdomen ventrally. When the plant surface was touched by her abdomen, it expanded; the conjunctiva anterior of her ovipositor became visible, and an egg was deposited. The egg was usually placed between the plant hairs close to the surface, and adhered tightly to the plant. Rain or dew did not remove the eggs, and they were nearly impossible to remove from the leaf with a camel's hair brush" (Greene et al. 1973, p. 1115).






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Oviposition occurred throughout scotophase but was most common from

0.5 h after sunset until 0200. A peak in egg laying occurred 2-4 h after sunset. Temperature, humidity, and dew were reported to affect ovipositional activity. Oviposition increased as temperature decreased and humidity increased. Also, oviposition seemed to decrease as dew accumulated, except for the first night. Dew formed from 2200 to 2400 (Greene et al. 1973).

With 20 pairs of colony adults in each of three cages, Leppla

(1976) found that egg deposition did not occur during the first 3 days after emergence, peaked on day 5, and declined from day 6 until day 18 when oviposition stopped. Relative humidity (RH) had a critical effect on colony performance. A RH of 85 5%, at least during scotophase, was required for adequate mating. Without adequate conditions for mating, few viable eggs were produced. The placement and vertical distribution of VBC eggs on soybean (cultivar UFV-I) were reported by Ferreira and Panizzi (1978). Eggs were found mainly on the lower two-thirds of plants and most were on pods (59%), some on stems (37%), and a few on leaves (4%).

Moscardi et al. (1981c) investigated the effects of temperature on oviposition, egg hatch, and adult longevity, under constant and variable temperatures. Mean total oviposition was highest at 26.70C (842.2 26.1 eggs) and steadily decreased in either direction from 26.70C to the lowest mean at 32.2C (310.0 14.7 eggs). At temperatures < 18.2C or > 32.2C, adult survival and reproductive capacity were retarded significantly. Mean percent egg hatch was (1) highest at 26.7-C, (2) not significantly different for 26.7, 29.4, or 32.20C, and (3) lowest at 21.10C. Mean longevity for mated females was longest at 21.10C (24.8

1.0 days) and steadily decreased to the shortest longevity at 32.20C






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(11.2 0.6 days). At 26.70C unmated females lived longer (22.8 0.8 days) than mated females (18.0 1.0 days). As temperature increased from 21.1 to 32.20C, mated females laid the majority of their eggs at progressively earlier ages. At all temperatures, 50% of all oviposition occurred within four to nine days after emergence and steadily declined thereafter.

Females reared from larvae maintained on different soybean

phenological stages exhibited variation in mean total oviposition, mean percent egg hatch, mean longevity and R (Moscardi et al. 1981b). "Mean
0

oviposition-rates ranged from 963.4 to 515.0 eggs/female when larvae fed on early vegetative and senescent leaves, respectively. Average dailyoviposition peaked ca. 4 days after adult emergence, decreased sharply to day 10, and remained at a low level until adult mortality. Mean daily egg-hatch decreased with female age, but female longevity was not affected significantly" (Moscardi et al. 1981b, p. 113).

Using a pivoted-stick actograph, Wales (1983) confirmed that mated females lay most of their eggs early in life. Unmated females delayed oviposition until very late in life. The hourly distribution for lab mated and wild mated females, ages one to nine days old, indicated that most eggs were laid in the first four hours of scotophase, but that oviposition occurred all night.

Feeding

Not much is known about adult feeding in the field. Hinds (1930) reported adults fed on the nectar of a Crotalaria sp. Greene et al. (1973, p. 1115) observed feeding during all hours of scotophase, "with peak activity from sundown to after 12:00 midnight [sic]." Primarily females, but also some males, fed on crushed grapes from sunset until 0230 when observations stopped. Adults fed at the seed heads of






- 38 -


bahiagrass, Paspalum notatum Flugge, throughout scotophase but most abundantly at sunset. The food source on the bahiagrass seed heads was not determined. Moths were observed to feed on dew droplets on soybean and on water in a cup. The chemical content of the dew and water was not determined.

Various honey solutions have been used for adult food in numerous laboratory studies (see Leppla 1976, Leppla et al. 1979, Johnson et al. 1981, Moscardi et al. 1981b, Moscardi et al. 1981c, Oliveira 1981, Wales 1983). The effect of variation in adult diet on oviposition and longevity was explored by Wales (1983). "Moths fed 5% or 10% honey solution had mean longevities of 19.6 and 16.4 days and mean fecundities of 846.1 and 866.2 eggs/female, respectively. Water-fed females lived 9.3 days and produced 212.7 eggs, and unfed females lived 5.7 days and produced 41.6 eggs/female" (Wales 1983, p. ix). Predators

Little is known about predators of adult VBC. Watson (1915, 1916c) reported dragonflies as predators but listed no common or scientific names. Neal (1974) reported two predatory species, the green jacket dragonfly, Erythemis simplicicollis (Say), and the striped earwig, Labidura riparia (Pallas).

Research Goals

The present study on the behavioral ecology of adult VBC was

initiated as part of a project to explore the movement of adult VBC into a soybean field (review pp. 27-28). To examine this movement, a mathematical relationship had to be established between adult and egg densities in a soybean field (see Chapter VI). To obtain estimates of adult and egg densities (see Chapters IV and V), and to establish a relationship between these estimates, a number of questions about adult






- 39 -


behavior in the field had to be resolved: (1) Did flight activity vary through time? (2) Did oviposition occurrence and frequency vary through time? (3) What environmental factors affected flight activity and oviposition? and (4) What environmental factors affected the movement of adults in and out of soybean? In addressing these questions, additional behavioral observations were recorded and are reported below.

Materials and Methods

From 1980-1982,* field observations were conducted at the

University of Florida's Green Acres Research Farm, located 22.5 km west of Gainesville, FL (Alachua County). This farm covers ca. 93 ha, and consists of crop fields, fallow fields, and wooded areas. The principal observation site was a 1 ha soybean field (cv. Bragg), but observations were made also at other sites on the farm. Agronomic practices and soybean phenological stages of each soybean field in all three years are listed in Appendix A.

All behavioral observations were made by remaining stationary or walking slowly, and were recorded verbally on a hand-held PanasonicR MicrocassetteTM Recorder, Model RN-001D. The time of each observation was recorded to the nearest minute. A six-volt EverreadyR Freedom LightTM (i.e., a head lamp) was used for nocturnal observations; the lighting fixture was covered with a section of Ziptone color sheet, Vermillion Hue #2545. Adult VBC were sexed with leg-scale morphological differences (see Anonymous 1974 and Appendix B), but were not aged. Another moth, Mocis latipes Guenee (Lepidoptera: Noctuidae),



*During the summer of 1983, a few records of adult feeding and spider predation were obtained at various localities. These records are considered ancillary to the text of this chapter but were added where appropriate and with the necessary detail.






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occurred at the study site and looked similar to VBC. Differences between adults of these two species are discussed in Appendix B.

Temperature and humidity were monitored continuously with a

hygrothermograph (Weather Measure Corporation Model No. H311). Also, temperature was monitored hourly with an Esterline AngusR PD2064 Microprocessor. Rainfall was recorded continuously by a Universal Recording Rain Gage (12" chart with dual springs, Belfort Instrument Co.). Sunset and sunrise times were obtained from Oliver* (personal communication). Phase and temporal occurrence of the moon were obtained from the Astronomical Almanac (Smith and Smith 1981, and Vohden and Smith 1982) and were noted with visual observation in the field. In 1981 and 1982, wind speed was recorded at 15 min intervals with a gill, 3-cup, anemometer (Model 12102, R. M. Young Co.). In 1981, wind direction was recorded at 15 min intervals with a gill microvane (Model 12302, R. M. Young Co.).

Quantitative Technique

The temporal occurrence and frequency of several adult activities (oviposition, mating, and feeding) during scotophase were examined quantitatively. Scotophase was partitioned into hourly increments after sunset, with the hours numbered consecutively from 1 (sunset) to 12 (sunrise). For an activity on a particular night, the amount of observation time and the number of observations were segregated according to their hour of occurrence. Observations were weighted with respect to observation time to correct for a time bias (i.e., the number of observations were divided by the amount of observation time). No



*J. P. Oliver, Associate Professor of Astronomy, Department of Astronomy, University of Florida, Gainesville, FL 32611.






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significant differences occurred between years according to the Kruskal-Wallis Test (a = .05). Therefore, weighted observations from different years, months, and nights were grouped by hour of occurrence. The sample mean of the weighted observations of each hour was calculated. These sample means were normalized, multiplied by 100 to yield percentages, and plotted against their respective hour.

Sample means were normalized by totaling the 12 hourly sample means and dividing each sample mean by the total. Normalization of the sample means allowed for proportionality among the means. Percent normalized sample means were used for ease of discussion, as opposed to the use of normalized sample means. The standard error of each sample mean was determined, normalized and multiplied by 100. A detailed explanation of the quantitative technique and the raw data are presented in Appendix C. Assumptions

To analyze the behavioral observations quantitatively, several assumptions were made: (1) an activity had an equal chance of being observed whether I was stationary or walking, (2) adult age did not affect the temporal or spatial occurrence of adult activities (i.e., observed adults were not aged), and (3) the temporal length of scotophase (sunset to sunrise) was the same for all nights.

Results and Discussion

Approximately 355 h were spent observing adult behavior (Table 3.1). The majority of the time (90%) was spent in the field during July, August, and September, and more time occurred during photophase (201 h and 19 min) than during scotophase (153 h and 13 min).

The first adult sightings in 1981 and 1982 occurred during

photophase on 3 August and 19 July, respectively. In both years, the first adults were found in areas of the field where the canopy was









Table 3.1. Amount of time dedicated to behavioral observation of adult velvetbean caterpillar in a 1
ha soybean field at the Green Acres Research Farm, Alachua County, FL, from 1980-82.




Scotophasea Observation Photophaseb Observation Time (min) Time (min) Total Observation
Month 1980c 1981 1982 Total 1980c 1981 1982 Total Time (min)



June 0 180 359 539 0 90 630 720 1259 July 0 609 1080 1689 0 876 3481 4357 6046 Aug. 180 2159 1158 3497 0 2489 1735 4224 7721 Sept. 0 1717 1401 3118 10 335 1894 2239 5357 Oct. 0 0 350 350 0 30 509 539 889

Total (min) 9193 12079 21272 Total (hr/min) 153/13 201/19 354/32


aScotophase was sunset to sunrise. bPhotophase was sunrise to sunset. c In 1980, most of the observation times were not recorded.






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almost or completely closed. The initial occurrence of adults in the field may be related to microclimatic differences in moisture (see Chapter IV). During the field season, adults were not observed in areas of the field where the canopy was open. Movement of moths out of the field in September and October coincided with the senescing of the soybean and movement into stands of wild hairy indigo (Indigofera hirsuta L.). During photophase, moths demonstrated a definite preference for residing in the field, as opposed to the edge of the field. Occasionally, adults were found at the field edge in thick clumps of grass or weeds but, regardless of the location, moths were found always on the ground or close to the ground on plants or dead plant-matter. Areas of high moisture (see Chapter IV), low light, and negligible wind appeared to be preferred. Moths were not observed in areas that were opened and exposed to sunlight and wind. Flight Activity

Flight activity was assessed qualitatively with visual

observations. When approached (or flushed) during photophase, adults flew ca. 1-10 m, landed on the ground or on low vegetation, and became immobile. Flight speed and pattern varied from slow to fast and flutter-like to darting, respectively. Flight direction was highly variable. Adults flew between rows, across rows, within the canopy, over the canopy, and demonstrated numerous combinations of these directions. Flight was controlled, and moths did not hit leaves or other objects, contrary to the report of Greene et al. (1973). Aside from flushed adults, flight activity during the day was very uncommon but consisted of flight just above the canopy and flight while feeding. See the section below entitled "Feeding" for a discussion of in-flight feeding during the day. With regard to flight just above the canopy,






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one or more moths were observed in this activity on four different days. Flight activity occurred within ca. 15 min of sunset and flight distance varied from ca. 1 m to greater than 100 m; after 100 m adults were too difficult to observe. Flight speed and pattern usually were fast and darting, respectively.

During scotophase, flight activity was highly evident and

temporally variable. During the first ca. 15 min after sunset, flight activity usually was negligible with ca. 0 to 20 flights. Between ca. 15 and 30 min after sunset, flight activity appeared to double but, on one night in September of 1980 (no record of date), several hundred adults were observed flying at this time. From ca. .5 to 2.5 h after sunset, flight activity peaked and then slowly decreased from ca. 2.5 to

4.5 h after sunset. Between 4.5 h post-sunset and sunrise, flight activity was minimal and decreased steadily to zero flights at sunrise.

Flight was utilized for oviposition, mating, feeding and,

presumably, general dispersal. Flight distance varied from ca. .01 m to greater than 100 m, but after 100 m flying adults were not observable. Flight speed and pattern varied from slow to fast and flutter-like to darting, respectively.

The most striking flight activity consisted of ca. 3 to 10 adults of unknown sex that appeared to fly in formation. Five of these formations were observed. Each occupied ca. 1 m3 in volume, occurred at or below the top of the soybean canopy, moved in one direction across or between rows, and varied in speed from moderately fast to fast. Flight paths of individual moths were highly convoluted. Formations looked like a writhing group of moths, lasted from ca. 7 to 30 sec and covered from ca. .03 to 10 m. The nature of these formations is obscure but may be involved with mating.






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Flight activity did not appear to be affected by moon phase,

moonlight, humidity, dew, wind speed or wind direction. During light rainfall, flight activity was unaffected but, during intermediate to severe rainfall, flight activity was reduced. If moderate or severe rainfall stopped between sunset and ca. 4.5 h post-sunset, flight activity resumed. If rain stopped after ca. 4.5 h post-sunset, flight activity was negligible.

Flight activity was affected by temperature. On 19 September 1981, ambient temperature decreased from 17.70C at 2000 to 11.90C at 2230, when flight activity stopped. Twenty-three adults (11 males and 12 females) were picked up or touched. None of these moths were able to fly but some slowly flapped their wings once or twice. Thus, 11.90C was designated as the lower threshold-temperature for flight activity.

In general, present observations of flight activity agree with previous observations of feral adults (see Watson 1915, 1916a, 1916b, Douglas 1930, Ellisor 1942, Greene et al. 1973, Gutierrez and Pulido 1978), but do not agree with observations of colony adults (see Leppla et al. 1979, Wales 1983). Leppla et al. (1979) found a high frequency of flight during photophase of the first six days for paired adults and Wales (1983) was unable to resolve hourly patterns of flight frequency during scotophase. Results from both studies contrast sharply with present findings. Differences among the present study and those of Leppla et al. (1979), and Wales (1983) may be an artifact of adult colonization. Colonized adults apparently behave differently than wild adults.

Mating

Of the five stages in the courtship sequence reported by Greene et al. (1973), four were observed in the field: pheromone release, male






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response, mounting by the male, and separation. Sperm transfer was not observed. Greene et al. (1973) must have assumed sperm transfer took place between coupled moths because they did not present their techniques for observation of this internal process. Greene et al. (1973) noted that calling females pointed their abdominal tip either dorsally or ventrally, and Johnson et al. (1981) noted wing fanning followed immediately by dorsal elevation of the abdominal tip. In present observations, "calling" females were observed rarely with an arched abdomen (ventrally or dorsally) or a protruding pheromone-gland. In "calling," a female positioned her feet on a plant surface; wings were extended horizontally, vibrated, and flattened to the substrate. Wing vibration was very rapid, lasted ca. 3-10 secs, and was difficult to observe because of the high frequency of the vibrations and the small vertical pitch of the wings (ca. 1-20). Typically, feral females appeared to release pheromone without abdominal arching or displaying a pheromone gland. The discrepancy among present observations and those of Johnson et al. (1981) and Greene et al. (1973) is unclear but may be due to observer interference. When releasing pheromone, moths appeared "agitated" by my light and would rapidly withdraw their pheromone gland (if everted).

During courtship, a male approached a calling female by flying in a zigzag path. This zigzag flight-path was essentially horizontal, although the male gradually descended toward the female. Male flightspeed was moderate, wing beat was flutter-like, and the male hovered briefly over the female before mounting her. The time from mounting to opposing position lasted ca. 2-10 sec. A similar time (x = 5 sec) was reported by Greene et al. (1973). Opposing position was obtained when the male swung to the left, and downward, 1800; swinging may occur to






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the right but was never observed. Following the swing manuver, both adults essentially were in the same horizontal plane, heads were pointed in opposite directions, and their abdominal ends were connected caudally (see Fig. 3.1). Typically, in opposing position, the female faced skyward and the male faced earthward. Males were observed with their feet on plant substrate or dangling in air.

Couples were immobile during the opposing position. If touched,

couples remained immobile, walked less than 5 cm, or fell to the ground or a plant structure. In falling, adults slowly fluttered their wings. Wing movement stopped upon landing and adults became immobile. Upon separation, males flew away within ca. 5 min but females remained at the copulation site for a longer but undetermined length of time. Greene et al. (1973) noted a similar scenario of immobility during copulation and of separation activities. Typically, coupled adults were not disturbed by other adults but on two separate occasions an adult male flew into and bumped a mating pair. After several bumps the males flew away. Perhaps these females were still emitting pheromone.

In 1981, 7 pairs of adults were timed for length of opposing

position. All pairs were found on soybean within one hour after sunset, and all pairs had coupled prior to their location (except for one pair). These adults may have been coupled for an hour prior to their location, but mating was uncommon in the first .5 h after sunset and was never observed during photophase (see below). Opposing position was maintained for 2 h 10 min 32 min (x SD), and this time closely agrees with that reported by Greene et al. (1973).

Adults in opposing position were observed 157 times, with 135 on soybean, 11 on beggarweed [Desmodium tortuosum (Sw.) DC.], 9 on hairy indigo (Indigofera hirsuta L.), and 2 on bahiagrass (Paspalum notatum










































Figure 3.1. Mating pair of adult velvetbean caterpillar on a soybean leaflet. Adults
are in opposing position, with the male facing downward, or earthward.
Photograph taken at Green Acres Research Farm, University of Florida,
Alachua County, FL, 19 September 1982.






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Flugge). On soybean and beggarweed, each pair was found on a leaflet. On hairy indigo, one of the opposing pairs was observed on developing seeds. The other eight pairs were found with each pair on several leaflets; a hairy indigo leaflet is smaller than a VBC adult. On bahiagrass, each opposing pair was observed on a raceme. Of the records that were kept of adult position on leaflets, the following can be noted: (1) for soybean, 29 pairs were on the bottom and 2 pairs on the top, (2) for beggarweed, 4 pairs were on the bottom and 5 pairs on the top, and (3) for hairy indigo, 1 pair was on the bottom and 1 pair on the top. No definite preference between leaflet top and bottom was noted for beggarweed or hairy indigo. A definite preference for the bottom of a soybean leaflet was noted. The relevance of this preference is unknown, but it may be a behavioral trait to avoid predation. Moths mating on the bottom of a leaflet are more difficult to see than moths on the top of a leaflet. As moths are docile and immobile during mating, adults on the top of a leaflet may be seen and preyed upon more readily by predators.

Mating occurred exclusively on legume plants, except for 2 pairs in 1980 that mated on bahiagrass at the field edge. Of the 157 observedpairs of coupled adults, 135 pairs (ca. 86%) mated on soybean, 11 pairs (ca. 7%) mated on beggarweed, and 9 pairs (ca. 6%) mated on hairy indigo. All matings on beggarweed and hairy indigo were observed in 1982, except for one pair on beggarweed in 1981.

A shift in mating site appeared to occur in late September, 1982. Limited observations in late September of 1980 and 1981 prohibited the disclosure of such a shift during those years. In 1982, the shift appeared to be from soybean to hairy indigo. Mating occurred on soybean







- 50 -


in August and September and on hairy indigo in late September in a fallow border area (see Appendix C, Table C.3). The border area was composed predominately of hairy indigo plants that were tall (ca. 1.5 m) and exhibited lush, thick vegetative growth. The shift from soybean to hairy indigo may have occurred for three reasons. First, a high moisture level is required for VBC mating (Leppla 1976). The hairy indigo appeared to maintain a high moisture microclimate, while soybean was senescing. Many leaves had fallen from the soybean and moisture around the plants was decreasing (see Chapter IV). Secondly, hairy indigo was an ovipositional site (see below). Soybean received a low complement of VBC eggs in late September (see Chapter V). Thirdly, female VBC may have been attracted to the height of the hairy indigo plants. VBC tended to mate on soybean at a height of ca. .8 m or higher. "Calling" at this height may have increased mating success through better pheromone dispersal.

Mating was observed only during scotophase, between sunset and sunrise, from 1980-82 (see Appendix C, Table C3). Mating may have occurred during photophase (sunrise to sunset), but this occurrence is doubtful, except for times close to sunset. Low levels of moisture at the canopy top during photophase should inhibit mating during photophase (see Leppla 1976 and Chapter IV). Also, predation of mating moths should be higher during photophase, as moths would be visually exposed and immobile.

Based on the percent-normalized sample means of the weighted

observations, 79.25% of all mating occurred within the first four hours after sunset [see Fig. 3.2(A) and Appendix C, Table C.4]. Greene et al.











40f
I B.
24 20
16



48
4 10 1 1
I 2 3 5 6 7 6 9 I II 2
E.


281
24


fhf~1~1f~1


5 6 ?


9 0 12


SI F.


1 2 3 4 5 6 7 8 9 1 II 12 2 3 4 5 6 7 8 3 4

G. H. I.
24

266


Ii 4


2 3 4 6 7 8 10 2 2 3 4 5 6 7 8 9 0I1 12
HOUR AFTER SUNSET


Figure 3.2.


The percent-normalized sample mean ( SE) of each post-sunset hour for activities of adult velvetbean caterpillars: (A) mating, (B) oviposition, (C) feeding, males in aggregations,
(D) feeding, males not in aggregations, (E) feeding, all males, (F) feeding, females, (G) feeding, unsexed adults, (H) feeding, males (all), females, and unsexed adults, and (I) feeding, males (not in aggregations), females, and unsexed adults. Observations were made from 1980-82 at the Green Acres Research Farm, Alachua County, FL, in a 1 ha soybean field.


D.






]f'l[~li]


.2


2



11 I '-, I :







- 52 -


(1973) obtained similar results and found that 66%* of all mating occurred over the same time period. Both of our results contrast sharply with those of Leppla (1976), where 81%** of all mating for colony adults occurred in hours 6-10 of scotophase.

The difference in Leppla's (1976) results from the results in this study and from Greene et al. (1973) may be related to (1) colony artifact, (2) temperature and predation, (3) moisture, or (4) reproductive isolation. Colony adults may mate at a different time from feral adults due to colonization. As noted above, colony adults do behave differently than feral adults with regard to the temporal occurrence of flight. With regard to temperature and predation, colony adults are maintained at a constant temperature and are not exposed to predation. Wild adults are exposed to variable and cyclic temperatures (See NOAA 1982) and should be vulnerable to predation when mating at certain times, as moths are highly visible and very docile. If mating is temperature-dependent, more time will be required to complete mating as temperature decreases during the night. Wild moths that mate in early scotophase will complete mating before sunrise. Wild moths that mate in late scotophase probably will not complete mating before sunrise and will be exposed visually to predators. In a colony with constant temperature and a lack of predation, females may "assess" the temperature/predator risk and mate during late scotophase. Mating by colony adults in late scotophase may favor the completion of a more beneficial activity during early scotophase (e.g., oviposition). Also,



*Percentage value determined with calculations of data in Table 1 of Greene et al. (1973, p. 1114).

**Percentage value determined with calculations of data in Fig. 3 of
Leppla (1976, p. 47).







- 52 -


(1973) obtained similar results and found that 66%* of all mating occurred over the same time period. Both of our results contrast sharply with those of Leppla (1976), where 81%** of all mating for colony adults occurred in hours 6-10 of scotophase.

The difference in Leppla's (1976) results from the results in this study and from Greene et al. (1973) may be related to (1) colony artifact, (2) temperature and predation, (3) moisture, or (4) reproductive isolation. Colony adults may mate at a different time from feral adults due to colonization. As noted above, colony adults do behave differently than feral adults with regard to the temporal occurrence of flight. With regard to temperature and predation, colony adults are maintained at a constant temperature and are not exposed to predation. Wild adults are exposed to variable and cyclic temperatures (See NOAA 1982) and should be vulnerable to predation when mating at certain times, as moths are highly visible and very docile. If mating is temperature-dependent, more time will be required to complete mating as temperature decreases during the night. Wild moths that mate in early scotophase will complete mating before sunrise. Wild moths that mate in late scotophase probably will not complete mating before sunrise and will be exposed visually to predators. In a colony with constant temperature and a lack of predation, females may "assess" the temperature/predator risk and mate during late scotophase. Mating by colony adults in late scotophase may favor the completion of a more beneficial activity during early scotophase (e.g., oviposition). Also,



*Percentage value determined with calculations of data in Table 1 of Greene et al. (1973, p. 1114).

**Percentage value determined with calculations of data in Fig. 3 of
Leppla (1976, p. 47).







- 54 -


The temporal occurrence of oviposition in the field may be due to the selective pressures of egg predators and parasites. Eggs are mint green when laid (see below and Chapter V) and are easy to see on soybean. As eggs age, they develop a speckling pattern (see below and Chapter V) and are extremely difficult to see on a plant (i.e., speckled eggs are cryptic). The occurrence of this speckling pattern is temperature dependent (see Chapter V). Eggs laid during early scotophase speckle at or just after sunrise (see Chapter V) and probably are difficult for predators to see. Eggs laid during late scotophase are still mint green after sunrise, are easy to see, and probably are exposed to more predation. Females that oviposit in early scotophase should demonstrate a higher reproductive fitness over females that lay eggs in late scotophase.

Oviposition was difficult to observe. Only 121 sightings were made during the 153 h 13 min of scotophase observation (see Appendix C, Table C.5). Female density may have affected the viewing of oviposition. In 1982, an estimate of female absolute density in the field was obtained at weekly intervals with an adult trap-cage (Table 3.2, see also Chapter IV). Estimates of female density were highest from August 26 to September 23. Interestingly, 61 of 73 ovipositional sightings (81%) were made at this time with an investment of only 41% of total observation time (1764 of 4348 min)(see Appendix C, Table C.5). Obviously, a productive time period to view oviposition occurred when total female density was greater than ca. 764 individuals. Concentration of more observation time during this time period may have generated more sightings.

Flight speed of ovipositing females was moderate and wing beat was flutter-like. The distance between ovipositional sites varied from ca.







- 55 -


Table 3.2.


Estimates of the absolute density of adult females of the velvetbean caterpillar in a soybean field. Density was determined with an adult trap-cage (see Chapter IV) in 1982 at the Green Acres Research Farm, Alachua County, FL.


Date


Absolute Density of Adult Females (number/.87 ha)


July 15 July 22 July 29 August 5 August 12 August 19 August 26 September 2 September 9 September 16 September 23 September 30 October 7 October 14


0 0 0

416.8 347.3 416.8 1806.2 2570.4 2292.5 694.7 764.1 208.4 347.3 416.8







- 56 -


.10 to 1.25 m, based on visual estimates. When ovipositing on a leaflet, a female (1) landed on the leaflet, (2) moved her abdominal tip back and forth across the leaflet surface and sometimes walked at the same time, (3) positioned her abdominal tip against a leaflet vein, (4) arched her abdomen with the abdominal tip directed downward, (5) pressed her abdominal tip against the leaflet surface and the vein, exposing the conjunctiva anterior of the ovipositor, and (6) laid an egg. Oviposition on plant structures other than leaflets followed the same procedure, with the obvious exception that eggs were not laid on leaflet veins. Time required to lay an egg varied from ca. 2 to 30 sec, and eggs were glued to the surface and trichomes of the plant structure. Twenty-four hours later, eggs were impossible to remove without crushing. Contrary to present observations, Greene et al. (1973) indicated that eggs were nearly impossible to remove immediately after oviposition and that oviposition occurred in 2-60 sec, twice as much time as observed here.

All eggs were laid singly on leaflets, pulvini, or petioles, except for 19 September 1981 (ca. 2000) when one female laid seven eggs on a leaflet and another female attempted to lay three eggs on a leaflet. Low ambient temperature (17.7C) affected the behavior of these two females. While ovipositing, both females continuously vibrated their wings, a previously unobserved ovipositional activity. Presumably, wing vibration allowed for ovipositonal activity at this temperature; wing vibration without flight in Lepidoptera allows for activities at suboptimal temperatures (Chapman 1971). Both females vibrated their wings for ca. 1 min before flying to another leaflet. Their flight speed was very slow and wing beat was flap-like.







- 57 -


At 2230 on 19 September 1981, all flight and oviposition stopped when the temperature fell to 11.90C. Twelve females were picked-up or touched and none were able to fly. Most remained very rigid and did not move, but a few flapped their wings once or twice, or took a few steps. Evidently, 11.90C is near the lower threshold for oviposition. Overall, these observations indicate that temperature affects egg dispersion and deposition.

Greene et al. (1973) found that ovipositional activity increased with decreasing temperature. Neither my results nor those of Moscardi et al. (1981c) agree with the findings of Greene et al. (1973). Moscardi et al. (1981c) found that mean total oviposition varied significantly with temperature (Table 3.3). In a linear regression of their data and the assumed ovipositional threshold of 11.90C* (see Fig.

3.3), a correlation (r2 = .75, n = 74) was found between total oviposition per female and temperature with the model:

y = -694.97 + 58.40(x),

where y = total oviposition per female, and

x = temperature between 11.9 and 26.70C.

Slope and intercept parameters were determined with observations and not mean estimates, but mean estimates are shown in Fig. 3.3 for ease of view. The regression line was forced through the x intercept at 11.9C.

No other weather factors besides photophase and temperature were observed visually to affect oviposition (i.e., humidity, rainfall, moonlight, wind speed and wind direction). Greene et al. (1973) found



*Data used in the regression are listed in Appendix C, Table C.7. Data of Moscardi et al. (1981c) were stored on computer cards in Building 175, Insect Population Dynamics Laboratory, at the University of Florida, Gainesville, FL, at the time that this regression model was calculated.







- 58 -


Table 3.3.


Mean total oviposition by adult females of the velvetbean caterpillar reared from eggs at constant temperatures, 14L:IOD photoperiod, and RH > 80% (modified from Moscardi et al. 1981c).


Temperature Number of Mean
(oC) Mated Females Total-Eggs/Female ( SE)a



21.1 19 482.8 21.3C 23.9 29 732.3 22.9B 26.7 25 842.2 26.1A 29.4 15 713.5 28.1B 32.2 19 310.0 14.7D



aMeans followed by the same letter are not significantly different according to Duncan's multiple range test (a = .05).







- 59 -


900 r


600


300


10 13 16 19 22 25


TEMPERATURE (oC)


Figure 3.3.


Linear relationship between total eggs per velvetbean caterpillar adult female and temperature. Regression line is y = -694.97 + 58.40(x), (r2 = .75, n = 74), where y = total oviposition per female, and x = temperature between 11.9 and 26.70C. Mean estimates are shown in the figure for ease of view. Data are from Moscardi et al. (1981c), while the assumed threshold temperature is from field observations at Green Acres Research Farm, Alachua County, FL.







- 60 -


oviposition was more common as RH increased and less common as dew formed during scotophase. Current observations do not support the findings of Greene et al. (1973) for the following reasons: (1) RH during the first hour after sunset was typically lower than all other hours during scotophase (see NOAA 1982), (2) the highest percentage of oviposition [29%, see Fig. 3.2(B)] occurred during the first hour post-sunset, and (3) females were observed frequently to oviposit after dew set.

Fifty-four of the 121 ovipositional sites were searched for eggs; at 20 sites eggs were found, at 34 sites no eggs were found, and no search was made at 67 sites. Greene et al. (1973) noted also that females exhibit ovipositional behavior without leaving an egg. The nature of this behavior is obscure, but at least three possible explanations exist: (1) eggs may not adhere to substrate, (2) females may lack a proper ovipositional cue, and (3) females might leave egg kairomones that may "confuse" egg predators and parasites.

Of the twenty sightings at which an egg was laid, all eggs were light green in color. Twenty-four hours later, all eggs had numerous small reddish-brown speckles over a light-green background color. These small reddish-brown speckles indicated egg viability (see Chapter V).

Oviposition was observed on soybean 48 times (1981) and 72 times (1982), and on hairy indigo one time (1982). On soybean, all ovipositions occurred on leaflets except for one sighting each on a pulvinus and on a petiole. Fourteen records were kept of egg placement on leaflets. Thirteen eggs were placed by main veins and one egg was placed by a secondary vein. All eggs were glued to the plant substrate and to closely associated trichomes. Trichome density on the leaflets







- 61 -


was highest along the main vein and less dense along the secondary veins. Pulvini were covered in a thick "carpet" of trichomes and petioles had trichomes that occurred in longitudinal rows. Both Hinds (1930) and Ellisor (1942) noted an ovipositional preference for areas of high trichome density.

Feeding

More individuals were observed feeding than for any other activity. A total of 458 individuals were sighted: 268 males, 129 females, and 61 unsexed adults (Table 3.4). Unsexed adults flew away before a positive sexual identification could be made. Feeding occurred predominately at night, when 448 of the moths (or 98%) were observed (Table 3.4).

When feeding, the proboscis was extended, touched the food source, and was maneuvered across the food source surface. Except for flowers, all moths were observed to feed on moist surfaces. This moisture was either rain water, dew, plant-guttated water, or plant exudates. When feeding at a flower, a moth would probe the flower with its proboscis. The attainment of nectar or pollen was not assessed. No adults were observed to feed at soybean flowers and none of the food sources were chemically analyzed.

Overall, feeding was the easiest behavioral activity to observe. At night, adults were easy to approach and observe. Individuals "rested" on an available substrate while feeding, as opposed to flying. During the day, adults were more difficult to approach and observe. On six occasions, moths were observed feeding at flowers (Table 3.5). These moths hovered in flight while feeding, were in the open, and were easy to see. When approached from ca. 1.5 m moths stopped feeding, flew a short distance and "hid" among weeds. Apparently, adults can see very







- 62 -


Table 3.4.


Number of unsexed, male, and female adults of the velvetbean caterpillar observed feeding in a soybean field at Green Acres Research Farm, Alachua County, FL, in 1980-82.


Temporal Unsexedc
Occurrence Adults Male Female Total



Photophasea 8 1 1 10 Scotophaseb 53 267 128 448 Total 61 268 129 458


aPhotophase = sunrise to sunset. bScotophase = sunset to sunrise. cUnsexed adults flew out of sight identification could be made.


before sexual









Table 3.5. Observational records of feeding by adult velvetbean caterpillar during photophase at the Green
Acres Research Farm, Alachua County, FL, from 1980-83.




Time of Time of Time Before Number of b Date Sunset Observation Sunset (h/min) Adults Adult Sexa Food Source



19 September 1980 1930 1900 0/30 2 Adult Horse Mint 20 September 1980 1928 1900 0/28 2 Adult Horse Mint 24 September 1982 1923 1900 0/23 2 Adult Hairy Indigo 02 October 1982 1914 1515 3/59 1 Female Hairy Indigo 2 Adult Hairy Indigo

02 October 1982 1914 1535 3/39 I Male Hairy Indigo 08 November 1983c 1739 1730 0/09 2 Female Common Beggar Tick


aSexually unidentified moths are listed as adult. bThe food source was always at a flower. Horse Mint is Monarda punctata L. Hairy Indigo is Indigofera hirsuta L. Common Beggar Tick is Bidens alba (L.) DC. cObserved on the campus of the University of Florida, Ganesville, FL. Observed on the campus of the University of Florida, Gainesville, FL.







- 64 -


well in daylight or detect human presence. Why these moths stopped feeding and flew is unknown.

A definite preference for feeding sites at the edge of the field ( ca. 2 m) was exhibited, where ca. 57% (261 of 458 adults) of all feeding was observed. Of the 197 observations in the field, 163 were of adult males at human-altered feeding sites. Re-examination of the data without these human-altered sites reveals that ca. 88% (261 of 295 adults) of all feeding occurred at the edge of the field. Due to the strong bias of feeding at field-edge sites, and because most observation time was spent in the field and not at the field edge, results on the temporal occurrence of feeding should be viewed with caution. Proper assessment of the temporal occurrence of feeding should be examined with a separate study.

Adults fed at numerous sites (Tables 3.6-3.8). The most striking feature about site selection was the dichotomy between male and female sites. Although males and females shared common sites (Table 3.7), some sites were visited strictly by males (Table 3.8). At these sites, males were observed usually in aggregations of two or more individuals (see Figs. 3.4 and 3.5). Of the 179 males at these sites, 159 were found in aggregates, and 121 of these aggregated males were on aerial and sweep nets (bags and poles). These nets were used frequently in the field (soybean and fallow areas) to collect arthropods, were stained heavily with arthropod and plant substances, and were coated with human sweat and oil. The Saran Screens, additional sites of male aggregations, were handled also by people and coated with human sweat and oil. Male aggregations were observed only at human-altered sites and not at naturally occurring sites. When feeding in aggregates, males were










Table 3.6. Number of unsexed adultsa of the velvetbean caterpillar observed feeding in a soybean
field at Green Acres Research Farm, Alachua County, FL, in 1980-82. Description of food
site and host provided.




Food Host

No. of Unsexedb Foodc
Adults Feeding Site Common Name Scientific Name Family



4 Flower Horse Mint Monarda puntata L. Labiatae

43 Raceme Bahiagrass Paspalum notatum Flugge Gramineae

2 Raceme Unknown Grass --- Gramineae 1 Flower, Unopened Florida Pusley Richardia scabra L. Rubiaceae

6 Flower, Outside Hairy Indigo Indigofera hirsuta L. Leguminosae 5 Flower Hairy Indigo Indigofera hirsuta L. Leguminosae




aunsexed adults flew out of sight before a positive sexual identification could be made. bTotal = 61.

cAdults fed at the surfaces of plant structures or in flowers.













Table 3.7. Number of male and female adults of the velvetbean caterpillar feeding in
a soybean field at Green Acres Research Farm, Alachua County, FL, from
1980-82. Description of food site and host provided.




No. ofa No. ofb Food Host Males Females
Feeding Feeding Food Sitec Common Name Scientific Name Family


I 1 Seed Slender Amaranth Amaranthus viridia L. Amaranthaceae
50 84 Raceme Bahlagrass Paspalum notatum Flugge Gramineae
12 11 Leaflet Soybean Glycine max (L.) Herr. Leguminosae 3 2 Leaflet, Dead Soybean Glycine max (L.) Herr. Leguminosae
0 1 Stem, Dead Unknown Plantd ..
3 2 Leaflet, Dead Beggarveed Desmodium tortuosum (Sw.) DC. Legumlnosae 2 2 Roots, Stems, Dead Beggarweed Desmodium tortuosum (Sw.) DC. Leguminosae 1 0 Seed Beggarweed Desmodium tortuosum (Sw.) DC. Leguminosae
0 1 Seed Florida Pusley Richardia scabra L. Rubiaceae
3 2 Leaflet Sicklepod Cassia obtusifolia L. Leguminosae 2 2 Flower, Outside Hairy Indigo Indigofera hirsuta L. Leguminosae I I Flower, Outside, Dead Hairy Indigo Indigofera hirsuta L. Leguminosae 9 18 Flower Hairy Indigo Indigofera hirsuta L. Leguminosae 2 0 Leaflet Hairy Indigo Indigofera hirsuta L. Leguminosae 0 2 Leaflet, Dead Hairy Indigo Indigofera hirauta L. Leguminosae O 2 Flower Common Beggar Tick Bidens alba (L.) DC. Compositae

aTotal males 89.

bTotal females 131.

c
Adults fed at the surfaces of plant structures or in flowers. dDicotyledonous plant.









Table 3.8.


Number of adult males of the velvetbean caterpillar feeding in a soybean field at Green Acres Research Farm, Alachua County, FL, from 1980-82. Also, number of males per aggregate, number of aggregates, and description of food site are provided.


No. ofa No. of Malesb No. ofc
Males Feeding Per Aggregate Aggregates Description of Food Sited



5 0 0 Human Skin
4 0 0 Vinyl Raincoat
1 0 0 White Cotton Pants
1 0 0 Aluminium Push Button, Head Lamp
3 0 0 Bamboo Sticks
123 29, 22, 18, 17, 12, 10 Aerial and Sweep Nets (Bag and Pole) 9, 5, 3, 3, 3
16 15 1 Black Saran Screen 24 15, 5, 3 3 Brown Saran Screen
2 0 0 Barb Wire Fence


aTotal Male Feeding = 179. bTotal Males in Aggregates = 159.

c
Total Aggregates = 14. dMales fed at the surfaces of food sites.





- 68 -


Figure 3.4.


Aggregation of velvetbean caterpillar males on an aerial net. Males are feeding at the surface of the net (bag and pole). Photograph was made in a 1 ha soybean field at the Green Acres Research Farm, Alachua County, FL, September 7, 1983.











































Figure 3.5.


I


























Aggregation of velvetbean caterpillar males on the screen of an insectary. Males are feeding at the surface of the screen. Photograph was taken at the edge of a 1 ha soybean field at the Green Acres Research Farm, Alachua County, FL, September 14, 1983.


j


J







- 70 -


extremely docile and could be touched frequently without cessation of feeding. How males were attracted to these sites is unknown, but they may have utilized these sites to acquire salts, as some male lepidoptera aggregate and acquire salts (see Arms et al. 1974).

The most prevalent feeding site was the raceme of bahiagrass,

accounting for 177 (39%) of all observations (see Tables 3.4, 3.6 and

3.7). Fifty males and 84 females were observed, for a sex-bias ratio of 1:1.7 (male to female). The nature of this bias (if valid) is unknown, as is the nutritional source obtained on or from the bahiagrass. An adult is shown feeding at a raceme of bahiagrass in Fig. 3.6. Adults fed frequently on legumes, accounting for 99 (22%) of the observations (see Tables 3.4 and 3.5-3.7). No sexual bias was noted. These adults may have acquired various plant compounds, but the compounds and their utilization are unknown. Nineteen adults fed at dead plant tissue, and no sexual bias was exhibited (see Table 3.7 and Fig. 3.7). With one exception, these dead tissues were all from legumes. The compounds acquired from these dead plant tissues, as well as their utilization, are unknown. Some moths of the Ctenuchidae and Arctiidae feed on dead and withered plants as a possible nitrogen source (see Goss 1979).

The occurrence of males feeding in aggregations was an uncommon

sight in the field and contributed to the large standard errors shown in Fig. 3.2(C) (see also Appendix C, Table C.9). Male aggregations may have been found more often if an effort had been devoted solely to aggregate location during each observation period. Observation of additional aggregates may have resulted in smaller standard errors, as well as a different temporal pattern in their occurrence. Nevertheless, males were prevalent in aggregates during the fifth hour after sunset





- 71 -


Figure 3.6. Adult velvetbean caterpillar feeding at the surface of a
bahiagrass raceme. Photograph was made at the edge of a 1 ha soybean field on the Green Acres Research Farm, Alachua
County, FL, 16 September 1985.











































Figure 3.7. Adult velvetbean caterpillar feeding at the surface of a dead soybean leaflet. Photograph
was made in a soybean field in Melrose, FL, Alachua County, 7 October 1983.







- 73 -


when ca. 60% of all aggregated males were observed. Interestingly, almost all mating (79.25%) occurred in the first four hours after sunset, but the adaptive significance of the temporal relationship between mating and aggregating is obscure.

Feeding by non-aggregated males occurred throughout scotophase, except for the seventh hour when no feeding was recorded [Fig. 3.2(D) and Appendix C, Table C.10]J. Feeding by males probably occurred in the seventh hour but only four observational periods were completed at this time. The temporal occurrence of feeding by all males (aggregated and non-aggregated) was non-uniformly distributed throughout scotophase, as ca. 82% occurred within the first 6 h after sunset [see Fig. 3.2(D) and Appendix C, Table C.11]. This non-uniform distribution was dominated by the fifth post-sunset hour (43.65%) when large numbers of males aggregated. Leppla (1976) found that colony males fed uniformly throughout scotophase.

The temporal occurrence of feeding by females was non-uniformly

distributed, as 74.67% occurred between hours 5 and 11 post-sunset [see Fig. 3.2(F), Appendix C, Table C.12]. The sample mean of hour 8 accounted for 32% of all female feeding, but why is unknown. Interestingly, the first four hours post-sunset appeared to be devoted to mating and oviposition when 79.25% and 84.72% of each activity occurred, respectively. Females apparently partitioned their time between feeding, mating, and ovipositing and may have acquired an increased reproductive fitness from this partitioning (i.e., ovipositing and mating during early scotophase may be more beneficial than feeding). Leppla (1976) found that colony females fed throughout scotophase but that feeding increased during the second half of scotophase.






- 74 -


The temporal occurrence of feeding by unsexed adults was reasonably uniform throughout the night [see Fig. 3.2(G) and Appendix C, Table C.13]; unsexed adults flew out of sight before a positive sexual identification could be made. The uniform inability to sexually identify adults indicates no temporal bias occurred in identification of unsexed adults during scotophase. The occurrence of feeding by all adults (males, females, and unsexed) differed noteable for hours five, eight, and twelve [see Fig. 3.2(H) and Appendix C, Table C.14]. These hours corresponded, respectively, to peaks in male (aggregated) and female feeding and to no feeding at all. The feeding occurrence of males (not aggregated), females, and unsexed adults was different, particularly for the eighth hour, which corresponded to peak female feeding [see Fig. 3.2(I) and Appendix C, Table C.15]. Overall, feeding by VBC adults occurred at all hours of the night (except for the 12th hour).

Predators

Spiders were the only observed predators of VBC adults. No effort was made to identify all the spider species at the study site or to obtain density estimates of the recorded spider predators. Peucetia viridans (Hentz) and Misumenops spp. were the most frequently observed spiders. Peucetia viridans was found throughout the field (edge and interior), usually on dicotyledonous plants and high above the ground (ca. 1 m or higher). Misumenops spp. were found only at the field edge, usually on monocotyledonous plants and close to the ground (ca. .5 m or less). Most of the orbweavers were found at the field edge, with webs at a height between ca. .5 and 1.5 m.

Six species of spiders were recorded as predators, with 26

predation records (see Table 3.9); all records were obtained during












Table 3.9.


Records of spider predation on adult velvetbean caterpillar (VBC) from 1980-83 at Green Acres Research Farm, Alachua County, FL, in a 1 ha soybean field. All records occurred during scotophase.


Spidere
Spider Stage VBC Datea b Common Spider and Adult (D-M-Y) Time Location Spider Scientific Named Name Family Sex Sex


Bahlagrass Soybean Florida Pasley Bahiagrass Sandbur Soybean Soybean Soybean Beggarweed Sicklepod Hairy Indigo Soybean Sicklepod Soybean Soybean Grass
Soybean Bahlagrass


Peucetia viridana (Hentz) Peucetia viridana (Hentz) Peucetia viridans (Hentz) Peucetla viridans (Hentz) Peucetia viridans (Hentz) Peucetia viridans (Hentz) Peucetia viridana (Hentz) Peucetia viridans (Hentz) Peucetia viridans (Hentz) Peucetia viridans (Hentz) Peucetia viridans (Hentz) Peucetia viridans (Hentz) Peucetia viridana (Hentz) Peucetia viridana (Hentz) Peucetta viridana (Hentz) Peuceria viridans (Hentz) Peucetia viridana (Hentz) Misumenope celer (Hentz)


Green Lynx Green Lynx Green Lynx Green Lynx Green Lynx Green Lynx Green Lynx Green Lynx Green Lynx Green Lynx Green Lynx Green Lynx Green Lynx Green Lynx Green Lynx Green Lynx Green Lynx Crab


Oxyopidae *, + Oxyopidae + Oxyopidae + Oxyopidae + Oxyopidae * Oxyopidae + Oxyopidae + Oxyopidae + Oxyopidae A, + Oxyopidae A, + Oxyopidae *, + Oxyopidae A, + Oxyopidae A, F Oxyopidae *, + Oxyopidae I, + Oxyopidae *, + Oxyoptdae *, + Thomisidae A, +


19-S-81 19-S-81
24-S-82 17-S-81 19-S-83
24-S-82 24-S-82 09-S-81
03-S-82 03-S-82
25-S-82 04-S-82
04-S-82
04-S-82 21 I-A-81 25-A-81
15-S-81 03-S-81


2047 2058
2112 2115 2130
2147 2223 2303 2323
2340 0023 0052 0111 0136 0545-0701 0545-0703
0545-0714 2230











Table 3.9 (continued)


Spidere
Datea Spider Stage VBC
Db c dCommon Spider and Adult (D-M-Y) Time Location Spider Scientific Named Name Family Sex Sex



16-A-81 0000-0700 E, Grass Misumenops celer (Hentz) Crab Thomisidae A, + M 09-0-82 0530 E, Hairy Indigo Misumenops celer (Hentz) Crab Thomisidae A, + M 01-S-81 0545-0607 E, Grass Hisumenops celer (Hentz) Crab Thomisidae A, + F 15-S-81 0545-0714 E, Bahiagrass Misumenops formocipes (Walckenaer) Crab Thomisidae A, F M 17-S-81 2100 I, Soybean Eriophora ravilla (C. L. Koch) Orbweaver Araneidae A, F M 24-S-82 2332 E. Soybean Neoscona arabeaca (Walckenaer) Orbweaver Araneidae A, F M 05-0-82 0550 E, Soybean Neoscona arabesca (Walckenaer) Orbweaver Araneidae A, + M 15-S-83 0200 E, Bahiagrass Acanthepelra sp. Orbweaver Araneidae I, + F



a
D-M-Y Date, Month, Year; A August, S September, O October; 81 1981, 82 1982, 83 1983. bIf the exact time of a predation record is not given, the record occurred during the hyperated times.

c
E = Edge of field; record was observed within I m of the field edge. I = Inside field; record was observed in the field and at least I m from the field edge. Grass unidentified grass. Bahiagrass Paspalum notatum Flugge. Hairy Indigo = Indigofera hirsuta L. Soybean Glycine max (L.) Merr. Beggarweed Desmodium tortuosum (Sw.) DC. Sicklepod Cassia obtusifolia L. Florida Pusley Richardia scabra L. Sandbur Cenchrus op. dExcept for P. viridans, all spiders were identified by Dr. G. B. Edwards, Taxonomic Acarologist and Curator, Florida State Collection of Arthropods, Gainesville, FL. P. viridans' were identified by the author, but four of these specimens were reconfirmed by Dr. Edwards.
e
eI = immature, A adult, F female, undetermined stage, + undetermined sex. + = undetermined sex, H male, F female






- 77 -


scotophase. A male-prey bias exists, as 20 of 26 prey were males; adult VBC sex-ratio was ca. 1:1 (see Chapter IV). The nature of this bias is unknown but may be due to aggressive chemical mimicry of VBC matingpheromone by some or all of these spiders (see Foelix 1982).

Most of the predation records, 17 out of 26 (65%), were of P.

viridens. Fourteen of these records occurred between 2047 and 0136, the time period when VBC adults were most active. Misumenops spp. accounted for 5 of the 26 records (19%) and the orbweavers accounted for 4 of the 26 records (15%). The large number of P. viridens records may be a reflection of where observation time was concentrated (i.e., in the field). Also, the webs of orbweavers were destroyed frequently by research personnel walking through the field. Figures 3.8 and 3.9 are photographs of two spider predation records.

Conclusions

The temporal patterns of several adult activities (flight, mating, oviposition, and feeding) were observed and quantified in the present study, as were some environmental factors that affected these patterns. The suspected adaptive significance of these activity patterns was discussed. Flight occurred primarily at night. During the day, adults resided in the field but only after the soybean canopy had begun to close or was closed. During the day adults flew only when disturbed or rarely if feeding. Approximately 79% of all mating occurred within the first four hours of scotophase. Mating occurred usually at the top of soybean plants, a height of ca. .8 m. Placement of pheromone traps near the canopy top in the field would result probably in the largest capture of males. Approximately 96% of all oviposition occurred within the first six hours of scotophase and feeding occurred primarily at night. Females utilized nutritional sources that may have affected egg











































Figure 3.8. Green lynx spider [Peucetia viridans (Hentz)] preying on an adult male velvetbean
caterpillar. Photograph was made at the edge of a 1 ha soybean field at the Green Acres
Research Farm, Alachua County, FL, 19 September 1983.











































Figure 3.9. Orbweaver spider (Acanthepeira sp.) preying on an adult female velvetbean caterpillar.
Photograph was made at the edge of a 1 ha soybean field at the Green Acres Research
Farm, Alachua County, FL, 15 September 1983.






- 80 -


production. Males utilized some food sources that females did not use. At these sources, males usually occurred in aggregations. Future research efforts might examine more quantitatively the affect of adult age, adult nutrition, host plant density and physiology, and weather factors on flight, mating, oviposition, and feeding. Some of these efforts might be accomplished by observing individual moths.

Observations of adult activities were density-dependent. Sightings of mating, oviposition, feeding, and mortality were not observed in June and July at low adult density, but were observed in August, September, and early October at high adult density (see Chapter IV for adult density data). In future studies of adult behavior, concentration of observation time during high adult density should yield more behavioral observations.

The present study has expanded our knowledge of VBC behavior and provided information essential for the construction of a model of adult and egg populations (see Chapter VI). Knowledge of the temporal occurrence of flight and some environmental factors affecting flight allowed for the development of an unique adult sampling method (and the subsequent acquisition of adult density data) and a better understanding of adult density fluctuations (see Chapter IV). Knowledge of the temporal occurrence of oviposition allowed for the development of an unique sampling method for eggs and the subsequent acquisition of egg density data (see Chapter V). The measurements of adult and egg densities are presented in the next two chapters. These density measurements were necessary for model construction and validation (see Chapter VI).




Full Text
- 254 -
Pseudoplusia includens (Walker)
Common Name:
Soybean Looper.
Family:
Noctuidae.
Egg Development,
Color-Changes and Types:
Freshly Laid
Off white, light green. Tends to
reflect small patches of color that are
iridescent or opal like [Fig. E.4(A)].
Middle Aged
Same as freshly laid.
Old (Pre-Eclosion)
Light brown with a visible larval
head-capsule, eyes and mandibles [Fig.
E.4(B)].
Parasitized
Black [Fig. E.4(C-G)].
Parasitoid Emerging
Black [Fig. E.4 (D-G)].
Parasitoid
Trichogramma sp. [Fig. E.4(E-H)].
Egg Shape: Top View
Circular.
Side View
A flattened dome or half circle. Egg
in Fig. E.4(D) was removed from
substrate and positioned for
photograph.
Ridge Number:
x SD = 34.1 2.8, range 30-40, n =
19.
Ridge Morphology:
Not distinct, very difficult to count.
Micropylar Area:
Flat, very undefined, very difficult to
see. Ridges appear to gradually
diminish into center of micropylar
area.


- 43 -
almost or completely closed. The initial occurrence of adults in the
field may be related to microclimatic differences in moisture (see
Chapter IV). During the field season, adults were not observed in areas
of the field where the canopy was open. Movement of moths out of the
field in September and October coincided with the senescing of the
soybean and movement into stands of wild hairy indigo (Indigofera
hirsuta L.). During photophase, moths demonstrated a definite
preference for residing in the field, as opposed to the edge of the
field. Occasionally, adults were found at the field edge in thick
clumps of grass or weeds but, regardless of the location, moths were
found always on the ground or close to the ground on plants or dead
plant-matter. Areas of high moisture (see Chapter IV), low light, and
negligible wind appeared to be preferred. Moths were not observed in
areas that were opened and exposed to sunlight and wind.
Flight Activity
Flight activity was assessed qualitatively with visual
observations. When approached (or flushed) during photophase, adults
flew ca. 1-10 m, landed on the ground or on low vegetation, and became
immobile. Flight speed and pattern varied from slow to fast and
flutter-like to darting, respectively. Flight direction was highly
variable. Adults flew between rows, across rows, within the canopy,
over the canopy, and demonstrated numerous combinations of these
directions. Flight was controlled, and moths did not hit leaves or
other objects, contrary to the report of Greene et al. (1973). Aside
from flushed adults, flight activity during the day was very uncommon
but consisted of flight just above the canopy and flight while feeding.
See the section below entitled "Feeding" for a discussion of in-flight
feeding during the day. With regard to flight just above the canopy,


134 -
Functions for Oviposition
Ovipositional rate (OVI) is represented in two ways: (1) by a
constant, and (2) by a variable. OVI is the total number of eggs
oviposited per female per night in the field. In the first function,
OVI is set at a constant value of 220. This value yielded more adequate
model behavior than other constant values (see below). Also, this value
was less than the highest ovipositional rate reported in the literature
(see Olivera 1981). In the second function, OVI is variable:
r
0
if
1
<
SOY
<
5
40
if
5
<
SOY
<
9
220
if
9
<
SOY
<
14
o
00
if
14
<
SOY
<
15
210
if
15
<
SOY
<
17
60
if
17
<
SOY
<
19
0
if
19
<
SOY
<
20,
V
where SOY represents the soybean phenological stage. Values of SOY were
determined by modifying the soybean phenological system developed by
Fehr and Caviness (1977)(see Table 6.1). Values of OVI for a given SOY
value were determined with model simulations using 1982 field data and
thus include the effects of all unknown variables, in addition to the
"true" phenology effect Increases in vegetative growth from VI to V9
were assigned sequentially increasing SOY values from 1 to 9. The
V-stage prior to flowering (V10 in 1982) and the first reproductive
stages (Rl, R2) were assigned the same SOY value. The remaining
R-stages were assigned sequentially increasing SOY values, except for
the R5 and R6 stages. Both of these stages lasted considerably longer


LIST OF TABLES
PAGE
Table 1.1. Comparison of soybean yield and profit among
various densities and timings of adult
velvetbean caterpillar influx, as simulated
with the Soybean Integrated Crop Management
model. Soybean was not irrigated in any
simulations 4
Table 2.1. Description of soybean vegetative stages 9
Table 2.2. Description of soybean reproductive-stages 10
Table 2.3. Average and range of developmental time
required for a soybean plant to develop between
stages 12
Table 2.4. Reported host plants of larval velvetbean
caterpillar 18
Table 3.1. Amount of time dedicated to behavioral
observation of adult velvetbean caterpillar in
a 1 ha soybean field at the Green Acres Research
Farm, Alachua County, FL, from 1980-82 42
Table 3.2. Estimates of the absolute density of adult
females of the velvetbean caterpillar in a
soybean field. Density was determined with
an adult trap-cage (see Chapter IV) in 1982
at the Green Acres Research Farm, Alachua
County, FL 55
Table 3.3. Mean total oviposition by adult females of the
velvetbean caterpillar reared from eggs at
constant temperatures, 14L:10D photoperiod, and
RH > 80% 58
Table 3.4. Number of unsexed, male, and female adults
of the velvetbean caterpillar observed
feeding in a soybean field at Green Acres
Research Farm, Alachua County, FL, in 1980-82 62
Table 3.5. Observational records of feeding by adult
velvetbean caterpillar during photophase at
the Green Acres Research Farm, Alachua County,
FL, from 1980-83 63
- xiii


267 -
Figure E.7. >. melinus eggs:
(A) unhatched and (B) eclosed.


173
Table C.3 (continued)
Date3
(D-M-Y)
Hour After
Sunset
Number of
Observations
of Mating
c
Observational
Time (min)
Weighted^
Observations
19-S-81
2
0
60
0.000000
24-S-81
2
1
60
0.016667
26-A-81
2
5
60
0.083333
03-S-81
2
15
60
0.250000
24-S-81
2
0
45
0.000000
05-A-80
3
4
60
0.066667
15-A-81
3
2
35
0.057143
22-A-81
3
2
32
0.062500
26-A-81
3
1
60
0.016667
29-A-81
3
2
40
0.050000
02-S-81
3
1
15
0.066667
09-S-81
3
10
42
0.238095
12-S-81
3
4
49
0.081633
17-S-81
3
4
60
0.066667'
19-S-81
3
1
18
0.055556
24-S-81
3
0
37
0.000000
26-A-82
3
0
18
0.000000
03-S-82
3
11
40
0.275000
10-S-82
3
1
38
0.026316
24-S-82
3
0
50
0.000000
05-A-80
4
1
11
0.090909
15-A-81
4
2
50
0.040000
16-A-81
4
0
10
0.000000
22-A-81
4
0
45
0.000000
23-A-81
4
0
3
0.000000
26-A-81
4
1
36
0.027778
29-A-81
4
1
35
0.028571
09-S-81
4
5
38
0.131579
12-S-81
4
2
60
0.033333


- 41
significant differences occurred between years according to the
Kruskal-Wallis Test (a = .05). Therefore, weighted observations from
different years, months, and nights were grouped by hour of occurrence.
The sample mean of the weighted observations of each hour was
calculated. These sample means were normalized, multiplied by 100 to
yield percentages, and plotted against their respective hour.
Sample means were normalized by totaling the 12 hourly sample means
and dividing each sample mean by the total. Normalization of the sample
means allowed for proportionality among the means. Percent normalized
sample means were used for ease of discussion, as opposed to the use of
normalized sample means. The standard error of each sample mean was
determined, normalized and multiplied by 100. A detailed explanation of
the quantitative technique and the raw data are presented in Appendix C.
Assumptions
To analyze the behavioral observations quantitatively, several
assumptions were made: (1) an activity had an equal chance of being
observed whether I was stationary or walking, (2) adult age did not
affect the temporal or spatial occurrence of adult activities (i.e.,
observed adults were not aged), and (3) the temporal length of
scotophase (sunset to sunrise) was the same for all nights.
Results and Discussion
Approximately 355 h were spent observing adult behavior (Table
3.1). The majority of the time (90%) was spent in the field during
July, August, and September, and more time occurred during photophase
(201 h and 19 min) than during scotophase (153 h and 13 min).
The first adult sightings in 1981 and 1982 occurred during
photophase on 3 August and 19 July, respectively. In both years, the
first adults were found in areas of the field where the
canopy was


CHAPTER III
BEHAVIORAL ECOLOGY OF ADULT VELVETBEAN CATERPILLAR
Introduction
Ethology, the study of behavior, has been slow to emerge as a
scientific discipline (Kennedy 1972, McFarland 1976). This slow
emergence seems odd, particularly with respect to pests, because pest
management mandates an understanding of pest behavior (Kennedy 1972,
Lloyd 1981, Gould 1984, Lockwood et al. 1984). Ignorance of the
behavioral ecology of pests has led to a poor understanding of
population dynamics and management (see Kennedy 1972, Stimac 1981, Burk
and Caulkins 1983, Barfield and O'Neil 1984).
Insect behavioral data, particularly for pests, is limited (Nielsen
1958, Matthews and Matthews 1978). Not surprisingly, information on the
behavioral ecology of adult velvetbean caterpillar (VBC), a major pest
of soybean in the Gulf Coast area of the United States, is sparse (see
Greene et al. 1973, Herzog and Todd 1980). The present study on the
behavioral ecology of adult VBC was initiated as part of a project to
explore the movement of adults into soybean. To examine this movement
quantitatively, a mathematical relationship needed to be established
between adult and egg densities in a soybean field (see Chapter VI). To
obtain estimates of adult and egg densities (see Chapters IV and V), and
to establish a relationship between these estimates, a number of
questions about adult behavior in the field had to be resolved: (1) Did
flight activity vary through time? (2) Did ovipositional occurrence and
frequency vary through time? (3) What environmental factors affected
- 28 -


172
Table C.3. Observation data on mating of adult velvetbean caterpillar
in a 1 ha soybean field at Green Acres Research Farm,
Alachua County, FL, 1980-82. Weighted observations are also
given.
Number of
_ a
Date
(D-M-Y)
Hour After
Sunset
Observations
of Mating
c
Observational
Time (min)
Weighted
Observations
05-A-80
1
0
49
0.000000
15-A-81
1
1
60
0.016667
19-A-81
1
0
60
0.000000
22-A-81
1
1
60
0.016667
26-A-81
1
0
60
0.000000
29-A-81
1
2
35
0.057143
02-S-81
1
0
60
0.000000
05-S-81
1
0
59
0.000000
09-S-81
1
1
49
0.020408
12-S-81
1
0
60
0.000000
17-S-81
1
1
60
0.016667
19-S-81
1
1
50
0.020000
24-S-81
1
0
60
0.000000
26-A-82
1
0
40
0.000000
03-S-82
1
3
10
0.300000
24-S-82
1
0
60
0.000000
05-A-80
2
1
60
0.016667
15-A-81
2
1
60
0.016667
19-A-81
2
0
39
0.000000
22-A-81
2
2
60
0.033333
26-A-81
2
0
30
0.000000
29-A-81
2
2
35
0.057143
02-S-81
2
1
60
0.016667
05-S-81
2
0
3
0.000000
09-S-81
2
12
28
0.428571
12-S-81
2
1
21
0.047619
17-S-81
2
4
60
0.066667


255
Spatial Occurrence: Eggs laid singly.
Similar Eggs and Differences: Other loopers, but none were observed.


- 274 -
Table F.2. Mean number of freshly-laid velvetbean caterpillar
eggs per soybean plant (1982) found in a 1 ha
soybean field at the Green Acres Research Farm,
Alachua County, FL.
Calendar
Date
Julian
Date
Sample*3
Size
c
Sample
Unit
Size
Mean No.
of Eggs/Plant
( SD)
June 21
172
70
1
.000
+
.000
25
176
70
2
.000
+
.000
28
179
70
2
.000
+
.000
July 2
183
70
2
.000
+
.000
5
186
70
2
.014
+
.014
9
190
70
2
.000
+
.000
12
193
70
2
.000
+
.000
16
197
70
2
.043
+
.042
19
200
70
2
.029
+
.028
23
204
70
2
.071
+
.096
26
207
70
2
.357
+
.523
30
211
70
2
.557
+
.801
Aug. 2
214
70
2
.857
+
1.458
6
218
70
1
.500
+
.544
9
221
70
1
.557
+
.772
13
225
50
1
.840
+
1.239
16
228
41
1
.854
+
1.478
20
232
30
1
1.100
+
1.269
23
235
30
1
1.333
+
1.709
27
239
30
1
1.400
+
1.379
30
242
30
1
1.300
+
1.784
Sept. 3
246
30
1
.633
+
.890
6
249
30
1
.733
+
.944
10
253
30
1
.933
+
1.143
13
256
30
1
.800
+
1.127
17
260
30
1
.767
+
1.194
20
263
30
1
1.833
+
2.718
24
267
30
1
.767
+
.898
27
270
30
1
.800
+
1.243
Oct. 1
274
30
1
.567
+
.817
4
277
30
1
.667
+
1.729
8
281
30
1
.067
+
.254
11
284
30
1
.133
+
.316
15
288
30
1
.000
+
.000
^ean number of soybean.plants per 0.91 m-row was 12.733.
^Sample size was the number of plants sampled,
c
Sample unit size was based on individual soybean plants; i.e.,
the sample unit size varied from one to two plants.


108 -
20 ha) occurred in the general area of the study and supported
populations of VBC.
Calibration of Adult Density
Linear regression was used to examine the relationship between the
total number of moths captured in the BLT and the total number of moths
in the field determined from trap-cage sampling data (see Appendix D,
Table D.4). Significant relationships were found for females, males,
and adults (females and males), although the proportion of the total
variation, as explained by the BLT catch, is low for all three models
(see Table 4.7). This low explanation is not surprising because BLT
catch fluctuates nightly (see Fig. 4.2) and can not be predicted very
well from weather variables (see Tables 4.5 and 4.6). Also, the models
in Table 4.7 are not realistic biologically. Based on positive
intercept values, these models demonstrate that moths are caught in the
field before they are caught in the BLT. Sample data do not support
this demonstration, as adults were caught in the BLT before they were
caught in the field. Smoothing* the BLT data provides more realistic
regression equations (i.e., negative intercepts) and increases r2 ca.
20% (see Table 4.8).
Conclusions
This study represents the first quantitative assessment of adult
VBC movement within a soybean field. Adult appearance (or density) in
the field was measured with a blacklight trap (BLT) and coincided with
the appearance of eggs, demonstrating that adult density can be
monitored with a BLT and that a BLT is sensitive to adult capture at low
*Data were smoothed with a nonlinear data smoothing algorithm (3RSSH,
twice) based on running medians (see Velleman 1980, Ryan et al. 1982).


162 -
is a series of white dots that run parallel to the outer wing-margin
[Fig. B.1(B and D), letter d].
Sexual Dimorphism
Males have tufts of long setae that are present on the femora of
prothoracic legs and the tibiae of the metathoracic legs [Fig. B.l(B),
letter e]. These long setae are absent on female legs [Fig. B.l(D)]
(Anonymous 1974).
Mocis latipes (Guenee)
Wing Span
35-40 mm (Forbes 1954).
Dorsal Wing Surface
Forewing: Wing coloration is light gray, light brown, or dull
brownish-red (Hampson 1913, Forbes 1954). Wing pattern is shaded, and
wing-mark colorations are brown, gray, and grayish-brown [Fig. B.2(A and
C)]. The postmedial line is nearly parallel to the outer wing-margin
and is essentially straight, except for a slight bend just below the
costa [Fig. B.2(A and C), letter a]. The reniform spot is generally
evident, vaguely circular, and usually touches the subreinform spot
[Fig. B.2(A and C), letter b]. The subreniform spot is usually
distinct, usually circular, and may open onto the postmedial line [Fig.
B.2(A and C), letter c]. When viewed at the same time, the reniform and
subreniform spot resemble a figure eight [Fig. B.2(A and C), letters b
and c].
Hindwing: Wing coloration is light gray, light brown, or grayish-
brown [Fig. B.2(A and C)](Hampson 1913 and Forbes 1954). In general,
wing marks are vague ot absent. The postmedial line is usually present,
usually vague, and nearly parallel to the outer wing-margin [Fig. B.2(A
and C), letter d].


APPENDIX D
ADULT DENSITY AND PHYSICAL VARIABLE DATA,
AND MATHEMATICAL DESCRIPTIONS OF PHYSICAL VARIABLES


259 -
Heliothis zea (Boddie)
Common Names:
Bollworm, Corn Earworm, Tomato
Fruitworm.
Heliothis virescens (Fabricius)
Common Name:
Tobacco Budworm.
Note: The eggs of these two species were indistinguishable.
Family:
Noctuidae.
Egg Development,
Color-Changes and Types:
Freshly Laid
Creamy white, yellowish white, off
white, whitish [Fig. E.5(A)].
Middle Aged
Same as freshly laid but with colored
band around equator. Band is vaguely
defined and reddish brown, brownish
brown or brown [Fig. E.5(B)].
Old (Pre-Eclosion)
Creamy white with black larval head
capsule.
Parasitized
Black [Fig. E.5(C and D)].
Parasitoid Emerged
Black or grayish with hole in egg [Fig.
E. 5(E) ].
Egg Shape: Top View
Circular.
Side View
Barrel shaped.
Ridge Number:
x SD = 24.7 1.5, range 21-28, n =
18.
Ridge Morphology:
Distinct, easy to count.


115
an individual oviposition cage and supplied with an ovipositional
substrate of green paper* (see Moscardi 1979). Eggs were collected at
0.5 h after darkness by removal of the ovipositional substrate.
To determine temperature-dependent egg development, all collected
eggs (from colony and wild adults) were maintained in growth chambers at
a series of constant temperatures, 14L:10D photoperiod, and > 90% RH.
In 1980-82, eggs were kept in Percival Growth Chambers (Model I-35LL)
and, in 1983-84, in walk-in chambers (2.2 x 2.5 x 2.3 m). Egg
development was studied at 4.0, 6.4, 10.4, 14.8, 19.5 and 26.7 1C
(1980-81); at 23.9 and 26.7 1C (1982); at 26.7 1C (1983); and at
18.3, 21.1, 23.9, 26.7, 29.9, and 32.2 1C (1984). Egg coloration
and development were monitored with a 70X dissecting microscope at
variable time intervals (1980-81) and at hourly intervals (1982-84).
Field Sampling of Velvetbean Caterpillar Eggs
Eggs were sampled (1981-1982) twice a week in a 1 ha soybean field
(cv. Bragg)** at the University of Florida's Green Acres Research Farm
(ca. 22.5 km west of Gainesville, FL, Alachua County). Plants were
selected with simple random allocation, cut at soil line, removed from
the field and placed in a walk-in growth chamber (2 1C); plant stems
were placed in water to delay leaf wilt. In 1981, 70 randomly selected
plants were sampled on each sample date during the hour just before and
after sunset***. Sample unit size equaled one plant. In 1982, 30 to
*Springhill Bond/Offset International Paper Co., color green, 10M
weight, long grain.
**See Appendix A for agronomic practices and soybean phenological
stages.
***Oviposition rate during these times is known to be extremely low (see
Chapter III).


- 268 -
Unknown Species
Common Name:
Unknown.
Family:
Noctuidae (?).
Egg Development,
Color-Changes and Types:
Freshly Laid
.. Whitish, grayish white, yellowish white
[Fig. E.8(A)].
Middle Aged
. Same as freshly laid but with reddish-
brown band around egg and reddish-brown
splotch under the microphylar area
[Fig. E.8(B)].
Old (Pre-Eclosion)
.. Unknown.
Parasitized
.. Black [Fig. E.8(C)].
Egg Shape: Top View
.. Circular.
Side View
.. Dome like.
Ridge Number:
26, n = 1.
Ridge Morphology:
Distinct, easy to count.
Micropylar Area:
Nipple like.
Spatial Occurrence:
Eggs laid singly.
Similar Eggs and Differences:
Unknown.


- 54 -
The temporal occurrence of oviposition in the field may be due to
the selective pressures of egg predators and parasites. Eggs are mint
green when laid (see below and Chapter V) and are easy to see on
soybean. As eggs age, they develop a speckling pattern (see below and
Chapter V) and are extremely difficult to see on a plant (i.e., speckled
eggs are cryptic). The occurrence of this speckling pattern is
temperature dependent (see Chapter V). Eggs laid during early
scotophase speckle at or just after sunrise (see Chapter V) and probably
are difficult for predators to see. Eggs laid during late scotophase
are still mint green after sunrise, are easy to see, and probably are
exposed to more predation. Females that oviposit in early scotophase
should demonstrate a higher reproductive fitness over females that lay
eggs in late scotophase.
Oviposition was difficult to observe. Only 121 sightings were made
during the 153 h 13 min of scotophase observation (see Appendix C, Table
C.5). Female density may have affected the viewing of oviposition. In
1982, an estimate of female absolute density in the field was obtained
at weekly intervals with an adult trap-cage (Table 3.2, see also Chapter
IV). Estimates of female density were highest from August 26 to
September 23. Interestingly, 61 of 73 ovipositional sightings (81%)
were made at this time with an investment of only 41% of total
observation time (1764 of 4348 min)(see Appendix C, Table C.5).
Obviously, a productive time period to view oviposition occurred when
total female density was greater than ca. 764 individuals.
Concentration of more observation time during this time period may have
generated more sightings.
Flight speed of ovipositing females was moderate and wing beat was
flutter-like. The distance between ovipositional sites varied from ca.


CHAPTER II
LITERATURE REVIEW
Introduction
Accomplishment of present objectives (see Chapter I) demanded that
soybean, velvetbean caterpillar (VBC), and the environment of both be
viewed as interacting components of a system. Velvetbean caterpillar
use soybean as an adult ovipositional substrate (see Greene et al.
1973), a larval food source (see Moscardi et al. 1981a), and an adult
habitat (see Herzog and Todd 1980). Soybean foliage and yield decrease
with VBC larval consumption (Strayer 1973), and temperature affects the
growth of both species (see Parker and Borthwick 1943, Johnson et al.
1983). Obviously, to view soybean and VBC as components of a system
requires an understanding of the ecology of each species. The objective
of this chapter is to review briefly the ecology of soybean and VBC,
their relevant interactions, and environmental factors that affect both.
Soybean Ecology
Soybean, Glycine max (L.) Merrill, became a domesticated species
probably in the North China Plains around the 11th century (Hymowitz
1970). The progenitor species apparently was G. ussuriensis Regel and
Maack (Morse et al. 1949). Polhill and Raven (1981) provide part of the
hierarchical classification for soybean as follows:
Order: Rosales
Family: Leguminosae
Subfamily: Papilionoidae
- 6 -


Table 2.4 (continued)
Family
Leguminosae
Scientific Name
Phaseolus vulgaris var.
Pisum sativum L.
Pisum sp.
Pueraria lobata Willd.
Pueraria phaseoloides (Roxb)
Pueraria thumbergiana
(Siebold and Zucc.) Benth
Rhynchosia minima L.
Robinia pseudoacacia L.
Sesbania emerus (Aubl.)
Britton and Wilson
Sesbania exaltata (Raf.)
V.L. Cory
Sesbania macrocarpa Muhlenb.
ex Raf.
Common Name
Reference
Bush Bean
humilis Alef.
Ford et al. (1975)
English Pea
DPIb
Field Pea
DPIb
Kudzu
Buschman et al. (1977)
Tropical Kudzu
Benth
Ford et al. (1975)
Kudzu Vine
Watson (1916a)
Least Rhynchosia
Buschman et al. (1977)
Black Locust
Ellisor (1942)
Long Pod
DPIb
Sesbania
Tietz (1972)
Coffee Weed
Hinds and Osterberger (1931)


- 34 -
(usually with claspers extended), and landing or flying away. In the
field bioassay, male attractiveness to three females in a trap commenced
ca. 1 h after sunset and remained fairly uniform throughout the night.
Pheromone, extracted from females 4 h and 6 h after sunset, was more
attractive to males than pheromone extracted 9 h and 6 h before dark, at
sunset, or 2 h and 9 h after sunset. A significant decrease in male
capture was noted with increasing age of females. Also, mated females
were less attractive to males. The female sex-pheromone was identified
as a blend of (Z,Z,Z)-3,6,9-eicosatriene and (Z,Z,Z)-3,6,9-
heneicosatriene in a blended ratio of ca 5:3, respectively (Heath et al.
1983). Synthesized pheromone elicited responses by adult males
equivalent to those elicited by females in both laboratory bioassays and
field-trapping experiments (Heath et al. 1983).
Oviposition
Early reports of oviposition were not quantified. Watson (1916a)
noted most eggs were laid singly on the bottom leaf-surface of
velvetbean, but some were laid on the upper leaf-surface, petiole, and
stem. He also reported oviposition on the tender shoots, the underside
of the leaves (Watson 1915), mostly on the bottom of younger leaves
(Watson 1916b), and mostly on the bottom of mature leaves (Watson
1916c). Watson apparently was confused as to where the majority of eggs
were laid. Watson (1921, p. 2) further reported that, "the moths are
shade-loving creatures and collect under the vines in the densest shade
and there lay their eggs."
Douglas (1930) indicated that eggs were deposited singly on the
underside of soybean leaflets and sometimes on the upper leaflet
surface. Females often laid one egg per plant, sometimes several.
Hinds (1930) reported that eggs were deposited singly on soybean,


- 9 -
Table 2.1. Description of soybean vegetative stages (Fehr and Caviness
1977).
Stage
Stage Title
Description
VE
Emergence
Cotyledons above the soil surface.
VC
Cotyledon
Unifoliolate leaves unrolled sufficiently
so that leaf edges are not touching.
VI
First-Node
Fully developed leaves at unifoliolate nodes.
V2
Second-Node
Fully developed trifoliolate leaf at node
above the unifoliolate nodes.
V3
Third-Node
Three nodes on the main stem with fully
developed leaves beginning with the
unifoliolate nodes.
V (n)
nth-Node
The number of nodes on the main stem is equal
to 'n', beginning with the unifoliate nodes.


- 4 -
Table 1.1. Comparison of soybean yield and profit among
various densities and timings of adult velvetbean
caterpillar influx, as simulated with the Soybean
Integrated Crop Management model (modified from
Wilkerson et al. 1982). Soybean was not irrigated
in any simulations.
VBC3
Density
Influx^
Timing
Yield
(Kg/ha)
Profit
($/ha)
Low
Normal
1896.18
169.21
Average
Normal
1493.02
65.70
High
Normal
403.97
-214.26
Average
Early
110.32
-289.63
Average
Normal
1493.02
65.70
Average
Late
1931.86
178.43
None
None
2177.57
241.61
aHigh = +0
^Early was
.5 Average;
30 days prior
Low = -0.5 Average.
to normal and late was
30 days later
than normal.


Table D.3 (continued)
Total numbers were smoothed with a nonlinear data-smoothing algorithm (3RSSH, twice) based on running
medians (see Velleman 1980, Ryan et al. 1982).
^Weighted Total // = (Total // Smoothed #)/ (Smoothed #).


Table C.8 (continued)
Date3
(D-M-Y)
b
Hour
MaleC
Agg
Maled
OAgg
Male*
All
_ f
Female
Adult8
MFAh
Agg
MFA1
OAgg
Tine
03-S-82
1
0
2
2
0
,
3
3
10
24-S-82
1
0
4
4
0
5
9
9
60
05-A-80
2
0
0
0
0
4
4
4
60
Ol-A-81
2
0
0
0
0
0
0
0
60
05-A-81
2
0
0
0
0
0
0
0
IS
12-A-8I
2
0
4
4
9
0
13
13
54
15-A-81
2
0
1
1
2
4
7
7
60
19-A-8I
2
0
0
0
0
0
0
0
39
22-A-8I
2
0
0
0
2
0
2
2
60
26-A-8I
2
0
0
0
0
0
0
0
30
29-A-81
2
0
0
0
0
0
0
0
35
02-S-81
2
0
0
0
4
0
4
4
60
05-S-81
2
0
0
0
0
0
0
0
3
09-S-81
2
0
0
0
0
0
0
0
28
12-S-81
2
0
0
0
0
0
0
0
21
17-S-81
2
22
0
22
0
0
22
0
60
19-S-8I
2
9
7
16
0
0
16
7
60
24-S-81
2
0
0
0
0
0
0
0
60
26-A-82
2
0
6
6
3
0
9
9
60
Weight
3
Weight
4
Weight
5
Weight*1
1
Weight *
2
Weight** Weight**
6 7
0.000000
0.200000
0.200000
0.000000
0.100000
0.300000
0.300000
0.000000
0.066667
0.066667
0.000000
0.083333
0.150000
0.150000
0.000000
0.000000
0.000000
0.000000
0.066667
0.066667
0.066667
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.074074
0.074074
0.166667
0.000000
0.240741
0.240741
0.000000
0.016667
0.016667
0.033333
0.066667
0.116667
0.116667
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.033333
0.000000
0.033333
0.033333
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.066667
0.000000
0.066667
0.066667
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.366667
0.000000
0.366667
0.000000
0.000000
0.366667
0.000000
0.150000
0. 1 16667
0.266667
0.000000
0.000000
0.266667
0.116667
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.100000
0.100000
0.050000
0.000000
0.150000
0.150000
186


214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
- 283 -
(continued)
FBLT
LB05
EEGG
UB05
SOY
6
3.66
5.46
7.26
11
4

11
1


11
10


11
2
4.17
6.37
8.57
12
3


12
10


12
16
4.47
7.09
9.71
12
21


12
15


12
10


12
11
6.77
10.70
14.62
12
15


12
20


12
31
6.13
10.87
15.61
13
51

13
37


13
48


13
37
8.23
14.01
19.79
14
24


14
19


14
24
9.19
16.97
24.76
14
28


14
26


14
19


14
75
11.54
17.83
24.11
15
43

15
64

15
106
8.42
16.55
24.68
15
75


15
97


15
75


15
75
4.01
8.06
12.12
15
50


15
53


15
62
5.03
9.34
13.64
15
41


15
72


15
52

15
141
6.68
11.88
17.09
15
81

15
43

15
33
5.05
10.19
15.32
16
57

16
51

16


CHAPTER VI
A MODEL OF VELVETBEAN CATERPILLAR ADULT
AND EGG POPULATIONS
Introduction
Crop/plant models can be used "to simulate the dynamics of a crop
and pests in a single field so that decisions can be made regarding pest
management and other production practices for that field" (Stimac and
O'Neil 1985, p. 323). One such crop/pest model is the Soybean
Integrated Crop Management (SICM) model (Wilkerson et al. 1982, 1983).
This model is composed of an aggregate of submodels that describe the
physiology of soybean growth in the presence or absence of abiotic and
biotic stresses. The model is designed to allow the user to study
various crop production and pest management strategies at the field
level for different weather patterns, cultural practices, and insect
pest scenarios.
One of the SICM submodels represents the population dynamics of
velvetbean caterpillar (VBC), a major defoliating pest of soybean
(Herzog and Todd 1980, Wilkerson et al. in press). Simulations with
SICM and the VBC submodel demonstrate that changes in the pattern
(timing and magnitude) of adult VBC influx and subsequent oviposition,
result in dramatic differences in soybean yield and net profit (see
Table 1.1). Adult and egg densities in the model were determined from
estimated larval densities. Larval densities at time "t" were used to
determine egg and adult densities at time "t-1" by calculating the adult
and egg densities required to produce the measured larval densities at
127


11
are approximately the same size, and their resultant canopies are
thought to have poorer light-distribution characteristics.
Indeterminate cultivars continue to grow vegetatively during flowering,
and early pod, and seed development. Flowering begins when these
cultivars have reached about half their height and continues as the
plant grows taller. For determinate varieties, plants reach full height
at flowering and flowers emerge at approximately the same time from all
nodes (Fehr et al. 1971, Shibles et al. 1975, Fehr and Caviness 1977).
Fehr and Caviness (1977) provide average and range estimates of
soybean development between stages (see Table 2.3). The average number
of days for complete development is 125, with a range of 74 to 218. The
large range in developmental time results from effects of temperature,
variety, photoperiod, and water stress (Doss et al. 1974, Fehr and
Caviness 1977) The major factor that influences vegetative growth is
temperature. Seedling emergence and leaf development are retarded by
low temperatures and enhanced by high temperatures (Fehr and Caviness
1977).
Soybean leaves exhibit Calvin-cycle photosynthesis, but stems and
pods also contribute to carbon dioxide uptake (Weiss 1983). Leaf area
production begins slowly, then increases rapidly and increases almost
linearly during mid-vegetative growth. Maximum leaf-area index (LAI*)
values of five to eight can be achieved by late flowering. During seed
filling and after flowering, LAI declines progressively by abscission of
lower leaves (Shibles et al. 1975).
*Leaf Area Index (LAI) is "the surface area of leaves per unit surface
area of ground" (Lewis 1977, p. 87).


- 240 -
photographed with the following Olympus equipment (except where noted)
0M-2 35mm SLR Camera, Auto Bellows, Macro Lens (1:35, f = 20mm, 16 to
3.5 f stop), three Electronic Flash T32's, Control Box, Emerson
Micromanipulator, and Kodachrome64 slide film (KR 135-36).
Results and Discussion
A pictorial key to egg identification by species is presented on
the following pages.


PAGE
Table 3.6. Number of unsexed adults of the velvetbean
caterpillar observed feeding in a soybean
field at Green Acres Research Farm, Alachua
County, FL, in 1980-82. Description of food
site and host provided
Table 3.7. Number of male and female adults of the
velvetbean caterpillar feeding in a soybean
field at Green Acres Research Farm, Alachua
County, FL, from 1980-82. Description of food
site and host provided
Table 3.8. Number of adult males of the velvetbean
caterpillar feeding in a soybean field at
Green Acres Research Farm, Alachua County,
FL, from 1980-82. Also, number of males per
aggregate, number of aggregates, and
description of food site are provided
Table 3.9. Records of spider predation on adult velvetbean
caterpillar (VBC) from 1980-83 at Green Acres
Research Farm, Alachua County, FL, in a 1 ha
soybean field. All records occurred during
scotophase
Table 4.1. Description of physical variables monitored
in Alachua County, FL, in 1981-82
Table 4.2. Amount of rainfall recorded at the number 3
WSW climatological station of the University
of Florida, Gainesville, FL, Alachua County.
Cooperative climatological station of the
Agronomy Department and NOAA
Table 4.3. The mean number (SE) of spermatophores per
female per reproductive category of adult
velvetbean caterpillar. Females were caught in
a blacklight trap during 1981 at the Green
Acres Research Farm, Alachua County, FL
Table 4.4. Mean seasonal sex ratios of adult velvetbean
caterpillar caught in blacklight traps and
an adult trap-cage in a 1 ha soybean field
at the Green Acres Research Farm, Alachua
County, FL
Table 4.5. Regression equations of physical variables and
total numbers of males, females, and adults of
the velvetbean caterpillar. Moths were caught
in a blacklight trap at the Green Acres
Research Farm, Alachua County, FL
65
66
67
75
86
91
96
104
106
- xiv -


- 91 -
Table 4.2. Amount of rainfall recorded at the number 3 WSW
climatological station of the University of Florida,
Gainesville, FL, Alachua County. Cooperative
climatological station of the Agronomy Department and
NOAA.
Month
1980
Rainfall (cm)
1981
1982
Normal3
Rainfall (cm)
July
22.00
7.39
17.17
20.40
August
8.08
12.65
15.70
20.96
Total
30.08
20.04
32.87
41.36
Normal is 70 year mean.


Figure 4.1. Trap-cage used to collect adult velvetbean caterpillar in a 1 ha soybean field during
1982 at the University of Florida's Green Acres Research Farm, Alachua County, FL.


256 -
Figure E.4. P. includens eggs: (A) freshly laid, (B) old or
pre-eclosion, (C) parasitized, (D)-(G) parasitoid emerging,
and (H) parasitoid.


- 45 -
Flight activity did not appear to be affected by moon phase,
moonlight, humidity, dew, wind speed or wind direction. During light
rainfall, flight activity was unaffected but, during intermediate to
severe rainfall, flight activity was reduced. If moderate or severe
rainfall stopped between sunset and ca. 4.5 h post-sunset, flight
activity resumed. If rain stopped after ca. 4.5 h post-sunset, flight
activity was negligible.
Flight activity was affected by temperature. On 19 September 1981,
ambient temperature decreased from 17.7C at 2000 to 11.9C at 2230,
when flight activity stopped. Twenty-three adults (11 males and 12
females) were picked up or touched. None of these moths were able to
fly but some slowly flapped their wings once or twice. Thus, 11.9C was
designated as the lower threshold-temperature for flight activity.
In general, present observations of flight activity agree with
previous observations of feral adults (see Watson 1915, 1916a, 1916b,
Douglas 1930, Ellisor 1942, Greene et al. 1973, Gutierrez and Pulido
1978), but do not agree with observations of colony adults (see Leppla
et al. 1979, Wales 1983). Leppla et al. (1979) found a high frequency
of flight during photophase of the first six days for paired adults and
Wales (1983) was unable to resolve hourly patterns of flight frequency
during scotophase. Results from both studies contrast sharply with
present findings. Differences among the present study and those of
Leppla et al. (1979), and Wales (1983) may be an artifact of adult
colonization. Colonized adults apparently behave differently than wild
adults.
Mating
Of the five stages in the courtship sequence reported by Greene et
al. (1973), four were observed in the field: pheromone release, male


123
Table 5.3. The total number of degree-hours accumulated
between sunset (onset of oviposition) and
plant sampling during each sample date in
1981 and 1982. Mean number of degree-hours
required for speckling to occur in VBC eggs
is 153.27.
1981
1982
Julian
Accumulated
Julian
Accumulated
Date
Degree-Hours
Date
Degree-Hours
204
124.1
186
96.4
208
161.3a
190
102.5
211
123.8
193
106.7
215
144.3
197
123.9
218
146.5
200
125.8
222
144.3
204
123.3
225
141.3
207
138.3
229
155.5a
211
131.1
232
140.8
214
144.3
236
143.8
218
93.6
239
140.3
221
118.3
243
128.4
225
112.6
246
132.8
228
117.6
250
113.8
232
107.5
257
11.5
235
125.8
239
111.4
242
105.2
246
118.0
249
107.9
253
100.3
256
110.5
260
109.1
263
116.4
267
91.9
270
75.0
274
85.0
277
118.9
281
104.3
284
115.0
288
23.2
a
Accumulated degree-hours
exceeded
153.27.


- 35 -
scattered about the plant and found on leaves and stems. On leaves, the
midrib was preferred because the pilosity was heaviest. Oviposition was
observed by Hinds (1930) at dusk and assumed to continue into the night.
Observations by Ellisor (1942) indicated the following: (1) oviposition
on soybean began in late afternoon and extended through the night, (2)
eggs were laid singly and many eggs were laid on each plant, (3) eggs
were found on the stems, seed pods, and leaves, and (4) eggs were found
often on the midrib and veins of a leaflet underside.
The only detailed observations of oviposition have been presented
by Greene et al. (1973). Wild adults in soybean were observed in a 1.83
x 1.83 x 3.66 m cage during scotophase over a seven-day period.
Observations started at sunset (ca. 2000) and stopped at 0300, except
for the first night when observations stopped at 0800. Females laid
eggs singly, but two or three eggs were laid occasionally at a given
site with the eggs ca. 1 cm apart. Females fluttered quickly between
ovipositional sites and deposited an egg in 2-60 sec. Frequently,
females exhibited ovipositional behavior but no eggs were laid. Eggs
were deposited on stems, pods, and leaf bottoms.
"Oviposition was closely observed several times and consisted of
the moth first clasping part of the plant with her feet, then arching
the tip of her abdomen ventrally. When the plant surface was touched by
her abdomen, it expanded; the conjunctiva anterior of her ovipositor
became visible, and an egg was deposited. The egg was usually placed
between the plant hairs close to the surface, and adhered tightly to the
plant. Rain or dew did not remove the eggs, and they were nearly
impossible to remove from the leaf with a camel's hair brush" (Greene et
al. 1973, p. 1115).


- 61
was highest along the main vein and less dense along the secondary
veins. Pulvini were covered in a thick "carpet" of trichomes and
petioles had trichomes that occurred in longitudinal rows. Both Hinds
(1930) and Ellisor (1942) noted an ovipositional preference for areas of
high trichome density.
Feeding
More individuals were observed feeding than for any other activity.
A total of 458 individuals were sighted: 268 males, 129 females, and 61
unsexed adults (Table 3.4). Unsexed adults flew away before a positive
sexual identification could be made. Feeding occurred predominately at
night, when 448 of the moths (or 98%) were observed (Table 3.4).
When feeding, the proboscis was extended, touched the food source,
and was maneuvered across the food source surface. Except for flowers,
all moths were observed to feed on moist surfaces. This moisture was
either rain water, dew, plant-guttated water, or plant exudates. When
feeding at a flower, a moth would probe the flower with its proboscis.
The attainment of nectar or pollen was not assessed. No adults were
observed to feed at soybean flowers and none of the food sources were
chemically analyzed.
Overall, feeding was the easiest behavioral activity to observe.
At night, adults were easy to approach and observe. Individuals
"rested" on an available substrate while feeding, as opposed to flying.
During the day, adults were more difficult to approach and observe. On
six occasions, moths were observed feeding at flowers (Table 3.5).
These moths hovered in flight while feeding, were in the open, and were
easy to see. When approached from ca. 1.5 m moths stopped feeding, flew
a short distance and "hid" among weeds. Apparently, adults can see very


- 233 -
Table D.8 (continued)
Vapor
Press.
Calendar
Date
Julian
Date
Flight
Temp. (C)
Deficit
(mm Hg)
Aug. 23
235
11.29
.122
24
236
11.84
.266
25
237
11.48
.000
26
238
11.79
.022
27
239
10.68
.000
28
240
10.42
1.262
29
241
11.18
1.341
30
242
9.21
.559
31
243
9.56
.677
Sept. 1
244
8.76
.954
2
245
12.14
1.204
3
246
12.75
1.381
4
247
11.08
1.030
5
248
10.27
.000
6
249
9.67
.219
7
250
9.92
.000
8
251
11.08
.000
9
252
11.64
.000
10
253
10.07
.000
11
254
11.43
.000
12
255
10.27
.000
13
256
9.87
.631
14
257
8.66
.058
15
258
10.07
.000
16
259
11.18
.249
17
260
9.31
.326
18
261
10.07
.491
19
262
9.56
.000
20
263
10.51
.228
Moonlight Barometric
Intensity
Rainfall
Press. (MB)
.0054
.0000
1018.63
.0207
.0000
1017.89
.0139
.0000
1015.41
.0000
.0000
1015.01
.0297
.0000
1015.67
.0530
.0061
1016.65
.1737
.0000
1020.18
.2952
.0000
1021.21
.4234
.0000
1020.16
.6237
.0000
1017.54
.6175
.0000
1015.25
.7100
.0000
1014.61
.6916
.0000
1015.76
.3135
.0000
1013.71
.3109
.0000
1018.80
.1276
.0025
1017.62
.0818
.0000
1016.82
.0309
.0000
1016.02
.0447
.0000
1015.74
.0389
.0000
1017.13
.0140
.0000
1019.45
.0062
.0000
1013.92
.0036
.0000
1016.52
.0009
.0000
1014.05
.0000
.0000
1013.59
.0000
.0000
1014.29
.0000
.0043
1013.26
.0001
.0000
1013.44
.0016
.0000
1014.13


a
Table 3.6. Number of unsexed adults of the velvetbean caterpillar observed feeding in a soybean
field at Green Acres Research Farm, Alachua County, FL, in 1980-82. Description of food
site and host provided.
No. of Unsexed^
Adults Feeding
FoodC
Site
Food Host
Common Name
Scientific Name
Family
4
Flower
Horse Mint
Monarda puntata L.
Labiatae
43
Raceme
Bahiagrass
Paspalum notatum Flugge
Gramineae
2
Raceme
Unknown Grass

Gramineae
1
Flower, Unopened
Florida Pusley
Richardia scabra L.
Rubiaceae
6
Flower, Outside
Hairy Indigo
Indigofera hirsuta L.
Leguminosae
5
Flower
Hairy Indigo
Indigofera hirsuta L.
Leguminosae
Unsexed adults flew out of sight before a positive sexual identification could be made.
bTotal = 61.
c
Adults fed at the surfaces of plant structures or in flowers.


- 264 -
Figure E.6. U. proteus eggs: (A and B) freshly laid, (C) old or
pre-eclosion, and (D) eclosed.


Table D.7 (continued)
Vapor
Press.
Calendar
Date
Julian
Date
Flight
Temp. (C)
Deficit
(mm Hg)
Aug. 20
232
10.93
.813
21
233
10.93
.858
22
234
11.58
1.396
23
235
12.04
2.473
24
236
10.57
1.671
25
237
7.95
1.248
26
238
10.22
.980
27
239
10.78
.675
28
240
10.68
.866
29
241
10.37
.520
30
242
10.57
.426
31
243
10.52
1.251
Sept. 1
244
10.83
1.654
2
245
9.97
2.021
3
246
10.73
1.600
4
247
11.74
2.092
5
248
11.99
1.414
Moonlight
Intensity
.0125
.0228
.0408
.0154
.0216
.0057
.0000
.0000
.0000
.0000
.0000
.0026
.0021
.0063
.0079
.0167
.0000
Wind
Speed Wind Barometric
(m/s) Direction Rainfall Press. (MB)
.701
163.6
.0000
1013.97
.710
139.4
.0000
1014.85
1.693
167.4
.0003
1017.34
.950
95.8
.0000
1017.16
.801
116.1
.0000
1017.66
.597
107.4
.0000
1016.46
1.307
135.6
.0000
1015.57
1.556
169.5
.0467
1016.89
1.161
165.1
.0000
1018.85
.300
141.4
.0057
1016.48
.137
139.9
.0000
1014.74
.541
117.3
.0000
1013.60
.328
129.5
.0000
1012.95
.207
126.5
.0000
1014.32
. 101
118.5
.0000
1014.65
.259
117.9
.0000
1014.71
.651
130.7
.0000
1015.35
228


145
desirable model behavior. These modifications could be made with any or
all of the following functions: (1) total female number, (2) mated
female number, (3) mated female mortality, and (4) ovipositional rate.
Those functions that describe total female number and ovipositional rate
would appear to be the most important functions to modify, as
simulations revealed that the model was sensitive to changes in the
values of these functions. Experimental evidence of a variable
ovipositional rate should be gathered and quantified, particularly with
reference to VPD. Also, further examination of the function that
describes total female number may reveal that the mathematical
description of this function could be described more adequately with a
mechanistic representation. Collection of additional adult density
estimates with the BLT and the adult trap-cage would provide a more
complete data base for determination of the mathematical form of this
function and for determination of what variables might affect this
function. Use of a constant or a function to describe the proportion of
mated females and mated female mortality, based on field collected data,
might provide more adequate model behavior.
The present model has limited applicability as it is a site-
specific model based on two years of data; however, incorporation of
this model into the VBC dynamics model would allow for larval densities
to be predicted with BLT catch. Ultimately, the prediction of larval
densities with BLT catch could be used to eliminate scouting for larvae
in fields until adult populations reach some predetermined density. The
acquisition of additional data on adult and egg numbers from different
years would allow for model analysis, improvements and refinements.
Overall, the establishment of the quantitative relationship between


CHAPTER I
INTRODUCTION
Soybean, Glycine max (L.) Merrill, is presently the most important
grain legume in the world and is used for food, medicine, and oil (Weiss
1983). Farmers in the United States produce ca. 56% of the world's
soybean or ca. 43 million metric tons (FAO 1984). Thirty-seven percent
of the soybean production in the United States occurs in the southeast,
and this percentage is expected to increase considerably by the year
2000 because of an increasing worldwide demand (Turnipseed et al. 1979).
Soybean production in the southeastern United States is plagued by
numerous pest problems (e.g., insects, weeds, nematodes, and plant
pathogens), and these problems are expected to escalate because of the
increasing acreage being devoted to this crop (Turnipseed et al. 1979).
One way to explore alternative strategies for the management of
soybean pests is through the utilization of crop/pest models, where the
models are mathematical representations (computer simulated) of the
interactions between the crop and its principal pest-species (Stimac and
O'Neil 1985). Crop/pest models can be used "to simulate the dynamics of
a crop and pests in a single field so that decisions can be made
regarding pest management and other production practices for that field.
The objective of building a crop/pest model is to describe the dynamics
of the crop and pests in the context of the environment in which they
coexist. The environment includes many factors influencing the growth
of the crop and pest populations: weather inputs, such as temperature,
1


- 3 -
fields (see Herzog and Todd 1980, Wilkerson et al. 1983). Furthermore,
egg density data are essential for model construction because the mere
presence of adults does not connote the presence of eggs and the
resultant defoliating larvae. The absence of VBC immigration data is
not surprising because the control recommendations for most pests are
designed without consideration for quantitative estimates of pest
immigration (see Barfield and O'Neil 1984).
To assess immigration in the current version of the VBC Submodel,
adult and egg densities were estimated from larval densities (Stimac,*
personal communication). Changes in the density and timing of adult
influx resulted in notable differences in soybean yield and grower
profit (see Table 1.1). With density varied and timing of influx held
constant, profit per hectare varied from $169.21 (low density) to
-$214.26 (high density). With influx timing varied and density held
constant, profit per hectare varied from $178.43 (late influx) to
-$289.63 (early influx). Without VBC (i.e., a simulation control),
profit per hectare was $241.61, the highest of all the simulations.
Clearly, the need to investigate VBC immigration into soybean was
delineated through the use of these simulations.
Present research goals were to (1) investigate the immigration of
VBC adults into soybean, (2) explore the interactions between soybean
phenology and VBC adults, and (3) quantify adult and egg densities in
soybean. These goals were accomplished by the construction of an adult
*J. L. Stimac, Associate Professor, Department of Entomology and
Nematology, University of Florida, Gainesville, FL 32611. Larval
densities at time "t" were used to determine egg and adult densities at
time "t-1" by calculating the densities of adults and eggs required to
produce the known larval densities. Mortality values of adults and
eggs were used in these calculations.


Introduction
Egg density data were required to construct a model of adult
velvetbean caterpillar (VBC) oviposition in soybean (see Chapters V and
VI). Accurate estimation of VBC egg density depended on proper
identification of Lepidoptera eggs collected during sampling.
Mis-identification of VBC eggs could have led to inflated egg density
estimates. The present study was initiated to identify and describe
some Lepidoptera eggs found on soybean.
Materials and Methods
From 1980-82, the development and color changes of eggs of several
lepidoptera species were documented. Eggs were collected with four
different techniques: (1) colony adults* were allowed to oviposit on
soybean in the lab; (2) wild adults were collected from soybean and
allowed to oviposit on soybean in the lab; (3) wild adults were observed
to oviposit in the field; and (4) eggs were found on soybean and reared
to adults** (see Table E.l). All wild adults and eggs were obtained
from a 1 ha soybean field (cv. Bragg) at the University of Florida's
Green Acres Research Farm, Alachua County, FL (see Appendix A for
agronomic practices). All adults and eggs were maintained in the lab in
Percival Growth Chambers (Model I-35LL) at 26.7 1C, > 80% RH, and
14L:10D photoperiod and in the presence of a 7.5 w nightlight (General
Electric, 7.5 S/CW). Egg development and coloration were monitored with
a 70X dissecting microscope at variable time intervals. All eggs were
*Colony adults were obtained from Dr. N. C. Leppla, Research Scientist,
USDA Insect Attractants, Behavior, and Basic Biology Research
Laboratory, Gainesville, FL 32604.
**Eggs collected with the fourth technique were exposed to 2 1C for
ca. 4-12 h after collection (see Chapter V).
- 237 -


170 -
Table C.2. Artificial data of an adult activity and the technique for
determination of the temporal frequency of that activity
during scotophase calculation of sample means,
normalized means, and percent normalized means with
weighted observations. Different years, months, and nights
have been combined.
Hour After
Sunset
Date3 Weighted*3
(D-M-Y) Observation
c
Sample
Mean
Normalized^
Mean
Percent
Mean
1
27-A-80
.03
.02
.0244
2.44
07-S-80
.01
20-A-81
.02
2
27-A-80
.10
.15
.1829
18.29
20-A-81
.10
14-S-82
.20
21-S-82
3
21-A-81
.25
.25
.3049
30.49
29-A-81
.30
24-S-81
.25
25-S-81
.20
4
17-S-81
.14
.16
.1951
19.51
10-S-82
.18
5
23-A-81
.11
.14
.1707
17.07
17-S-81
.17
6
23-A-81
.05
.06
.0732
7.32
13-S-81
.07
04-S-82
.06
7
13-S-81
.01
.02
.0244
2.44
04-S-82
.01
25-S-82
.04
8
13-S-81
.00
.01
.0122
1.22
25-S-81
.02
13-S-81
.01
9
13-S-81
.00
.00
.0000
0.00
24-A-82
.00
28-A-82
.00
10
21-A-81
.02
.01
.0122
1.22
25-A-81
.00


158 -
Table A.3. Soybean phenological stages in an ca. 1 ha field in 1982
at the Green Acres Research Farm, Alachua County, FL;
phenological stages were not determined in 1980. Sample
size varied from 30 to 70 plants, dependent upon sample
date. Plants were staged according to the methods of
Fehr and Caviness (1977).
Calender
Date
Julian
Date
Vegetative
Stage
Reproduct
Stage
June 21
172
VI
25
176
VI
-
28
179
V2
-
July 2
183
V3
5
186
V4
-
9
190
V5
-
12
193
V5
-
16
197
V6
-
19
200
V7
-
23
204
V8
-
26
207
V10
-
30
211
Vll
Rl, R2
Aug. 2
214
V12
Rl, R2
6
218
V13
R3
9
221
V13
R3
13
225
V13
R3
16
228
V14
R4
20
232
V14
R5
23
235
V14
R5
27
239
V14
R5
30
242
V14
R5
Sept. 3
246
V14
R5
6
249
V14
R5
10
253
V14
R5
13
256
V14
R5
17
260
V14
R5


PERCENT- NORMALIZED SAMPLE MEAN
HOUR AFTER SUNSET
Figure 3.2. The percent-normalized sample mean ( SE) of each post-sunset hour for activities of adult
velvetbean caterpillars: (A) mating, (B) oviposition, (C) feeding, males in aggregations,
(D) feeding, males not in aggregations, (E) feeding, all males, (F) feeding, females, (G)
feeding, unsexed adults, (H) feeding, males (all), females, and unsexed adults, and (I)
feeding, males (not in aggregations), females, and unsexed adults. Observations were made
from 1980-82 at the Green Acres Research Farm, Alachua County, FL, in a 1 ha soybean field.
i
U)
I


- 96 -
Table 4.3. The mean number (SE) of spermatophores per female per
reproductive category of adult velvetbean caterpillar.
Females were caught in a blacklight trap during 1981 at
the Green Acres Research Farm, Alachua County, FL.
£
Reproductive
Category
Total Number
of Females
Mean*3
Spermatophores/Female
(SE)
1
162
0
2
543
1.19 .02 A
3
376
1.40 .03 B
4
207
2.00 .05 C
1 = unmated, no spermatophore.
2 = mated, fat body content full to 1/3 depleted.
3 = mated, fat body content between 1/3 and 2/3 depleted.
4 = mated, fat body content 2/3 or more depleted.
^Means followed by different letters are significantly different
according to the Kruskal-Wallis Test (a = .05).


Table F.l. Mean number of freshly-laid velvetbean caterpillar
eggs per soybean plant (1981) found in a 1 ha
soybean field at the Green Acres Research Farm,
Alachua County, FL.
Calendar
Date
Julian
Date
Sample
Size
c
, Sample
! Unit
: Size
Mean No.
of Eggs/Plant
( SD)
June 23
173
30
1
.000 .000
25
176
30
1
.000 .000
29
180
30
1
.000 .000
July 6
187
30
1
.000 .000
9
190
30
1
.000 .000
12
194
30
1
.000 .000
16
197
30
1
.000 .000
20
201
30
1
.000 .000
23
204
30
1
.033 .183
27
208
70
1
.029 .168
30
211
70
1
.014 .120
Aug. 3
215
70
1
.029 .168
6
218
70
1
.014 .120
10
222
70
1
.086 .282
13
225
70
1
.086 .329
17
229
70
1
.203 .558
20
232
70
1
.200 .651
24
236
70
1
.101 .349
27
239
70
1
.214 .478
31
243
70
1
.203 .472
Sept. 3
246
70
1
.243 .494
7
250
70
1
.271 .658
14
257
70
1
.435 .630
aMean number
of soybean plants
per 0.91 m-row was
28.267.
^Sample size
was the
number of
plants sampled.
Q
Sample unit
size was
based on
an individual soyb
ean plant;
i.e., the sample unit size was
one soybean plant

273 -


FIELD VPD (mmHg) AMBIENT VPD (mmHg)
100 -
JULIAN DATE (1981)
Figure 4.7. Vapor pressure deficit (VPD) in a 1 ha soybean field in
1981 at the Green Acres Research Farm, Alachua County, FL:
(A) ambient VPD, and (B) field VPD.


- 243 -
Figure E.l. A. gemmatalis eggs: (A) freshly laid, (B) middle aged, (C)
middle aged with eye spot, (D) old or pre-eclosion, (E)
eclosed, (F) parasitized, (G) parasitized, and (H)
parasitoid emerged.


- 40 -
occurred at the study site and looked similar to VBC. Differences
between adults of these two species are discussed in Appendix B.
Temperature and humidity were monitored continuously with a
hygrothermograph (Weather Measure Corporation Model No. H311). Also,
£
temperature was monitored hourly with an Esterline Angus PD2064
Microprocessor. Rainfall was recorded continuously by a Universal
Recording Rain Gage (12" chart with dual springs, Belfort Instrument
Co.). Sunset and sunrise times were obtained from Oliver* (personal
communication). Phase and temporal occurrence of the moon were obtained
from the Astronomical Almanac (Smith and Smith 1981, and Vohden and
Smith 1982) and were noted with visual observation in the field. In
1981 and 1982, wind speed was recorded at 15 min intervals with a gill,
3-cup, anemometer (Model 12102, R. M. Young Co.). In 1981, wind
direction was recorded at 15 min intervals with a gill microvane (Model
12302, R. M. Young Co.).
Quantitative Technique
The temporal occurrence and frequency of several adult activities
(oviposition, mating, and feeding) during scotophase were examined
quantitatively. Scotophase was partitioned into hourly increments after
sunset, with the hours numbered consecutively from 1 (sunset) to 12
(sunrise). For an activity on a particular night, the amount of
observation time and the number of observations were segregated
according to their hour of occurrence. Observations were weighted with
respect to observation time to correct for a time bias (i.e., the number
of observations were divided by the amount of observation time). No
*J. P. Oliver, Associate Professor of Astronomy, Department of
Astronomy, University of Florida, Gainesville, FL 32611.


52 -
(1973) obtained similar results and found that 66%* of all mating
occurred over the same time period. Both of our results contrast
sharply with those of Leppla (1976), where 81%** of all mating for
colony adults occurred in hours 6-10 of scotophase.
The difference in Leppla's (1976) results from the results in this
study and from Greene et al. (1973) may be related to (1) colony
artifact, (2) temperature and predation, (3) moisture, or (4)
reproductive isolation. Colony adults may mate at a different time from
feral adults due to colonization. As noted above, colony adults do
behave differently than feral adults with regard to the temporal
occurrence of flight. With regard to temperature and predation, colony
adults are maintained at a constant temperature and are not exposed to
predation. Wild adults are exposed to variable and cyclic temperatures
(See NOAA 1982) and should be vulnerable to predation when mating at
certain times, as moths are highly visible and very docile. If mating
is temperature-dependent, more time will be required to complete mating
as temperature decreases during the night. Wild moths that mate in
early scotophase will complete mating before sunrise. Wild moths that
mate in late scotophase probably will not complete mating before sunrise
and will be exposed visually to predators. In a colony with constant
temperature and a lack of predation, females may "assess" the
temperature/predator risk and mate during late scotophase. Mating by
colony adults in late scotophase may favor the completion of a more
beneficial activity during early scotophase (e.g., oviposition). Also,
*Percentage value determined with calculations of data in Table 1 of
Greene et al. (1973, p. 1114).
**Percentage value determined with calculations of data in Fig. 3 of
Leppla (1976, p. 47).


25
ephemeral (see Herzog and Todd 1980), so adults must be able to fly
between hosts. Mated females exhibit early reproduction, laying 50% of
their eggs within four to nine days after emergence, and with
oviposition steadily declining thereafter (Moscardi et al. 1981c).
Total mean oviposition, for females reared as larvae on soybean, can be
as high as ca. 963 eggs/female, with an extremely high net reproductive
rate of ca. 365 (Moscardi et al. 1981b). In conjunction with this high
reproductive rate, the mean developmental time from egg hatch to adult
eclosin is ca. 22 days (Moscardi et al. 1981a). Finally, immature VBC
stages exhibit high survival, except for larval mortality during late
soybean growth from the pathogen, N. rileyi (Kish and Allen 1978, Elvin
1983, O'Neil 1984).
Velvetbean Caterpillar/Soybean Interactions
The VBC is believed to overwinter in southern Florida, the West
Indies, Central America, and much of South America. This pest is
hypothesized to migrate each year from overwintering areas into the
southern United States (Watson 1916a, Herzog and Todd 1980, Buschman et
al. 1981a). The temporal occurrence of immigration is unknown, as no
direct evidence exists (Buschman et al. 1981a), but moths invade soybean
fields in northern Florida from May to July (Greene 1976). Following
colonization, larvae reach peak densities in August or September, or
occasionally in early October (see Greene 1976, Linker 1980). As
soybean senesces, usually in mid to late October, larval populations
decline rapidly and VBC adults move to different hosts, both cultivated
and wild (Ellisor 1942, Greene 1976, and Buschman et al. 1981a). Larvae
and pupae apparently are incapable of overwintering in soybean fields,
so infestation of soybean the next year begins with adult immigration
(Watson 1916a, Buschman et al. 1981a).


246 -
Plathypena scabra (Fabricius)
Common Name:
Green Cloverworm.
Family:
Noctuidae.
Egg Development,
Color-Changes and Types:
Freshly Laid
. Light green, off white [Fig. E.2(A)].
Middle Aged
. Same as freshly laid but with speckles
Speckles are small, irregularly shaped
and reddish brown [Fig. E.2(B)].
Old (Pre-Eclosion)
. Light brown with a visible larval
head-capsule, eyes and mandibles [Fig.
E.2(C)].
Parasitized
. Black [Fig. E.2(D and E)].
Parasitoid Emerged
. Black with hole in side [Fig. E.2(F)].
Egg Shape: Top View
. Circular.
Side View
. Flattened dome or half circle. Egg in
Fig. E.2(E) was removed from substrate
and positioned for photograph. The
bottom of this egg looks circular but
was flat when attached to the
substrate.
Ridge Number:
x SD = 16.5 1.4, range 14-19, n =
38.
Ridge Morphology:
Protrude well above egg surface (i.e.,
fin like). Easy to count.
Micropylar Area:
Flat, composed of concentric circles.


181
Table C.5 (continued)
Date3
(D-M-Y)
Hour After
Sunset
Number of
Observations
of Oviposition
c
Observational
Time (min)
Weighted^
Observations
04-S-81
10
0
4
0.000000
13-S-81
10
0
60
0.000000
24-A-82
10
2
60
0.033333
28-A-82
10
3
53
0.056604
31-A-82
10
2
60
0.033333
04-S-82
10
0
51
0.000000
07-S-82
10
0
59
0.000000
ll-S-82
10
0
59
0.000000
14-S-82
10
0
60
0.000000
18-S-82
10
0
60
0.000000
21-S-82
10
0
58
0.000000
25-S-82
10
0
53
0.000000
21-A-81
11
0
56
0.000000
25-A-81
11
0
60
0.000000
28-A-81
11
0
60
0.000000
Ol-S-81
11
0
60
0.000000
04-S-81
11
0
60
0.000000
08-S-81
11
0
60
0.000000
13-S-81
11
0
6
0.000000
15-S-81
11
0
51
0.000000
ll-A-82
11
0
28
0.000000
31-A-82
11
0
36
0.000000
14-S-82
11
0
8
0.000000
18-S-82
11
0
23
0.000000
21-S-82
11
0
17
0.000000
25-S-82
11
0
32
0.000000
25-A-81
12
0
2
0.000000
28-A-81
12
0
7
0.000000


Table E.l (continued)
Eggs were found on soybean. Eclosed larvae were reared on soybean to the adult stage.
6
M. latipes larvae could not be reared on soybean but were reared on sandbur, Cenchrus sp.
^Eggs of H. zea and H. virescens are not distinguishable.
g
S. melinus is a stem borer.


287
Ellisor, L. 0. 1942. Notes on the biology and control of the
velvetbean caterpillar, Anticarsia gemmatalis Hbn. La. Agr. Exp.
Sta. Bull. 350: 17-23.
Ellisor, L. 0. and L. T. Graham. 1937. A recent pest of alfalfa. J.
Econ. Entomol. 30(2): 278-280.
Elvin, M. K. 1983. Quantitative estimation of rates of arthropod
predation on velvetbean caterpillar, Anticarsia gemmatalis Hubner,
eggs and larvae in soybeans. Ph.D. Dissertation. University of
Florida, Gainesville, FL.
Erickson, E. H. 1975. Effect of honey bees on yields of three
soybean cultivars. Crop Sci. 15: 84-86.
Erickson, E. H. and M. B. Garment. 1979. Soya-bean flowers:
Nectary ultrastructure, nectar guides, and orientation on the
flower by foraging honeybees. J. Apicultural Res. 18(1): 3-11.
FA0 (Food and Agriculture Organization of the United Nations). 1984.
1983 FAO production yearbook. FA0 Statistics Series No. 55, Rome,
Italy.
Feeny, P. 1975. Plant apparancy and chemical defense. Ln J. W.
Wallace and R. L. Mansell, eds. Biochemical interaction between
plants and insects. Plenum Press, New York, NY. Vol. 10.
Fehr, W. R. and C. E. Caviness. 1977. Stages of soybean
development. Iowa State Univ. Coop. Ext. Ser. Special Report 80:
1-12.
Fehr, W. R., C. E. Caviness, D. T. Burmood, and J. S. Pennington.
1971. Stage of development descriptions for soybeans, Glycine max
(L.) Merrill. Crop Science 11: 929-931.
Ferreira, B. S. C. and A. R. Panizzi. 1978. Distribuicao de ovos e
lagartas de Anticarsia gemmatalis Hubner em plantas de soja. Anais
Da S.E.B. 7(1): 47-53.
Foelix, R. F. 1982. Biology of spiders. Harvard University Press,
Cambridge, MA.
Forbes, W. T. M. 1954. Lepidoptera of New York and neighboring
states. Noctuidae. Part III. Cornell Univ. Agr. Exp. Sta.
Memoir. 329: 1-433.
Ford, B. J., J. Reid, J. R. Strayer, and G. L. Godfrey. 1975. The
literature of arthropods associated with soybeans. IV. A
bibliography of the velvetbean caterpillar Anticarsia gemmatalis
Hubner (Lepidoptera: Noctuidae). Illinois Nat. Hist. Surv.
Biological Notes 92: 1-15.


- 2 -
rainfall and solar radiation; biological inputs, such as natural enemies
of the pests; and production system inputs, such as irrigation,
cultivation, and application of pesticides" (Stimac and O'Neil 1985, pp.
323-324). These factors must be quantified and mathematically described
in submodels of the crop, pests, and production tactics.
One of the objectives of a multi-university investigation* was to
construct a soybean crop model that could be used to evaluate soybean
production strategies under various combinations of stresses (e.g.,
water or pests). To accomplish this objective, the Soybean Integrated
Crop Management (SICM) model was constructed. This model is composed of
an aggregate of submodels coupled to a physiologically-based plant-
growth model of soybean, and is designed to allow the user to study
various management strategies at the field level for different weather,
cultural, soil, pathogen, weed, and insect scenarios (Wilkerson et al.
1982, 1983).
One of the SICM submodels represents the population dynamics of
velvetbean caterpillar (VBC), Anticarsia gemmatalis Hubner (Lepidoptera:
Noctuidae), a major defoliating pest of soybean (Herzog and Todd 1980,
Wilkerson et al. in press). In the current version of the VBC submodel,
immigration of VBC adults into soybean has been difficult to assess
because no data of adult or egg density are available (see Wilkerson et
al. 1982). Data on adult density are essential for model
initialization, as VBC life stages do not overwinter in soybean and
infestation depends on the annual immigration of adults into soybean
investigation entitled The Development of Comprehensive, Unified,
Economically, and Environmentally Sound Systems of Integrated Pest
Managementfunded by the Environmental Protection Agency and the
United States Department of Agriculture.


226 -
Table D.6 (continued)
Wind Direction
Wind Direction = values that vary from 1 to 360,
where 90 = due east,
180 = due south,
270 = due west,
360 = due north.
Rainfall
Rainfall = R*T,
where R = proportional amount of rainfall, based on
centimeters per rainfall per night,
T = proportional length of rainfall duration, based
on hours.
Barometric Pressure (MB)
Barometric Pressure = mean barometric pressure, based on data
recorded at 1 h intervals during scotophase.


APPENDIX E
PICTORIAL KEY OF SOME LEPIDOPTERA EGGS
FOUND ON SOYBEAN


- 44 -
one or more moths were observed in this activity on four different days.
Flight activity occurred within ca. 15 min of sunset and flight distance
varied from ca. 1 m to greater than 100 m; after 100 m adults were too
difficult to observe. Flight speed and pattern usually were fast and
darting, respectively.
During scotophase, flight activity was highly evident and
temporally variable. During the first ca. 15 min after sunset, flight
activity usually was negligible with ca. 0 to 20 flights. Between ca.
15 and 30 min after sunset, flight activity appeared to double but, on
one night in September of 1980 (no record of date), several hundred
adults were observed flying at this time. From ca. .5 to 2.5 h after
sunset, flight activity peaked and then slowly decreased from ca. 2.5 to
4.5 h after sunset. Between 4.5 h post-sunset and sunrise, flight
activity was minimal and decreased steadily to zero flights at sunrise.
Flight was utilized for oviposition, mating, feeding and,
presumably, general dispersal. Flight distance varied from ca. .01 m to
greater than 100 m, but after 100 m flying adults were not observable.
Flight speed and pattern varied from slow to fast and flutter-like to
darting, respectively.
The most striking flight activity consisted of ca. 3 to 10 adults
of unknown sex that appeared to fly in formation. Five of these
3
formations were observed. Each occupied ca. 1 m in volume, occurred at
or below the top of the soybean canopy, moved in one direction across or
between rows, and varied in speed from moderately fast to fast. Flight
paths of individual moths were highly convoluted. Formations looked
like a writhing group of moths, lasted from ca. 7 to 30 sec and covered
from ca. .03 to 10 m. The nature of these formations is obscure but may
be involved with mating.


149 -
methodology (an adult trap-cage) and the acquisition of adult density
data. Model construction and validation required these adult density
data. Knowledge of the temporal occurrence of oviposition allowed for
the development of a unique egg sampling methodology, the determination
of egg age and the acquisition of egg density data. Egg density was
determined for eggs that were less than 24 h old because model
construction and validation required data on the number of eggs
oviposited in the field on a particular night.
Estimates of adult density were obtained with a blacklight trap
(relative density) at nightly intervals and an adult trap-cage (absolute
density) at weekly intervals. These estimates represented the first
quantitative assessment of adult dynamics within a soybean field. Adult
appearance (or density) in the field, as measured with a blacklight trap
(BLT), coincided with the appearance of eggs and demonstrated that adult
density can be monitored with a BLT and that a BLT is sensitive to adult
capture at low densities. Placement of the BLT in the field was
necessary to achieve this sensitivity. Dissection of adult females
caught in the BLT in 1981 revealed that most females during the season
were mated and potentially highly reproductive. Early in the field
season, mated females that flew into the field contained large amounts
of fat body, indicating that these females probably completed their
larval development on nearby hosts. In the model, all females were
mated and had reproductive rates that did not exceed literature-reported
values.
Select physical variables were explored with multiple linear
regression for their effect on blacklight trap catch. No consistently
adequate correlations among these variables and BLT catch were
uncovered, suggesting that there are no simple linear relationships


- 141
maturity, females "preferred" to lay large numbers of eggs on soybean,
with the one exception already mentioned. During late pod maturity,
soybean began to senescence and adult and egg densities declined.
Presumably, females found soybean less attractive for oviposition at
this time; consequently, ovipositional rate was set to 60 eggs per
female per night. At full pod maturity (R8) when most foliage had
senesced, eggs were not present in the field, so the ovipositional rate
was set equal to zero. Females apparently will not oviposit on
senescent soybean foliage, which is to their selective advantage as
eclosed larvae would die for lack of suitable host plant material.
The reason for the necessary decline in ovipositional rate from 220
to 80 eggs per female per night during SOY 15 (or R5) is unknown but at
least two explanations are plausible. Perhaps the adult-density
conversion function acts inappropriately at SOY 15 (or R5). This seems
unlikely as the function works well in simulations with data from 1981
(see below). Perhaps females altered their ovipositional rate in
response to an environmental variable. A high daily vapor pressure
deficit (VPD) in the field from dates 240-248 may have been the
environmental factor that affected ovipositional rate in the field and
led to the calculated value of 80 eggs per female per night [see Fig.
4.7(B)], One might anticipate that future model versions use the rate
of 210 or 220 eggs per female per night from R1 to R6, or use a function
that varies ovipositional rate with VPD.
Why or if ovipositional rate in the field varies throughout the
season in response to soybean phenological stage (as depicted in the
model) is unknown. If it does occur, it may be induced by changes in
leaf area, in VPD, in biochemical changes in the soybean, or by changes
in VBC demographics. A great diversity of stimuli are known to


Table C.8 (continued)
Date3 MaleC Maled Male* MFAh MFA1
(D-M-Y) Hour Agg OAgg All Female Adult* Agg OAgg
03-S-82 2 0
24-S-82 2 3
05-A-80 3 0
01-A-8I 3 0
15-A-81 3 0
22-A-81 3 0
26-A-8I 3 0
29-A-81 3 0
02-S-8I 3 0
09-S-81 3 0
12-S-81 3 0
17-S-8I 3 29
19-S-81 3 5
24-S-81 3 9
26-A-82 3 0
03-S-82 3 0
10-S-82 3 0
24-S-82 3 0
05-A-80 4 0
0 0 0
2 5 5
0 0 0
0 0 0
0 0 7
1 1 0
0 0 2
4 4 0
0 0 0
0 0 0
0 0 0
0 29 0
0 5 0
0 9 0
1 1 0
0 0 1
2 2 1
7 7 6
0 0 0
0 0 0
0 10 7
3 3 3
0 0 0
1 a s
o i i
0 2 2
0 4 4
0 0 0
0 0 0
0 0 0
0 29 0
0 5 0
0 9 0
0 1 1
0 1 1
0 3 3
3 16 16
2 2 2
Time1
Uelghtk
Weight1
2
WeightBI
3
Weight0
4
Weight0
5
Weight*1
6
We ight**
7
60
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
45
0.066667
0.044444
0.111111
0.111111
0.000000
0.222222
0.155556
60
0.000000
0.000000
0.000000
0.000000
0.050000
0.050000
0.050000
8
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
35
0.000000
0.000000
0.000000
0.200000
0.028571
0.228571
0.228571
32
0.000000
0.031250
0.031250
0.000000
0.000000
0.031250
0.031250
60
0.000000
0.000000
0.000000
0.033333
0.000000
0.033333
0.033333
40
0.000000
0.100000
0.100000
0.000000
0.000000
0.100000
0.100000
15
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
42
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
49
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
60
0.483333
0.000000
0.483333
0.000000
0.000000
0.483333
0.000000
18
0.277778
0.000000
0.277778
0.000000
0.000000
0.277778
0.000000
37
0.243243
0.000000
0.243243
0.000000
0.000000
0.243243
0.000000
18
0.000000
0.055556
0.055556
0.000000
0.000000
0.055556
0.055556
40
0.000000
0.000000
0.000000
0.025000
0.000000
0.025000
0.025000
38
0.000000
0.052632
0.052632
0.026316
0.000000
0.078947
0.078947
50
0.000000
0.140000
0.140000
0.120000
0.060000
0.320000
0.320000
11
0.000000
0.000000
0.000000
0.000000
0.181818
0.181818
0.181818
187


Table E.l. Techniques used to collect eggs of some Lepidoptera species found on soybean from 1980-82.
All eggs were laid on soybean. An "X" indicates that a particular technique was used for a
species.
Wild Eggs
Species Name
0
Colony
Eggs
Oviposition^
in Lab
Found in FieldC
(Oviposition
Observed)
Found in Field
(Oviposition
Not Observed)
Anticarsia gemmatalis Hubner
X
X
X
X
Plathypena scabra (Fabricius)
X
X
0
Mocis latipes (Guenee)
X
Pseudoplusia includens (Walker)
X
X
Heliothis zea (Boddie)^
X
X
X
Heliothis virescens (Fabricius)^
X
X
Urbanus proteus (Linnaeus)
X
X
Strymon melinus (Hubner)
X
Unknown
X
Colony adults were obtained from Dr. N. C. Leppla, Research Scientist, USDA Insect Attractants,
Behavior, and Basic Biology Research Laboratory, Gainesville, FL 32604.
^Wild adults were collected from soybean and allowed to oviposit on soybean in the lab.
c
Wild adults were observed to oviposit in the field.
238


248 -
Figure E.2. P. scabra eggs: (1) freshly laid, (B) middle aged, (C) old
or pre-eclosion, (D) parasitized, (E) parasitized, and (F)
parasitoid emerged.


171
Table C.2 (continued)
Hour After
Date3
Weighted^
c
Sample
Normalized^
e
Percent
Sunset
(D-M-Y)
Observation
Mean
Mean
Mean
11
28-A-81
.00
.00
.0000
0.00
01-S-81
.00
04-S-81
.00
08-S-81
.00
13-S-81
.00
12
25-A-81
.00
.00
.0000
0.00
28-A-81
.00
Total
.82
1.0000
100.00
aD-M-Y = Day, Month, Year; A = August, S = September; 80 = 1980, 81 =
1981, 82 = 1982.
^For calculation of individual weighted observations see Table C.l.
c
Sample mean of weighted observations for each hour; e.g., for first
hour after sunset, sample mean = .02 = (.03 + .01 + .02)/3.
^Normalized Mean = Sample Mean/.82.
6
Percent Mean = Normalized Mean x 100.


ACKNOWLEDGEMENTS
The inadequacy of words will inhibit me from being able to express
completely my feelings of gratitude for all of the help that I received
during my Ph.D. program, particularly with regards to my major professor
and friend, Carl Barfield. He constantly provided me with funds and
equipment for my research and always had time to encourage my endeavors
and listen to my ideas. I learned much about myself from working with
Carl and I will always be indebted to him for the opportunities he
provided me and for the scientific development I achieved under his
aegis. I admire Carl for what he has achieved as a scientist and as a
father and I will miss his sense of humor. I cannot write enough about
him. Working with Jerry Stimac, a member of my committee, has been a
very rewarding experience. His ecological insights and systems
perspectives have deeply affected my development as a scientist. Jerry
is a free thinker and an individual that loves to explore his
environment. He also has an insatiable and wonderful penchant for a
good laugh. Frank Slansky, another member of my committee, exhibits
scientific standards that I would one day like to achieve. Frank is a
remarkable scientist and I am indebted to him for his ecological
insights into my experiments. He has a fantastic sense of humor and he
never seems to miss a beat with it. He also has a wonderful family.
Interacting with Ken Boote, the last member of my committee, has been
very educational. His inquiries about my course work and research
v


Table 3.9 (continued)
Date3
(D-M-Y)
Time^
Q
Location
Spider Scientific Name1*
Spider
Common
Name
Spider
Family
Spider6
Stage
and
Sex
VBCf
Adult
Sex
16-A-8I
0000-0700
E,
Grass
Mlsumenops celer (Hentz)
Crab
Thomisldae
A, +
M
09-0-82
0530
E,
Hairy Indigo
Mlsumenops celer (Hentz)
Crab
Thomisldae
A, +
M
01-S-81
0545-0607
E,
Grass
Mlsumenops celer (Hentz)
Crab
Thomisldae
A, +
F
15-S-81
0545-0714
E,
Bahlagrass
Mlsumenops formoclpes (Walckenaer)
Crab
Thomisldae
A, F
M
I7-S-8I
2100
I.
Soybean
Eriophora ravllla (C. L. Koch)
Orbweaver
Araneldae
A. F
M
24-S-82
2332
E.
Soybean
Neoscona arabesca (Walckenaer)
Orbweaver
Araneldae
A, F
M
05-0-82
0550
E,
Soybean
Neoscona arabesca (Ualckenaer)
Orbweaver
Araneldae
A, +
M
I5-S-83
0200
E.
Bahlagrass
Acanthepelra sp.
Orbweaver
Araneldae
I. +
F
aD-M-Y -
Date, Month,
, Year; A August,
S = September, 0 October; 81 1981
, 82 1982,
83 1983.
If the exact time of a predation record is not given, the record occurred during the hyperated times.
c
E = Edge of field; record was observed within I m of the field edge. I Inside field; record was observed in the
field and at least 1 m from the field edge. Grass unidentified grass. Bahlagrass Paspalum notatum Flugge.
Hairy Indigo Indlgofera hirsuta L. Soybean Glycine max (L.) Merr. Beggarweed Desmodlum tortuosum (Sw.)
DC. Slcklepod Cassia obtualfolla L. Florida Pusley Rlchardla scabra L. Sandbur Cenchrus sp.
^Except for P. vlrldans, all spiders were identified by Dr. G. B. Edwards, Taxonomic Acarologlst and Curator, Florida
State Collection of Arthropods, Gainesville, FL. P. vlrldans1 were identified by the author, but four of these
specimens were reconfirmed by Dr. Edwards.
6
I = immature, A adult, F female, = undetermined stage, + undetermined sex.
* + = undetermined sex, M male, F female


Ill
densities. Placement of the trap in the field was necessary to achieve
this sensitivity. A number of physical variables were explored for
their effect on BLT catch. No consistently adequate correlations among
these variables and BLT catch were uncovered with regression techniques,
suggesting that other variables might affect adult density fluctuations
or that no simple linear relationships exist between these variables.
Future experimental work should be directed toward determining the
affect of various environmental variables on adult flight (e.g., wind
speed). Quantitative descriptions of these affects in the form of
mechanistic equations could be used to predict the capture of adults in
blacklight traps. Dissections of adult females revealed that most
females were found to be mated and potentially highly reproductive.
Early in the field season, mated females flew into the field and
contained large amounts of fat body, indicating that these females
probably completed their larval development on nearby hosts.
Absolute estimates of adult absolute density were obtained with a
unique sampling device, an adult trap-cage. Design and utilization of
this trap resulted from adult behavioral observations (see Chapter III).
Adult residency in the field during the day, as measured with this trap,
appeared to be delayed until an appropriate humidity level (5 mm Hg) had
been reached in the field during the day. Adult departure from the
field, as soybean senesced, apparently was not affected by the same
humidity level. To assess the true impact of humidity on VBC dynamics
will require extensive experimentation in the field on a year-round
basis in both soybean and other hosts, as well as the completion of
detailed laboratory experiments.
Estimates of the relative and absolute densities of adults were
calibrated with a regression equation. This equation could be used to


LITERATURE CITED
Altieri, M. A. 1983. Agroecology, the scientific basis of alternative
agriculture. Division of Biological Control, University of
California, Berkeley, CA. 173 pp.
Anderson, D. B. 1936. Relative humidity or vapor pressure deficit.
Ecology 17(2): 277-282.
Anonymous. 1928. The velvetbean caterpillar, a peanut pest in the
Everglades. Fla. Entomol. 12: 39-40.
Anonymous. 1974. Sexual dimorphism of Anticarsia gemmatalis leg
scales (Note). Fla. Entomol. 57(3): 280.
Angelo, M. J. 1983. Resource allocation in four presumed migratory
noctuid moths. M.S. Thesis. University of Florida, Gainesville,
FL. 84 pp.
Angelo, M. J. and F. Slansky, Jr. 1984. Body building by insects:
Trade-offs in resource allocation with particular reference to
migratory species. Fla. Entomol. 67(1): 22-41.
Arms, K., P. Feeny, R. C. Lederhouse. 1974. Sodium: Stimulus for
puddling behavior by tiger swallowtail butterflies, Papilio
glaucus. Science 185: 272-274.
Barfield, C. S. and B. Gregory, Jr. 1985. The pattern of invasion
by immigrant species. In Proc. Movement and Dispersal of Biotic
Agents Conf., Baton Rouge, LA.
Barfield, C. S. and R. J. O'Neil. 1984. Is an ecological
understanding a prerequisite for pest management? Fla. Entomol.
67: 42-49.
Baust, J. G., A. H. Benton, and G. D. Aumann. 1981. The influence
of off-shore platforms on insect dispersal and migration. Bull.
Entomol. Soc. Am. 27(1): 23-25.
Bethune, Rev. C. J. S. 1869. Notes on Canadian Lepidoptera (part
III). Can. Entomol. 1(10): 85-9.
Borror, D. J., D. M. De Long, and C. A. Triplehorn. 1981. An
introduction to the study of insects. Saunders College Pub.,
Philadelphia, PA.
285 -


281
Table G.3 (continued)
If
1
< =
SOY
<
=
5
THEN
OVI
=
0
If
5
<
SOY
<
=
9
THEN
OVI
=
40
If
9
<
SOY
<
=
14
THEN
OVI
=
220
If
14
<
SOY
<
=
15
THEN
OVI
=
80
If
15
<
SOY
<
=
17
THEN
OVI
=
210
If
17
<
SOY
<
=
19
THEN
OVI
=
60
If
19
<
SOY
<
=
20
THEN
OVI
=
0
EGG = FTOTAL (1-VF) (1-MORT) OVI;
PEGG = TEGG/12469.859;
CARDS;
/INCLUDE DMODEL82.DAT
***********************************
*** DATA FILE IS DMODEL82.DAT ***
************************************
OPTIONS NOCENTER;
PROC PRINT DATA=BG1;
VAR JULIAN SOY FBLT FTOTAL VF MORT OVI TEGG LB05 EEGG UB05 PEGG
TITLE 'MODEL 1982';
PROC PLOT DATA=BG1;
PLOT LB05*JULIAN='-'
EEGG*JULIAN='E'
UB05*JULIAN='-'
PEGG*JULIAN='P'/OVERLAY;
TITLE 'MODEL 1982';
*** THIS IS FILE PMODEL82 ***;
/*


106 -
£
Table 4.5. Regression equations of physical variables and total
numbers of males, females, and adults of the velvetbean
caterpillar. Moths were caught in a blacklight trap at the
Green Acres Research Farm, Alachua County, FL. All
parametric coefficients significant at a = .05.
1981
Female = 39.18 3.15 (Temp) + 6.46 (VPD) 24.03 (Moon)
(r2 = .45)
Male = 75.91 4.73 (Temp)
(r2 = .18)
Adult = 110.96 6.73 (Temp)
(r2 = .23)
1982
Female = 37.82 11.04 (VPD)
(r2 = .05)
Male = 9.63 + 2.26 (Temp)
(r2 = .06)
Adult = 37.56 + 3.95 (Temp) 21.05 (VPD)
(r2 = .10)
Temp = temperature (C).
VPD = vapor pressure deficit (mm Hg).
Moon = moonlight illuminence.


102 -
within the moths; i.e., adults may have been more tolerant of higher VPD
at this time of the year. Behavioral observations* tend to support this
idea, as adults have been observed outside of soybean in areas of
apparent dryness at this time of the year. The occurrence of VBC in
these dry areas may be in response to the dry season that typically
begins at this time in tropical areas. Adults appear to be well adapted
for residing in dry leaf litter, as adults apparently are leaf mimics.
The strong diagonal line across the wings may mimic a leaf main-vein.
This diagonal line is maintained when the wings are held at rest. Other
markings and patterns on the wings may represent various shadings of
dried leaves and patches of lichens (see Figs. 3.1, 3.4, 3.6 and 3.7).
Sex Ratio
The sex ratio of adults caught in the BLT (per night) and the adult
trap-cage (per week) are shown in Fig. 4.9; sex ratio is expressed as
the number of males to total adults (Pianka 1978) The dashed line in
each figure represents the seasonal mean sex ratio. The sex ratio of
BLT adults was biased toward males for all three years but tended to
show a decrease in bias as the season progressed (i.e., the sex ratios
dropped below their mean values (see Fig. 4.9). The sex ratios for 80
and '82 are .54 and .51 (respectively) and are not significantly
different, while the sex ratio in 1981 was much higher at .69 and is
significantly different (see Table 4.4). Why the sex ratio for 1981 was
so high is unknown. The sex ratio of the trap-cage adults is .35, is
*0n 25 October 1981, 12 adults were observed at Osceola National Forest
(Baker County, FL) in the grass and leaf litter of Sandhill and Pine
Flatwood Communities. On 3 October 1982, 30 adults were observed at
Cumberland Island (Camden County, GA) on dead oak leaves in the dry
understory of a Maritime Community.


198
Table C.12. Sample mean and standard error of weighted
observations of feeding velvetbean caterpillar
females grouped by post-sunset hour, along with
the percent normalized sample mean and standard
error. Observations were made from 1980-82 at the
Green Acres Research Farm, Alachua County, FL, in
a 1 ha soybean field.
Sample Mean of
the Weighted
Hour After Observations
Sunset n3 ( SE)
Percent Normalized
Sample Mean
( SE)
b
1
19
.0026
+
.0014
.87
+
.47
2
19
.0242
+
.0106
7.99
+
3.47
3
16
.0253
+
.0139
8.32
+
4.59
4
13
.0248
+
.0098
8.15
+
3.22
5
10
.0480
+
.0149
15.77
+
4.92
6
5
.0329
+
.0172
10.84

5.66
7
4
.0000
+
.0000
.00
+
.00
8
3
.0974
+
.0441
32.04
+
14.50
9
10
.0274
+
.0153
9.03
+
5.04
10
24
.0157
+
.0070
5.18
+
2.32
11
22
.0055
+
.0032
1.81
+
1.07
12
6
.0000
+
.0000
.00
+
.00
n = number of weighted observations per sample mean; n is not
the number of feeding observations. See Table C.8 for a
complete listing of all observations and observational times.
I
Percent normalized sample mean = (sample mean of weighted
observations/0.303839)*100. Percent normalized standard error
= (standard error of weighted observations/0.303839)*100.


- 294 -
Smith, J. C. and F. G. Smith, eds. 1981. The astronomical almanac.
U.S. Government Printing Office, Washington, D.C.
Stimac, J. L. 1977. A model study of a plant-herbivore system.
Ph.D. Dissertation. Oregon State University, Corvallis, OR.
Stimac, J. L. 1982. History and relevance of behavioral ecology in
models of insect population dynamics. Fla. Entomol. 65(1): 9-16.
Stimac, J. L. and C. S. Barfield. 1979. Systems approach to pest
management in soybeans, pp. 249-259. In Proc. World Soybean Conf.
II, Raleigh, North Carolina. Westview Press. Boulder, CO.
Stimac, J. L. and R. J. O'Neil. 1985. Integrating influences of
natural enemies into models of crop/pest systems, pp. 323-344. In
M. A. Hoy and D. C. Herzog, eds. Biological control in
agricultural IPM systems. Academic Press, Inc., Orlando, FL.
Stinner, R. E., C. S. Barfield, J. L. Stimac, and L. Dohse. 1983.
Dispersal and movement of insect pests. Annu. Rev. Entomol. 28:
319-335.
Strayer, J. R. 1973. Economic threshold studies and sequential
sampling for management of the velvetbean caterpillar, Anticarsia
gemmatalis Hubner, on soybeans. Ph.D. Dissertation. Clemson
University, Clemson, SC.
Sutherland, D. W. S. (Chairman). 1978. Common names of insects and
related organisms (1978 Revision). Entomological Society of
America, College Park, MD.
Tarrago, M. F. S., S. Silveira Neto, S. Carvalho and D. Barbin.
1977. Influencia de fatores ecolgicos na flutuacao populacional
das largartas da soja, Anticarsia gemmatalis Hubn., e Rachiplusia
do Brasil. 6(2): 180-193.
Tietz, H. M. 1972. An index to the described life histories, early
stages and hosts of the Macrolepidoptera of the continental United
States and Canada. The Allyn Museum of Entomology, Sarasota, FL.
Vol. 1.
Turnipseed, S. G. 1977. Influence of trichome variations on
populations of small phytophagous insects in soybean. Environ.
Entomol. 6: 815-817.
Turnipseed, S., P. Backman, G. Carlson, J. E. Jacobs, J. Jones, S.
Lewis, J. D. Newson, and H. Walker. 1979. Soybeans in the
southeast, pp. 1-57. In Pest management strategies, Vol. II -
working papers. Office of Technology Assessment, Congress of the
United States, Washington, D.C.
USDA. 1954a. Cereal and forage insects. USDA Coop. Econ. Insect.
Rep. 4: 565-573.


- 50 -
in August and September and on hairy indigo in late September in a
fallow border area (see Appendix C, Table C.3). The border area was
composed predominately of hairy indigo plants that were tall (ca. 1.5 m)
and exhibited lush, thick vegetative growth. The shift from soybean to
hairy indigo may have occurred for three reasons. First, a high
moisture level is required for VBC mating (Leppla 1976). The hairy
indigo appeared to maintain a high moisture microclimate, while soybean
was senescing. Many leaves had fallen from the soybean and moisture
around the plants was decreasing (see Chapter IV). Secondly, hairy
indigo was an ovipositional site (see below). Soybean received a low
complement of VBC eggs in late September (see Chapter V). Thirdly,
female VBC may have been attracted to the height of the hairy indigo
plants. VBC tended to mate on soybean at a height of ca. .8 m or
higher. "Calling" at this height may have increased mating success
through better pheromone dispersal.
Mating was observed only during scotophase, between sunset and
sunrise, from 1980-82 (see Appendix C, Table C3). Mating may have
occurred during photophase (sunrise to sunset), but this occurrence is
doubtful, except for times close to sunset. Low levels of moisture at
the canopy top during photophase should inhibit mating during photophase
(see Leppla 1976 and Chapter IV). Also, predation of mating moths
should be higher during photophase, as moths would be visually exposed
and immobile.
Based on the percent-normalized sample means of the weighted
observations, 79.25% of all mating occurred within the first four hours
after sunset [see Fig. 3.2(A) and Appendix C, Table C.4]. Greene et al.


118 -
Mean development times (from 1982 data) for egg speckling,
browning, and hatching were significantly different (a = 0.05) between
23.9 and 26.7C (Table 5.1). All eggs were light green when oviposited,
but 15 failed to speckle (12 at 23.9C and 3 at 26.7C). All 15 of
these eggs withered several days after oviposition and proved to be
non-viable. All other eggs demonstrated the speckling pattern that
persisted until browning. Thus, two vital components of the egg
sampling plan were assessed: (1) the color morphs associated with egg
development and (2) the temperature-dependency of egg development and
color changes.
Eggs from wild females demonstrated the same color changes as those
from colony females at 26.7C (Fig. 5.1); however, wild eggs developed
(and changed color) significantly faster (a = 0.05)(Table 5.1). The
reason for this result is unknown but could be an artifact of the small
number of colony females that were examined (n = 3).
Mean development time and rate for speckling were determined (with
1984 data) at six different temperatures with eggs from colony adults
(Table 5.2). Linear regression between developmental rate and
temperature yielded the following equation:
y = -0.080430 + 0.006566(x),
where y = developmental rate of speckling, and
x = temperature (C).
The coefficient of determination (r2) was 0.90. Slope and intercept
parameters were determined with all observations and not mean values.
The developmental zero (DZ) for speckling was 12.25C (Fig. 5.2), and
the number of degree-hours required for speckling (thermal constant) was
153.27 (Table 5.2). Replacement of the developmental rate of colony


Table C.8 (continued)
Date3
(D-M-Y)
ii b
Hour
Male*
Agg
Male**
OAgg
Hale*
All
Female^
Adult**
MKAh
Agg
MFA1
OAgg
Time
28-A-81
1 1
0
0
0
0
0
0
0
60
0I-S-8I
1 1
0
0
0
0
0
0
0
60
04-S-81
1 1
0
0
0
0
1
1
1
60
08-S-8I
1 1
0
0
0
3
0
3
3
60
13-S-81
11
0
0
0
0
1
1
l
6
I5-S-8I
1 1
0
2
2
1
0
3
3
51
31-A-82
1 1
0
0
0
0
0
0
0
36
14-S-82
1 1
0
0
0
0
0
0
0
8
18-S-82
1 1
0
1
1
0
0
1
1
23
21-S-82
11
0
0
0
0
0
0
0
17
25-S-82
1 1
0
1
1
0
0
1
1
32
02-0-82
1 I
0
0
0
0
0
0
0
35
05-0-82
11
0
1
1
2
0
3
3
39
09-0-82
1 1
0
1
1
0
0
1
1
58
25-A-8I
12
0
0
0
0
0
0
0
2
28-A-8I
12
0
0
0
0
0
0
0
7
01-S-8I
12
0
0
0
0
0
0
0
U
04-S-81
12
0
0
0
0
0
0
0
19
Weight*1 Weight* Weight Weight Weight Weight*1 Weight**
1 2 3 A 5 6 7
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.039216
0.000000
0.000000
O.OA3A78
0.000000
0.031250
0.000000
0.0256A1
0.0172A1
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.039216
0.000000
0.000000
O.OA3A78
0.000000
0.031250
0.000000
0.0256A1
0.0172A1
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.050000
0.000000
0.019608
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.051282
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
o.oooooo
0.000000
0.000000
0.166667
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.050000
0. 166667
0.05882A
0.oooooo
0.000000
0.043A78
0.oooooo
0.031250
0.000000
0.076923
0.0172A1
0.000000
0.OOOOOO
0.OOOOOO
0.000000
0.000000
0.000000
0.000000
0.050000
0. 166667
0.05882A
0.000000
0.000000
0.0A3A78
0.000000
0.031250
0.000000
0.076923
0.0172A1
0.000000
0.000000
0.000000
0.000000


Table D.2 (continued)
Number of Females
Number of Males
Number of Total
Adults
Calendar
Julian
Date
Date
Total Smoothed Weighted
Total Smoothed Weighted
Total Smoothed
Weighted
July 7
188
0
0.00
0.00
0
0.00
0.00
0
0.00
0.00
8
189
0
0.00
0.00
0
0.00
0.00
0
0.00
0.00
9
190
0
0.00
0.00
0
0.00
0.00
0
0.00
0.00
10
191
0
0.00
0.00
0
0.00
0.00
0
0.00
0.00
11
192
0
0.00
0.00
0
0.00
0.00
0
0.00
0.00
12
193
0
0.00
0.00
2
0.00
0.00
2
0.00
0.00
13
194
0
0.00
0.00
0
0.00
0.00
0
0.00
0.00
14
195
0
0.00
0.00
0
0.25
-1.00
0
0.25
-1.00
15
196
0
0.00
0.00
1
0.75
0.33
1
0.75
0.33
16
197
0
0.00
0.00
1
1.00
0.00
1
1.00
0.00
17
198
0
0.00
0.00
1
0.75
0.33
1
0.75
0.33
18
199
0
0.00
0.00
0
0.25
-1.00
0
0.25
-1.00
19
200
0
0.00
0.00
0
0.00
0.00
0
0.00
0.00
20
201
0
0.00
0.00
0
0.00
0.00
0
0.00
0.00
21
202
0
0.00
0.00
0
0.00
0.00
0
0.25
-1.00
22
203
1
0.00
0.00
0
0.50
-1.00
1
1.00
0.00
23
204
0
0.00
0.00
2
1.50
0.33
2
1.75
0.14
24
205
1
0.00
0.00
2
2.00
0.00
3
2.00
0.50
207


164 -
Differences in leg scales of the two species are evident.
A. gemmatalis, tufts of long setae occur only on the tibiae of
metathoracic legs [Fig. B.l(B), letter e]. On male M. latipes,
On male
tufts of
long setae on the metathoracic legs occur on the tibiae and the tarsi
[Fig. B.2(B), letter e].


Table 2.4 (continued)
Family
Leguminosae
Scientific Name
Dolichos lablab L.
Galactia spiciformis
Glycine max (L.) Merrill
Indigofera hirsuta L.
Lespedeza sp.
Medicago sativa L.
Melilotus alba Desr. in Lam.
Pachyrhizus erosus (L.) Urban
Phaseolus calcaratus Roxb.
Phaseolus lathyroides L.
Phaseolus limensis Macf.
0
Phaseolus max
0
Phaseolus semierectus
Phaseolus speciosus H.B.K.
Common Name
Reference
Hyacinth Bean
Buschman et al. (1977)
Galactia
Torr. and Gray
Buschman et al. (1977)
Soybean
Nickels (1926)
Hairy Indigo
Buschman et al. (1977)
USDA (1954a)
Alfalfa
Ellisor and Graham (1937)
White Sweet Clover
Waddill (1981)
Yam Bean
Buschman et al. (1977)
Frijolito Rojo
Gutierrez and Pulido (1978)
Wild Bean
Buschman et al. (1977)
Lima Bean
Ford et al. (1975)
Wolcott (1936)
Tietz (1972)
Sweet Pea Vine
Buschman et al. (1977)


199
Table C.13. Sample mean and standard error of weighted
observations of feeding by unsexed velvetbean
caterpillar adults grouped by post-sunset hour,
along with the percent normalized sample mean and
standard error. Observations were made from
1980-82 at the Green Acres Research Farm, Alachua
County, FL, in a 1 ha soybean field.
Hour After
Sunset
b
n
Sample Mean of
the Weighted
Observations
( SE)
c
Percent Normalized
Sample Mean
( SE)
1
19
.0169
.0072
12.31
5.26
2
19
.0070
.0048
5.10
3.51
3
16
.0087
.0049
6.30
3.55
4
13
.0234
.0153
17.01
11.11
5
10
.0122
.0105
8.87
7.62
6
5
.0109
.0109
7.93
7.93
7
4
.0250
.0250
18.18
18.18
8
3
.0111
.0111
8.08
8.08
9
10
.0017
.0017
1.21
1.21
10
24
.0116
.0074
8.41
5.35
11
22
.0091
.0076
6.61
5.51
12
6
.0000
.0000
.00
.00
Unsexed adults flew out of sight before a positive sexual
identification could be made.
^n = number of weighted observations per sample mean; n is not
the number of feeding observations. See Table C.8 for
complete a listing of all observations and observational
times.
c
Percent normalized sample mean=(sample mean of weighted
observations/0.137529)*100. Percent normalized standard
error=(standard error of weighted observations/0.137529)*100.


247 -
Spatial Occurrence: Eggs laid singly.
Similar Eggs and Differences: A. gemmatalis and M. latipes have about
twice as many ridges.


128 -
time "t"; field estimated mortality values for eggs were used in the
calculations. No direct estimates of adult and egg densities existed
prior to the present study. Knowledge of adult influx patterns and
ovipositional capacities within soybean fields is necessary to be able
to adequately model VBC dynamics in soybean. The goal of the present
study is to describe the relationship between VBC adult and egg
densities in soybean and to construct a model that simulates changes in
VBC egg density.
Model Objective
The model objective is to mimic VBC egg density in a soybean field.
The behavioral criterion of this objective is to simulate changes in the
density of VBC eggs in .91 m-row of soybean within the 95% confidence
intervals of field estimates. Field estimates of egg density were made
twice-a-week. Inputs into the model include (1) the number of adult
females caught in a blacklight trap, (2) soybean field size, and (3)
soybean phenological stage.
Data Requirements for Model Construction and Validation
Model construction and validation are based on data collected at
the Insect Population Dynamics Laboratory (1980-84) of the University of
Florida, and at the Green Acres Research Farm (1980-82) near
Gainesville, FL. At the farm, data were collected in a 1 ha soybean
field (cv. Bragg, see Appendix A for agronomic details and soybean
phenological stages). The temporal resolution of the model is daily but
model output is compared to field data taken at twice-a-week intervals.
The spatial resolution of the model is a soybean field and is set by
specifying the number of rows and row length in the soybean field.
Daily temporal resolution was selected so that the number of
females caught on a particular night in the blacklight trap could be


Table 4.1 (continued)
Physical
Variable
Monitoring Device
or Source
Site8
Location
Frequency
of Reading
Yearb
Monitored
Moon Phase and
Temporal Occurrence
Smith and Smith (1981),
Vohden and Smith (1982)
Alachua County,
FL
Nightly
81,82
Proportional
Moonlight Intensity
(lumens/m2)
Gardiner (1968)
Alachua County,
FL
Nightly
81,82
Opaque Cloud
Coverage
NOAA (1981; 1982)
Alachua County,
FL
Nightly
81,82
Edge was within 50 m of
the field edge. Ambient was
at a height of 1.5 m.
Field was within
the field,
at least 15 m from nearest field edge, and at a height of .2m.
b81 = 1981; 82 = 1982.
c
Actual readings were recorded by the Esterline Angus PD2064 Microprocessor.
^J. P. Oliver, Associate Professor of Astronomy, Department of Astronomy, University of Florida,
Gainesville, FL 32611.


157
Table A. 2. Soybean phenological stages in an ca. 1 ha field in 1981
at the Green Acres Research Farm, Alachua County, FL;
phenological stages were not determined in 1980. Sample
size was 70 plants per sample date. Plants were staged
according to the methods of Fehr and Caviness (1977).
Calender
Date
Julian
Date
Vegetative
Stage
Reproduct
Stage
June 22
173
VC
25
176
VI
-
29
180
V2
-
July 6
187
V3
-
9
190
V4
-
13
194
V5
-
16
197
V6
-
20
201
V7
-
23
204
V7
-
27
208
V8
-
30
211
V9
Rl, R2
Aug. 3
215
V10
R2
6
218
Vll
R2
10
222
V12
R3
13
225
V13
R3
17
229
V13
R3
20
232
V13
R4
24
236
V13
R5
27
239
V13
R5
31
243
V13
R5
Sept. 3
246
V13
R5
7
250
V13
R5
14
257
V13
R5
21
264
V13
R6
29
272
V13
R7
Oct. 4
277
V13
R8
13
286
V13
R8


- 32 -
sunset. This activity was characterized by apparently indiscriminate
flight around the cage, followed by walking on the sides of the cage,
and rapid fluttering of wings" (Johnson et al. 1981, p. 529).
Mating
Watson (1915, p. 60) stated that, "mating undoubtedly takes place
at night." Watson (1916a, p. 525) furthered his observations when "a
single pair was observed mating in the cages [sic]. This occurred about
dusk. They remained in coitu only a few seconds."
The first detailed observations of mating behavior were published
by Greene et al. (1973). Observations were made during seven
consecutive scotophase periods inside a 1.83 x 1.83 x 3.66 m screen cage
placed over soybean. Male activity was observed when a female, "with
her moving wings outstretched horizontally" (Greene et al. 1973, p.
1113), pointed her abdominal tip dorsally (or ventrally as in one
observation). Males, usually two to five, were attracted from .61-1.83
m. A mating pheromone was postulated.
Greene et al. (1973) noted additionally that mating activity
consisted of five stages: pheromone release, male response, mounting by
the male, sperm transfer, and separation. Males flew in an upwind zigzag
pattern to locate a female. Females were approached from behind,
stroked vigorously with the male's antennae, and mounted dorsally for
1-10 sec (x = 5 sec). Males then rotated 180 toward the rear of the
female, so that their heads pointed in opposite directions. The legs of
both adults were on a leaf surface, and females always faced skyward.
Adults remained opposite to each other for the remainder of the
copulatory period, were docile if disturbed, and moved very little.
"The majority of the copulations began within 2 h postsunset and
considerably fewer after 10 PM. The time spent in copulation ranged


BIOGRAPHICAL SKETCH
A long long time ago, I was born in Charlotte, North Carolina (May
28, 1951). My wonderful parents, Ben and Nancy Gregory, bestowed upon
me the immortal need to move and live in different places. So far I
have lived in either 33 or 34 different places, and for someone of my
youth there is no telling how many additional places I will be able to
move to before my life is over. If everything falls into place my name
will appear in the Guinness Book of World Records. Anyway, during one
of my migratory urges in 1978, I discovered that I liked moths and
butterflies, so I dashed off to the University of Florida to become an
entomologist and be rich and famous. Since that time I've become a
renowned entomologist and scientist, and I dare write that my reputation
has reached such gigantic proportions that it is not uncommon to hear my
name spoken with the likes of Darwin, Pasteur and Edison.
These past eight years in graduate school have been extremely
rewarding, as I have learned everything you ever wanted to know about
the velvetbean caterpillar but were afraid to ask. Believe me, there
are people that are afraid to ask questions about this animal.
Fortunately, a few years ago I stumbled into Snuffy's Restaurant and Bar
where I have since spent many a night signing autographs, drinking
Heinekens with my friends and chasing all of those gorgeous ladies that
frequented the bar.
Gainesville and its memories are history, as I have moved to the
cultural mecca of Louisiana, replete with crayfish and Cajuns. However,
297 -


Table D.3 (continued)
Number of Females
Number of Males
Number of Total
Adults
Calendar
Julian
Date
Date
Total Smoothed Weighted
Total Smoothed Weighted
Total Smoothed
Weighted
Aug. 12
224
10
12.84
-0.22
18
26.65
-0.32
28
40.00
-0.30
13
225
11
12.55
-0.12
18
21.06
-0.15
29
33.86
-0.14
14
226
15
14.85
0.01
23
25.11
-0.08
38
39.79
-0.05
15
227
20
20.99
-0.05
34
39.27
-0.13
54
59.90
-0.10
16
228
31
30.26
0.02
62
55.44
0.12
93
85.28
0.09
17
229
51
38.35
0.33
70
61.50
0.14
121
99.46
0.21
18
230
37
41.25
-0.10
63
60.85
0.04
100
102.42
-0.02
19
231
48
39.50
0.22
72
51.98
0.39
120
91.97
0.30
20
232
37
33.88
0.09
22
33.57
-0.34
59
66.49
-0.11
21
233
24
27.33
-0.12
11
20.75
-0.47
35
46.34
-0.24
22
234
19
24.09
-0.21
21
18.27
0.15
40
41.29
-0.03
23
235
-
-
-
-
-
-
-
-
-
24
236
28
23.52
0.19
22
18.69
0.18
50
42.88
0.17
25
237
26
25.34
0.03
16
19.31
-0.17
42
45.56
-0.08
26
238
19
31.93
-0.40
18
22.56
-0.20
37
55.84
-0.34
27
239
75
45.11
0.66
86
33.36
1.58
161
78.48
1.05
28
240
43
60.29
-0.29
38
51.72
-0.27
81
109.05
-0.26
29
241
64
71.98
-0.11
34
70.21
-0.52
98
137.84
-0.29
216


107
£
Table 4.6. Regression equations of physical variables and weighted
numbers of males, females, and adults of the velvetbean
caterpillar. Moths were caught in a blacklight trap at the
Green Acres Research Farm, Alachua County, FL. All
parametric coefficients are significant at a = .05.
1981
Female = 16.74 0.25 (Moon) + 0.02 (Baro)
(r2 = .03)
Male = 0.58 0.003 (Windd)
(r2 = .01)
Adult, no variables met the .05 significance level.
1982
Female = 24.66 0.14 (VPD) + 2.94 (Rain) 0.02 (Baro)
(r2 = .05)
Male = 0.17 0.24 (VPD) + 0.26 (Moon) + 3.34 (Rain)
(r2 = .06)
Adult = 0.15 0.20 (VPD) + 0.27 (Moon) + 3.62 (Rain)
(r2 = .06)
Moon = moonlight illuminence.
Baro = barometric pressure (MB).
Windd = wind direction.
VPD = vapor pressure deficit (mm Hg).
Rain = rainfall (cm).


I certify that I have read this study and that in my opinion it
conforms to acceptable standards of scholarly presentation and is fully
adequate, in scope and quality, as a dissertation for the degree of
Doctor of Philosophy.
C. S. Barfield, (ttdairman
Professor of Entomology and Nematology
I certify that I have read this study and that in my opinion it
conforms to acceptable standards of scholarly presentation and is fully
adequate, in scope and quality, as a dissertation for the degree of
Doctor of Philosophy.
Associate Professor of Entomology and
Nematology
I certify that I have read this study and that in my opinion it
conforms to acceptable standards of scholarly presentation and is fully
adequate, in scope and quality, as a dissertation for the degree of
Doctor of Philosophy.
Associate Professor of Entomology and
Nematology
I certify that I have read this study and that in my opinion it
conforms to acceptable standards of scholarly presentation and is fully
adequate, in scope and quality, as a dissertation for the degree of
Doctor of Philosophy.
Professor of Agronomy
This dissertation was submitted to the Graduate Faculty of the College
of Agriculture and to the Graduate School, and was accepted as partial
fulfillment of the requirements for the egree of Doctor of Philosophy.
May, 1986
aJz t-
Dean,/Obllege of Agriculture
&
Dean, Graduate School


- 266 -
Strymon melinus (Hubner)
Common Name:
Family:
Egg Development,
Color-Changes and Types:
Egg Shape: Top View
Side View
Ridge Number:
Chorion Morphology:
Micropylar Area:
Spatial Occurrence:
Similar Eggs and Differences:
Gray Hairstreak.
Lycaenidae.
Unknown, but observed eggs were whitish
green [Fig. E.7(A)]. Eclosed eggs were
whitish. Not known if chorion usually
is eaten [Fig. E.7(B)].
Circular
Not distinct.
Not countable or observable.
Egg surface is covered with tiny
outward projections of the chorion.
Not distinct.
Eggs laid singly.
Other hairstreaks, but none were
observed.


- 291 -
Luna, J. M. 1979. A tactical economic threshold model for velvetbean
caterpillar (Anticarsia gemmatalis Hubner) in Florida soybean.
M.S. Thesis. University of Florida, Gainesville, FL.
MacArthur, R. H. and E. 0. Wilson. 1967. The theory of island
biogeography. Princeton Univ. Press, Princeton, NJ.
MacKenzie, D. R., C. S. Barfield, G. G. Kennedy, and R. D. Berger, eds.
1985. The movement and dispersal of agriculturally important
biotic agents. Claitor's Publishing Co., Baton Rouge, LA.
Mallows, C. L. 1973. Some comments on C Technometrics. 15(4):
661-675. P
Matthews, R. W. and J. R. Matthews. 1978. Insect behavior. John
Wiley and Sons, New York, NY.
McCord, E. 1974. Survey and control of some lepidopterous larvae
destructive to the pigeon pea Cajanus cajan (L.) Millspaugh. M.S.
Thesis. University of Florida, Gainesville, FL.
McFarland, D. 1976. How animal behavior became a science. New
Scientist 72(1027): 376-379.
McGregor, S. E. 1976. Insect pollination of cultivated crop plants.
United States Government Printing Office, Washington, DC. USDA
Handbook 496.
Menke, W. W. 1973. A computer simulation model: The velvetbean
caterpillar in the soybean agroecosystem. Fla. Entomol. 56(2):
93-102.
Menke, W. W. and G. L. Greene. 1976. Experimental validation of a
pest management model. Fla. Entomol. 59(2): 135-142.
Morse, W. J. 1927. Soy beans: Culture and varieties. USDA
Farmers Bull. 1520: 1-33.
Morse, W. J., J. L. Carter, and L. F. Williams. 1949. Soybeans:
Culture and varieties. USDA Farmers Bull. 1520: 1-38.
Moscardi, F. 1979. Effect of soybean crop phenology on development,
leaf consumption, and oviposition of Anticarsia gemmatalis Hubner.
Ph.D. Dissertation. University of Florida, Gainesville, FL.
Moscardi, F., C. S. Barfield, and G. E. Allen. 1981a. Consumption
and development of velvetbean caterpillar as influenced by soybean
phenology. Environ. Entomol. 10(6): 880-884.
Moscardi, F., C. S. Barfield, and G. E. Allen. 1981b. Impact of
soybean phenology on velvetbean caterpillar (Lepidoptera:
Noctuidae): Oviposition, egg hatch, and adult longevity. Can.
Ent. 113: 113-119.


- 292 -
Moscardi, F., C. S. Barfield, and G. E. Allen. 1981c. Effects of
temperature on adult velvetbean caterpillar oviposition, egg hatch,
and longevity. Ann. Entomol. Soc. Am. 74(2): 167-171.
Neal, T. M. 1974. Predaceous arthropods in the Florida soybean
agroecosystem. M.S. Thesis. University of Florida, Gainesville,
FL.
Nemec, S. J. Effects of lunar phases on light-trap collections and
populations of bollworm moths. J. Econ. Entomol. 64(4): 860-864.
Nickel, D. A. 1976. The peanut agroecosystem in central Florida:
Economic thresholds for defoliating noctuids (Lepidoptera,
Noctuidae); associated parasites; hyperparasitism of the Apanteles
complex (Hymenoptera, Braconidae). Ph.D. Dissertation. University
of Florida, Gainesville, FL.
Nickels, C. B. 1926. An important outbreak of insects infesting
soy beans in lower South Carolina. J. Econ. Entomol. 19: 614-618.
Nielsen, E. T. 1958. The method of ethology. Proc. Tenth Int.
Congress Entomol. 2: 563-565.
Nishijima, Y. 1960. Host plant preference of the soybean pod borer,
Grapholitha glicinivorella Matsumura (Lep., Eucosmidae). I.
Oviposition site. Entomol. Exp. Appl. 3: 38-47.
NOAA (National Oceanic and Atmospheric Administration). 1981.
Surface weather observations, Gainesville, FL. Environmental Data
Services, National Climatic Center, Asheville, NC.
NOAA (National Oceanic and Atmospheric Administration). 1982.
Surface weather observations, Gainesville, FL. Environmental Data
Services, National Climatic Center, Asheville, NC.
Oliveira, E. B. 1981. Effect of resistent and susceptible soybean
genotypes at different phenological stages on development, leaf
consumption, and oviposition of Anticarsia gemmatalis Hubner. M.S.
Thesis. University of Florida, Gainesville, FL.
Oliveira, E. B., D. C. Herzog, and J. L. Stimac. 1984. Efeito de dois
genopipos de soja, resistente e suscetivel, na populacaa de
Anticarsia gemmatalis Hubner e incidencia de Nomuraea rileyi
(Farlow) Samson. Anais da Sociedade Entomolgica do Brasil 13(2):
281-294.
Oloumi-Sadeghi, H., W. B. Showers, and G. L. Reed. 1975. European corn
borer: Lack of synchrony of attraction to sex pheromone and
capture in light traps. J. Econ. Entomol. 68(5): 663-667.
O'Neil, R. J. 1984. Measurement and analysis of arthropod predation
on velvetbean caterpillar, Anticarsia gemmatalis Hubner. Ph.D.
Dissertation, University of Florida, Gainesville, FL.


200 -
Table C.14. Sample mean and standard error of weighted
observations of feeding by males (all), females,
and unsexed velvetbean caterpillar adults grouped
by post-sunset hour, along with the percent
normalized sample mean and standard error.
Observations were made from 1980-82 at the Green
Acres Research Farm, Alachua County, FL, in a 1 ha
soybean field.
Sample Mean of
the Weighted
Percent Normalized*2
Hour After
Observations
Sample Mean
Sunset
D
n
( SE)
( SE)
1
19
.0505
+
.0189
4.51
+
1.69
2
19
.0805
+
.0263
7.19
+
2.35
3
16
.1204
+
.0363
10.76
+
3.25
4
13
.1141

.0277
10.19
+
2.47
5
10
.3562

.1645
31.81
+
14.70
6
5
.0741

.0509
6.62
+
4.54
7
4
.0250

.0250
2.23
+
2.23
8
3
.1963
+
.1004
17.53
+
8.97
9
10
.0433
+
.0218
3.87
+
1.94
10
24
.0366
+
.0114
3.27
+
1.02
11
22
.0227
+
.0084
2.02
+
.75
12
6
.0000
+
.0000
.00
+
.00
Unsexed adults flew out of sight before a positive sexual
identification could be made.
n = number of weighted observations per sample mean; n is not
the number of feeding observations. See Table C.8 for a
complete listing of all observations and observational times.
Percent normalized sample mean = (sample mean of weighted
observations/1.11958)*100. Percent normalized standard error
= (standard error of weighted observations/1.11958)* 100.


183 -
Table C.6. Sample mean and standard error of weighted
observations of oviposition by female velvetbean
caterpillar grouped by post-sunset hour, along with
the percent normalized sample mean and standard error.
Observations were made from 1980-82 at the Green Acres
Research Farm, Alachua County, FL, in a 1 ha soybean
field.
Hour After
Sunset
a
n
Sample Mean
of the Weighted
Observations
( SE)
Percent
Normalized
Sample Mean
( SE)
1
14
.0580
+
.0181
29.35
9.15
2
14
.0489
+
.0138
24.72
7.00
3
12
.0301
+
.0151
15.20
7.65
4
10
.0306
+
.0150
15.45
7.60
5
9
.0058
+
.0058
2.96
2.96
6
4
.0167
+
.0118
8.43
5.96
7
3
.0000
+
.0000
.00
.00
8
2
.0000
+
.0000
.00
.00
9
10
.0000
+
.0000
.00
.00
10
16
.0077
+
.0043
3.90
2.18
11
14
.0000
+
.0000
.00
.00
12
6
.0000

.0000
.00
.00
n = number of weighted observations per sample mean; n is not
the number of ovipositional observations. See Table C.5 for a
complete listing of all observation and observational times.
Percent normalized sample mean = (sample mean of the weighted
observations/0.197760)*100. Percent normalized standard error =
(standard error of the sampled mean/ 0.197760)*100.


MEAN NUMBER OF ADULTS MEAN NUMBER OF MALES MEAN NUMBER OF FEMALES
- 98 -
I0r
6 -
4 -
2 -
A.
I I
O M I I I i I
200 210 220 230 240 250 260 270 280 290
IOr
2 -
0 u
B.
L
-J I I L.
I I
J 1 I 1 I l
200 210 220 230 240 250 260 270 280 290
|6r
- C.
12
L
l I
l 1 I L.
200 210 220 230 240 250 260 270 280 290
JULIAN DATE (1982)
Figure 4.6. Mean number ( 90% confidence interval) of velvetbean
caterpillar moths captured per sample (21.16 m2) with the
adult trap-cage: (A) females, (B) males, and (C) adults
(females and males). Trap-cage was used in a 1 ha soybean
field during 1982 at the Green Acres Research Farm, Alachua
County, FL.


137 -
performance is validated against the real system (Stimac 1977, Overton
1977).
The model objective of the present study is to mimic VBC egg
nightly density in a soybean field. The behavioral criterion of this
objective is to simulate densities of VBC eggs per .91 m-row of soybean
within 95% confidence intervals of field estimates made at twice-a-week
intervals. The model inputs are (1) adult female density from a
blacklight trap, (2) field size, and (3) soybean phenological stage.
The goal of the present behavioral analysis is to obtain desired model
behavior with 1982 egg density data (i.e., mimic field estimates of egg
density) and to validate model behavior against the 1981 field estimates
of egg density. Several simulations were conducted to accomplish this
goal.
Simulation of 1982 Egg Population with a Constant Ovipositional Rate
Initial simulations with the model were made with constant nightly
ovipositional rates that did not exceed rates reported in the literature
(see Moscardi et al. 1981b, 1981c, Olivera 1981, Olivera et al. 1984).
A rate of 220 eggs per female per night yielded the most appropriate
model behavior, but this behavior was deemed inadequate as only 12 of 34
predicted values fell within the 95% confidence intervals of the
estimated field densities (see Fig. 6.2). The upper and lower values of
the confidence intervals are represented in Fig. 6.2 as hypens.
Predicted values tended to fall outside of the confidence intervals in
groups, indicating that a variable ovipositional rate might provide more
adequate behavior.
Simulation of 1982 Egg Population with a Variable Ovipositional Rate
Model behavior was explored with an ovipositional rate that varied
with soybean phenological stage. Model behavior was deemed adequate


Table D.2 (continued)
Calendar
Date
Julian
Date
Number of
Females
Number of
Males
Number of Total
Adults
Total
Smoothed
Weighted
Total
Smoothed
Weighted
Total
Smoothed
Weighted
Aug. 30
242
8
8.75
-0.09
9
13.50
-0.33
17
23.00
-0.26
31
243
3
11.50
-0.74
1
13.38
-0.93
4
27.75
-0.86
Sept. 1
244
14
14.25
-0.02
23
13.13
0.75
37
34.25
0.08
2
245
21
16.75
0.25
39
12.19
2.20
60
34.19
0.76
3
246
18
18.00
0.00
9
10.56
-0.15
27
28.56
-0.05
4
247
11
18.00
-0.39
3
9.75
-0.69
14
25.75
-0.46
5
248
18
18.00
0.00
14
9.75
0.44
32
25.75
0.24
6
249
21
18.00
0.17
13
9.75
0.33
34
25.00
0.36
7
250
6
18.00
-0.67
3
10.50
-0.71
9
24.75
-0.64
8
251
10
18.19
-0.45
16
16.00
0.00
26
30.50
-0.15
9
252
16
18.56
-0.14
32
32.25
-0.01
48
48.00
0.00
10
253
20
18.75
0.07
68
53.19
0.28
88
70.25
0.25
11
254
18
19.06
-0.06
62
74.00
-0.16
80
90.44
-0.11
12
255
37
21.94
0.69
195
95.31
1.05
232
113.31
1.05
13
256
14
26.75
-0.48
102
105.75
-0.04
116
130.25
-0.11
14
257
30
29.00
0.03
175
106.25
0.65
205
134.50
0.52
15
258
29
29.00
0.00
104
104.00
0.00
133
133.00
0.00
16
259
23
28.25
-0.19
83
95.38
-0.13
106
123.94
-0.14
210


174 -
Table C.3 (continued)
Date3
(D-M-Y)
Hour After
Sunset
Number of
Observations
of Mating
c
Observational
Time (min)
Weighted^
Observations
17-S-81
4
5
45
0.111111
19-S-81
4
3
45
0.066667
03-S-82
4
14
60
0.233333
10-S-82
4
2
60
0.033333
24-S-82
4
9
60
0.150000
16-A-81
5
0
35
0.000000
23-A-81
5
0
60
0.000000
27-A-81
5
0
33
0.000000
12-S-81
5
0
21
0.000000
17-S-81
5
0
28
0.000000
03-S-82
5
0
11
0.000000
04-S-82
5
1
19
0.052632
10-S-82
5
0
19
0.000000
24-S-82
5
1
37
0.027027
25-S-82
5
0
18
0.000000
16-A-81
6
0
55
0.000000
23-A-81
6
0
42
0.000000
13-S-81
6
2
44
0.045455
04-S-82
6
1
60
0.016667
25-S-82
6
4
60
0.066667
16-A-81
7
0
30
0.000000
13-S-81
7
1
21
0.047619
04-S-82
7
0
11
0.000000
25-S-82
7
0
3
0.000000
16-A-81
8
0
60
0.000000
13-S-81
8
0
39
0.000000
25-S-81
8
1
33
0.030303
16-A-81
9
0
60
0.000000
13-S-81
9
0
60
0.000000


Figure 3.8. Green lynx spider [Peucetia viridans (Hentz)] preying on an adult male velvetbean
caterpillar. Photograph was made at the edge of a 1 ha soybean field at the Green Acres
Research Farm, Alachua County, FL, 19 September 1983.


- 90 -
and '82, ca. three times that number were captured (2106 and 1989
adults, respectively). At this time of the field season, most of these
adults were moving into the field from outside sources. Differences in
the number of captured adults among years may have been due to the
amount of rainfall in the general area; adult dynamics are sensitive to
moisture (see Leppla 1976). In July and August of '81, 20 cm of rain
fell, while in '80 and '82 ca. 30 cm of rain fell or ca. 33% more rain
(see Table 4.2). Rainfall for all three years was below normal, but
July and August in '81 were particularly dry with less than half of the
70 year mean.
In '80, males were the predominant BLT catch during the first half
of the field season and females were predominant in the latter half. In
'81 males were the predominant catch throughout the field season and in
'82 both sexes were equally predominant [see Fig. 4.2 (A-C)]. The
reason for variation in sex predominance between years is unknown.
Adult appearance in the field was synchronized with the appearance
of eggs. In '81, eggs were found on July 24 (date 205) and consistently
thereafter (see Chapter V). Adults were captured consistently from July
22 (date 203). The first adult female was captured on this same date
[see Fig. 4.2(B) and Appendix D, Table D.2]. In '82, eggs were found
initially on July 6 (date 187) and consistently after July 17 (date
198)(See Chapter V). Adults were captured consistently from July 9
(date 190)[see Fig. 4.2(C) and Appendix D, Table D.3].
Female Dissections
All females captured in the BLT in 1981 were dissected and placed
into four reproductive categories (see Materials and Methods). A total
of 1288 females were dissected. Category 2 contained the largest number
of females (543), category 3 had the next largest (376), and categories


- 280 -
Table G.3. SAS program of 1982 model of adult and egg populations of
velvetbean caterpillar. To run the model without a variable
oviposition rate replace the present OVI function with the
phrase "OVI = 220;". Data file of the model is listed in
Table G.4.
//PMODEL82 JOB (1001,2064,5,5,0),'BMG',CLASS=A,MSGLEVEL=(2,0)
/*PASSWORD
/*R0UTE PRINT LOCAL
//EXEC SAS,REGI0N=800K
*************** ******** ******
*** PMODEL82 = PROGRAM, MODEL, 1982 ***
***********************************************************************.
***********************************************************************
***
***
***
***
***
***
***
***
***
IN THE INPUT
JULIAN =
FBLT =
LB05 =
STATEMENT:
Julian date.
Total number of females captured in BLT.
Lower bound of 95% confidence interval, egg
density per .91 m-row.
EEGG = Estimated egg density per .91 m-row.
UB05 = Upper bound of 95% confidence interval, egg
density per .91 m-row.
SOY = Soybean phenological stage.
***
***
***
***
***
***
***
***
***
***********************************************************************
***********************************************************************
***
IN THE EQUATIONS:
***
***
FTOTAL
=
Total number of females in the field.
***
***
VF
=
Virgin females, proportion of females that
***
***
are not mated.
***
***
MORT
=
Mortality (proportional) of mated females
***
***
per day.
***
***
OVI
=
Total number of eggs laid per female.
***
***
TEGG
=
Total number of eggs laid in the field.
***
***
PEGG
=
Predicted egg density per .91 m-row. The
"k*f*
***
constant, 12469.859, represents the total
***
***
number of .91 m-row sections of soybean in
***
***
the field.
***
it**********************************************************************.
DATA BG1;
INPUT JULIAN FBLT LB05 EEGG UB05 SOY;
FTOTAL = 134.11 + 23.20*FBLT;
VF = 0;
MORT = 0;


Figure 3.1. Mating pair of adult velvetbean caterpillar on a soybean leaflet. Adults
are in opposing position, with the male facing downward, or earthward.
Photograph taken at Green Acres Research Farm, University of Florida,
Alachua County, FL, 19 September 1982.


- 29 -
flight activity and oviposition? and (4) What environmental factors
affected the movement of adults in and out of soybean? In addressing
these questions, additional behavioral observations were recorded.
Literature Review
General Activity
Circadian rhythms of locomotion for colonized adults have been
determined with a vibration-sensitive actograph (Leppla 1976). Males
and pairs were diurnal predominately during the first 6 days after
emergence and nocturnal from the sixth day until death. Females became
nocturnal within 48 h of emergence. The general activity of adults in
all categories (i.e., isolated sexes and pairs) was age dependent; most
activity occurred in the first week after emergence. For paired adults,
74% of all activity was expressed during the first week.
Flight in the Laboratory
Circadian rhythms of flight frequency for colonized adults were
determined with an actograph system (Leppla et al. 1979). Flight
activity, monitored for 18 days, was exceptionally erratic. Nocturnal
and diurnal flights were common during the first six days after
emergence for isolated sexes and pairs. Following the sixth day,
flights were nocturnal predominately. No significant differences in
flight activity were noted among males, females, or pairs, but pairs
exhibited the least activity and isolated females exhibited the most
activity. Flight activity for all categories decreased with age.
A pivot-stick actograph was used to examine tethered flight of VBC
adults (Wales et al. 1985). No significant differences were detected
with regard to mean flight frequency (number of flights) or mean flight
duration (time of flight) among all seven comparisons of colony versus
wild adults and mated versus unmated adults. For mated and unmated


- 286 -
Bowden, J. and B. M. Church. 1973. The influence of moonlight on
catches of insects in light-traps in Africa. Part II. The effect
of moon phase on light-trap catches. Bull. Entomol. Res. 63:
129-142.
Buntin, G. D. 1980. Density estimation and dispersion of green
cloverworm eggs in soybean. M.S. Thesis. Iowa State University,
Ames, Iowa.
Buntin, G. D and L. D. Pedigo. 1983. Seasonality of green cloverworm
(Lepidoptera: Noctuidae) adults and an expanded hypothesis of
population dynamics in Iowa. Environ. Entomol. 12(5): 1551-1558.
Burk, T. and C. 0. Calkins. 1983. Medfly mating behavior and control
strategies. Fla. Entomol. 66(1): 3-18.
Buschman, L. L., H. N. Pitre, C. H. Hovermale, and N. C. Edwards,
Jr. 1981a. Occurrence of the velvetbean caterpillar in
Mississippi: Winter Survival or Immigration. Environ. Entomol.
10(1): 45-52.
Buschman, L. L., H. N. Pitre, and H. F. Hodges. 1981b. Soybean
cultural practices: Effects on populations of green gloverworm,
velvetbean caterpillar, loopers and Heliothis complex. Environ.
Entomol. 10(5): 631-641.
Buschman, L. L., W. H. Whitcomb, T. M. Neal, and D. L. Mays.
1977. Winter survival and hosts of the velvetbean caterpillar in
Florida. Fla. Entomol. 60(4): 267-273.
Callahan, P. S. 1958. Serial morphology as a technique for
determination of reproductive patterns in the corn earworm,
Heliothis zea (Boddie). Ann. Entomol. Soc. Am. SI: 413-428.
Chapman, R. F. 1971. The insects: Structure and function.
American Elsevier Pub. Co. Inc., New York City, NY. 819 pp.
Chittenden, F. H. 1905. The caterpillar of Anticarsia gemmatalis
injuring velvetbean. USDA Bur. Entomol. Bull. 54: 77-79.
Daniel, C. and F. S. Wood. 1980. Fitting equations to data, computer
analysis of multifactor data. John Wiley and Sons. New York, NY.
Doss, B. D., R. W. Pearson, and H. T. Rogers. 1974. Effect of soil
water stress at various growth stages of soybean yield. Agron.
J. 66: 297-299.
Douglas, W. A. 1930. The velvet bean caterpillar as a pest of
soy beans in southern Louisiana and Texas. J. Econ. Entomol.
23(4): 684-690.
Douthwaite, R. J. 1978. Some effects of weather and moonlight on
light-trap catches of the armyworm, Spodoptera exempta (Walker)
(Lepidoptera: Noctuidae), at Muguga, Kenya. Bull. Entomol. Res.
68: 533-542.


Table D.7 (continued)
Vapor
Calendar
Date
Julian
Date
Flight
Temp. (C)
Press.
Deficit
(mm Hg)
Moonlight
Intensity
Wind
Speed
(m/s)
Wind
Direction
Rainfall
Barometric
Press. (MB)
Oct. 10
283
9.49
1.008
.0927
.592
120.0
.0000
1016.63
11
284
6.61
1.452
.1334
2.385
104.0
.0000
1018.64
12
285
3.27
1.928
.9306
2.201
107.7
.0000
1020.12
13
286
3.44
1.649
.8004
2.553
102.9
.0000
1020.58
14
287
3.10
.794
.7866
2.551
104.6
.0000
1021.38
15
288
.00
.741
.5525
.116
93.7
.0000
1018.32
231


130 -
estimates. Relative and absolute estimates of adult densities were
collected in 1981 and 1982 and were used for model construction,
parameterization, and model validation. Dissection data of adult
females indicated that the majority of females in the field were
potentially highly reproductive. These data were used to estimate the
proportion of mated females in the field. Proper identification of VBC
eggs and knowledge of egg developmental rate stipulated explicitly the
temporal occurrence of egg sampling and allowed for the determination of
absolute density estimates of freshly-laid eggs in the field (see
Chapter V). Freshly-laid eggs were one day old or less.
Model Assumptions
Model assumptions are listed below:
(1) There is a linear relationship between the total number of females
captured in the blacklight trap and the total number of females in
the field.
(2) All females are able to mate.
(3) There is no mortality of mated females prior to oviposition.
(4) There is no mortality of eggs during the first day after
oviposition.
(5) Ovipositional rate is the same for all females.
(6) Ovipositional rate is influenced by soybean phenological stage.
(7) Site-specific environmental conditions do not influence capture of
adults in the blacklight trap.
Model Conceptualization
A conceptual model of adult and egg dynamics is shown in Fig. 6.1.
A series of state variables are represented by acronyms shown in boxes
in Fig. 6.1. The state variables represent the numbers of individuals


136 -
than the other stages (35 and 18 days, respectively) and were
partitioned into separate SOY values.
The linkage expressed between ovipositional rate and soybean
phenology in the OVI function constrains the model to give predicted egg
density values only if soybean is available. This linkage allows for
interaction between VBC and soybean. Biological justification, or
support, for the oviposition values in this function are discussed below
in the model behavior section. Use of the OVI function requires that
soybean phenological stage be converted into SOY values for each
simulated data set.
Function for Total Egg Number
The total number of eggs in the field (TEGG) is represented by the
function:
TEGG = (M )(OVI),
r
where M and OVI are the same as described earlier.
r
Function for Predicted Egg Density
The predicted mean number of eggs laid per .91 m-row of soybean
(PEGG) is represented by the function:
PEGG = TEGG/ROW,
where TEGG equals the total number of eggs laid in the field and ROW
equals the total number of .91 m-row of soybean in the field.
Model Behavior
Although all models are an abstraction of reality, their behavior
should be consistent with observations made on the real system (Stimac
1977, Overton 1977). Desired model behavior can be specified explicitly
in the behavioral criteria of a model objective. The degree to which a
model meets these behavioral criteria dictates how well model


PAGE
Table 4.6.
Regression equations of physical variables and
weighted numbers of males, females, and adults
of the velvetbean caterpillar. Moths were
caught in a blacklight trap at the Green Acres
Research Farm, Alachua County, FL 107
Table 4.7.
Regression equations of total daily number of
velvetbean caterpillar moths in the field and
total nightly number of moths caught in the
blacklight trap during 1982 at the Green Acres
Research Farm, Alachua County, FL. Total number
of moths (females, males, and total adults) were
determined with adult trap-cage data 109
Table 4.8.
Regression equations of total daily number of
velvetbean caterpillar moths in the field and
total nightly smoothed number of moths caught in
the blacklight trap (BLT) during 1982 at the
Green Acres Research Farm, Alachua County, FL.
Total number of moths (females, males, and total
adults) were determined with adult trap-cage
Table 5.1.
Mean developmental time of speckled, brownish,
and hatched velvetbean caterpillar eggs at two
different temperatures. Colony (1982) and wild
(1983) females were used in the study 119
Table 5.2.
Mean developmental time and rate (SE) for
speckling to occur in VBC eggs from colony
females at six different temperatures. Mean
number of degree-hours required for speckling
(thermal constant) was 153.27 120
Table 5.3.
The total number of degree-hours accumulated
between sunset (onset of oviposition) and
plant sampling during each sample date in 1981
and 1982. Mean number of degree-hours required
for speckling to occur in VBC eggs is 153.27 123
Table 6.1.
Parametric values of ovipositional rate and SOY
used in the oviposition function of the adult
and egg population model of velvetbean caterpillar.
Values are based on data collected in 1982 and
model simulations IBS
xv


270 -
Unknown Species
Common Name:
Unknown.
Family:
Noctuidae (?).
Egg Development,
Color-Changes and Types:
Parasitoid Emerged
.. Black with hole in egg [Fig. E.9(A)]
Egg Shape: Top View
.. Circular.
Side View
.. Not recorded.
Ridge Number:
28, n = 1.
Ridge Morphology:
Distinct, easy to count.
Micropylar Area:
Depressed.
Spatial Occurrence:
Egg laid singly.
Similar Eggs and Differences:
Unknown.


155
Table A.l. Agronomic practices from 1980-1982 in a soybean field at Green Acres Research Farm, Alachua
County, FL.
Year
Description
1980
1981
1982
Field Size (ha)
.88
.82
.87
Number of Rows
112
102
110
Row Length (m)
103.35
107.00
103.66
Previous Winter Cover Crop
Unknown
Rye Grass
Rye Grass & Lupine
Pre-Plant Herbicide (ml/ha)
585, Surflan
585, Treflan
1169, Treflan
877, Lexone
877, Sencor
877, Lexone
Muriate of Potash (kg/ha)
258
111
104
Planting Date
June 3
June 12
June 9
Soybean Variety
Bragg
Bragg
Bragg
Row Spacing (m)
.76
.76
.76
No. of Plants/.91 row-m,
Sample Date
10, June 3
28.267, July 24
12.733, August 9


Table D.3 (continued)
Calendar
Date
Julian
Date
Number of
Females
Number of
Males
Number of Total
Adults
Total
Smoothed
Weighted
Total
Smoothed
Weighted
Total
Smoothed
Weighted
Sept. 17
260
31
37.29
-0.17
28
26.08
0.07
59
60.47
-0.02
18
261
39
32.69
0.19
14
25.45
-0.45
53
56.59
-0.06
19
262
29
29.00
0.00
35
24.89
0.41
64
53.09
0.21
20
263
24
26.82
-0.11
19
24.19
-0.21
43
50.58
-0.15
21
264
27
25.26
0.07
23
23.36
-0.02
50
48.33
0.03
22
265
28
23.87
0.17
37
23.14
0.60
65
46.22
0.41
23
266
15
23.46
-0.36
5
23.25
-0.78
20
45.53
-0.56
24
267
13
23.71
-0.45
9
23.25
-0.61
22
45.78
-0.52
25
268
38
23.84
0.59
38
23.25
0.63
76
45.91
0.66
26
269
46
24.06
0.91
42
23.36
0.80
88
46.98
0.87
27
270
3
24.50
-0.88
7
23.78
-0.71
10
49.13
-0.80
28
271
10
27.84
-0.64
12
25.14
-0.52
22
54.42
-0.60
29
272
35
34.38
0.02
23
28.38
-0.19
58
64.03
-0.09
30
273
57
38.09
0.50
82
31.84
1.58
139
70.60
0.97
Oct. 1
274
v 60
37.88
0.58
53
33.14
0.60
113
71.72
0.58
2
275
23
34.56
-0.33
24
30.04
-0.20
47
64.98
-0.28
3
276
23
29.06
-0.21
20
23.27
-0.14
43
51.33
-0.16
4
277
26
25.82
0.01
15
18.11
-0.17
41
42.93
-0.04
218


74 -
The temporal occurrence of feeding by unsexed adults was reasonably
uniform throughout the night [see Fig. 3.2(G) and Appendix C, Table
C.13]; unsexed adults flew out of sight before a positive sexual
identification could be made. The uniform inability to sexually
identify adults indicates no temporal bias occurred in identification of
unsexed adults during scotophase. The occurrence of feeding by all
adults (males, females, and unsexed) differed noteable for hours five,
eight, and twelve [see Fig. 3.2(H) and Appendix C, Table C.14]. These
hours corresponded, respectively, to peaks in male (aggregated) and
female feeding and to no feeding at all. The feeding occurrence of
males (not aggregated), females, and unsexed adults was different,
particularly for the eighth hour, which corresponded to peak female
feeding [see Fig. 3.2(1) and Appendix C, Table C.15]. Overall, feeding
by VBC adults occurred at all hours of the night (except for the 12th
hour).
Predators
Spiders were the only observed predators of VBC adults. No effort
was made to identify all the spider species at the study site or to
obtain density estimates of the recorded spider predators. Peucetia
viridans (Hentz) and Misumenops spp. were the most frequently observed
spiders. Peucetia viridans was found throughout the field (edge and
interior), usually on dicotyledonous plants and high above the ground
(ca. 1 m or higher). Misumenops spp. were found only at the field edge,
usually on monocotyledonous plants and close to the ground (ca. .5 m or
less). Most of the orbweavers were found at the field edge, with webs
at a height between ca. .5 and 1.5 m.
Six species of spiders were recorded as predators, with 26
predation records (see Table 3.9); all records were obtained during


73 -
when ca. 60% of all aggregated males were observed. Interestingly,
almost all mating (79.25%) occurred in the first four hours after
sunset, but the adaptive significance of the temporal relationship
between mating and aggregating is obscure.
Feeding by non-aggregated males occurred throughout scotophase,
except for the seventh hour when no feeding was recorded [Fig. 3.2(D)
and Appendix C, Table C.10]. Feeding by males probably occurred in the
seventh hour but only four observational periods were completed at this
time. The temporal occurrence of feeding by all males (aggregated and
non-aggregated) was non-uniformly distributed throughout scotophase, as
ca. 82% occurred within the first 6 h after sunset [see Fig. 3.2(D) and
Appendix C, Table C.11]. This non-uniform distribution was dominated by
the fifth post-sunset hour (43.65%) when large numbers of males
aggregated. Leppla (1976) found that colony males fed uniformly
throughout scotophase.
The temporal occurrence of feeding by females was non-uniformly
distributed, as 74.67% occurred between hours 5 and 11 post-sunset [see
Fig. 3.2(F), Appendix C, Table C.12]. The sample mean of hour 8
accounted for 32% of all female feeding, but why is unknown.
Interestingly, the first four hours post-sunset appeared to be devoted
to mating and oviposition when 79.25% and 84.72% of each activity
occurred, respectively. Females apparently partitioned their time
between feeding, mating, and ovipositing and may have acquired an
increased reproductive fitness from this partitioning (i.e., ovipositing
and mating during early scotophase may be more beneficial than feeding).
Leppla (1976) found that colony females fed throughout scotophase but
that feeding increased during the second half of scotophase.


Figure 3.5. Aggregation of velvetbean caterpillar males on the screen of an insectary. Males are
feeding at the surface of the screen. Photograph was taken at the edge of a 1 ha soybean
field at the Green Acres Research Farm, Alachua County, FL, September 14, 1983.


201
Table C.15. Sample mean and standard error of weighted
observations of feeding by males (excluding
aggregations), females, and unsexed velvetbean
caterpillar adults grouped by post-sunset hour,
along with the percent normalized sample mean and
standard error. Observations were made from
1980-82 at the Green Acres Research Farm, Alachua
County, FL, in a 1 ha soybean field.
Hour After
Sunset
b
n
Sample Mean of
the Weighted
Observations
( SE)
c
Percent Normalized
Sample Mean
( SE)
1
19
.0399 .0171
6.08
2.61
2
19
.0498 1 .0166
7.59
2.54
3
16
.0577 .0229
8.79
3.49
4
13
.0850 .0183
12.95
2.79
5
10
0766A .0216
11.67
3.30
6
5
0741A .0509
11.28
7.75
7
4
.0250 .0250
3.81
3.81
8
3
.1458 .0515
22.21
7.84
9
10
.0433 .0218
6.60
3.31
10
24
.0366 .0114
5.58
1.74
11
22
.0227 .0084
3.45
1.28
12
6
.0000 .0000
.00
.00
Unsexed adults flew out of sight before a positive sexual
identification could be made.
^n = number of weighted observations per sample mean; n is not
the number of feeding observations. See Table C.8 for a
complete listing of all observations and observational times.
Percent normalized sample mean = (sample mean of weighted
observations/0.656414)*100. Percent normalized standard error
= (standard error of weighted observations/0.656414)*100.


17
et al. (1973) present the most detailed observations, but their data
were collected over a short, seven-day time period. Johnson et al.
(1981) report a behavioral study on the response of VBC to its
pheromone. Heath et al. (1983) elucidate the chemical composition of
VBC pheromone and the pheromonal effect on male and female behavior.
Leppla (1976) and Leppla et al. (1979) indicate the circadian rhythms of
locomotion and reproductive behavior of adults in the laboratory. Wales
et al. (1985) demonstrate the flight and ovipositional dynamics of adult
females during tethered flight.
Host Plants
At least 40 legumes and five non-legumes appear to serve as host
plants for larvae of the VBC (Table 2.4). The authenticity of many of
the records in Table 2.4 is questionable because they were not
accompanied with (1) host scientific name, (2) confirmation of
oviposition, (3) verification of complete larval development, (4)
verification of larval and host identities, and (5) multiple sightings.
Based on these records VBC probably is restricted to leguminous host
plants and is therefore either monophagous (see Krieger et al. 1971) or
oligophagous (see Slansky 1976).
Velvetbean caterpillars appear to have a marked preference for
soybean over other hosts. Douglas (1930) states that neither larvae nor
feeding damage was sighted, except on soybean, in fields planted with
soybean and the following crops: cotton,* kudzu, cowpea, and
velvetbean. Hinds and Osterberger (1931) note a similar preference for
soybean grown with velvetbean, cowpea, and other legume crops (names
*Some larvae crawled from completely defoliated soybean to cotton and
fed on the cotton. Complete larval-development on the cotton was not
assessed.


Table 3.5. Observational records of feeding by adult velvetbean caterpillar during photophase at the Green
Acres Research Farm, Alachua County, FL, from 1980-83.
Date
Time of
Sunset
Time of
Observation
Time Before
Sunset (h/min)
Number of
Adults
Adult Sex3
Food Source*5
19 September 1980
1930
1900
0/30
2
Adult
Horse Mint
20 September 1980
1928
1900
0/28
2
Adult
Horse Mint
24 September 1982
1923
1900
0/23
2
Adult
Hairy Indigo
02 October 1982
1914
1515
3/59
1
Female
Hairy Indigo
2
Adult
Hairy Indigo
02 October 1982
1914
1535
3/39
1
Male
Hairy Indigo
08 November 1983C
1739
1730
0/09
2
Female
Common Beggar Tick
Sexually unidentified moths are listed as adult.
**The food source was always at a flower.
Horse Mint is Monarda punctata L.
Hairy Indigo is Indigofera hirsuta L.
Common Beggar Tick is Bidens alba (L.) DC.
c
Observed on the campus of the University of Florida, Gainesville, FL.


135 -
Table 6.1. Parametric values of ovipositional rate and SOY used in the
oviposition function of the adult and egg population model
of velvetbean caterpillar. Values are based on data
collected in 1982 and model simulations.
Length of3
Soybean Stage
(Days)
Soybean
Phenological
Stage
SOY Value0
Oviposition^
Rate
VE, VC
1
0
4
VI
1
0
4
V2
2
0
4
V3
3
0
3
V4
4
0
7
V5
5
0
4
V6
6
40
3
V7
7
40
4
V8
8
40
-
V9
9
40
4
V10
11
220
7
Rl, R2
11
220
11
R3
12
220
3
R4
13
220
7
Early R5
14
220
18
Mid R5
15
80
10
Late R5
16
210
7
Early R6
17
210
10
Late R6
18
60
3
R7
19
60
1
R8
20
0
A hyphen means that the corresponding soybean phenological stage must
have occurred but was not observed in the field.
See Fehr and Caviness (1977) or Tables 2.1 and 2.2 for a complete
description of these stages. In the stage descriptions "V" refers to
vegetative and "R" refers to reproductive.
c
Values of the parameter SOY were based on modifications of the Fehr and
Caviness (1977) system for determination of soybean phenological stage.
See the text for a discussion of SOY values.
Ovipositional rate is the total number of eggs oviposited per female
per night on soybean.


progress were always helpful and encouraging. Ken's boundless energy
and enthusiasm have been enjoyed and admired.
I owe special thanks to Don Herzog. Without his financial support
and friendship my program would have been very difficult to complete, if
not impossible. His constant support and encouragement over the years
have always been appreciated. I envy anyone that has the opportunity to
work and interact with Don.
I also owe special thanks to Strat Kerr for the tireless hours he
spent coordinating my graduate activities and for financially supporting
me during some rough times. He constantly went out of his way for me
and liberally interpreted bureaucratic rules that made life a lot easier
for me. The students in the department are lucky to have Strat's
guidance, help and concern.
I would like to thank Norm Leppla for providing me with laboratory-
reared velvetbean caterpillar larvae over the years. Our many
discussions about science, life and women (not necessarily in that
order) have been illuminating. Norm is a good friend.
Pat Greany has a wonderful personality and I am indebted to him for
his photographic expertise. I learned a lot from Pat and I appreciate
the many hours he took to help me with my research.
I thank Everett Mitchell for loaning me his blacklight traps.
Everett's field knowledge was invaluable for the success of my project
and he always had time to listen to my ideas and to help me with their
fruition.
I will miss the frequent discussions I had with Jon Allen. He
constantly stimulated my thoughts about quantitative ecology and taught
me how to convert complex problems into easy problems that could be
readily solved. His views about life have been illuminating.
- vi -


- 241
Anticarsia gemmatalis Hubner
Common Name: Velvetbean Caterpillar.
Family: Noctuidae
Egg Development,
Color-Changes and Types:
Freshly Laid Light green, green, bluish green,
turquoise, or off white [Fig. E.l(A)].
Middle Aged Same as freshly laid but with speckles.
Speckles are small, irregular in shape
and reddish brown, brownish red, ochre
or (rarely) off white [Fig. E.l(B)].
After speckling occurs larvae develop
an eye spot (i.e., six stemmata) that
is visible at the edge of the
micropylar area [Fig. E.l(C), see tiny
dark brown spots that form a small
crescent].
Old (Pre-Eclosion) Light brown with a visible larval
head-capsule, eyes and mandibles [Fig.
E.l(D)].
Eclosed Whitish [Fig. E.l(E)]. Usually the
chorion was eaten by a larva.
Parasitized Black [Fig. E.1(F and G) ].
Black with hole in egg [Fig. E.l(H)].
Parasitoid Emerged


Table D.7 (continued)
Calendar
Date
Vapor
Press.
Julian Flight Deficit Moonlight
Date Temp. (C) (mm Hg) Intensity
Sept. 23
266
7.73
1.249
.0093
24
267
5.41
2.469
.0051
25
268
8.05
2.701
.0000
26
269
6.11
.846
.0008
27
270
7.17
1.049
.0000
28
271
6.11
1.425
.0000
29
272
8.56
1.768
.0000
30
273
5.32
1.440
.0025
Oct. 1
274
6.29
1.973
.0033
2
275
6.62
4.281
.0066
3
276
4.16
1.439
.0126
4
277
8.93
2.777
.0243
5
278
6.16
2.299
.0392
6
279
5.74
1.395
.0633
7
280
10.37
3.233
.0319
8
281
8.33
2.452
.0126
9
282
9.86
1.314
.0664
Wind
Speed Wind Barometric
(m/s) Direction Rainfall Press. (MB)
.450
125.9
.0000
1019.55
1.451
140.4
.0000
1022.64
1.919
132.6
.0000
1020.88
-
-
.0000
1020.39
.374
105.9
.0000
1019.23
.366
107.7
.0000
1018.56
.864
139.8
.0000
1019.56
.324
129.0
.0000
1019.98
.229
118.1
.0000
1016.20
1.100
96.7
.0000
1012.88
1.561
107.7
.0000
1017.62
.889
161.6
.0000
1020.01
.644
142.1
.0000
1020.36
.144
140.0
.0000
1015.79
.259
128.1
.0000
1011.93
1.753
153.2
.0000
1015.11
.644
131.5
.0000
1016.87
230


Table 3.8. Number of adult males of the velvetbean caterpillar feeding in a soybean field at
Green Acres Research Farm, Alachua County, FL, from 1980-82. Also, number of males
per aggregate, number of aggregates, and description of food site are provided.
No. of3
Males Feeding
No. of Males^
Per Aggregate
No. ofC
Aggregates
Description of Food Site^
5
0
0
Human Skin
4
0
0
Vinyl Raincoat
1
0
0
White Cotton Pants
1
0
0
Aluminium Push Button, Head Lamp
1
3
0
0
Bamboo Sticks
ON
123
29, 22, 18, 17, 12,
9, 5, 3, 3, 3
10
Aerial and Sweep Nets (Bag and Pole)
1
16
15
1
Black Saran Screen
24
15, 5, 3
3
Brown Saran Screen
2
0
0
Barb Wire Fence
aTotal Male Feeding = 179.
^Total Males in Aggregates = 159.
c
Total Aggregates = 14.
^Males fed at the surfaces of food sites.


Anticarsia gemmatalis Hubner
A
Wing Span
35-40 mm (Forbes 1954).
Dorsal Wing Surface
Forewing and hindwing: Basic wing coloration is extremely variable
and ranges from ashen gray to light yellowish-brown to reddish-brown
(Watson 1916a, Forbes 1954, Kimball 1965, Leppla et al. 1977). Wing
pattern is mottled and shaded, and wing-mark colorations are highly
variable and include black, white, gray, brown, and ochre [Fig. B.1(A
and C)].
Forewing: The postmedial line is distinctive and runs obliquely
from the wing apex to the approximate middle of the anal margin [Fig.
B.1(A and C), letter a]. The reniform spot on each forewing is large,
irregular, pale, and usually faint (sometimes obscure)[Fig. B.1(A and
C), letter b].
Hindwing: The postmedial line is distinctive and runs essentially
parallel to the outer margin [Fig. B.1(A and C), letter c].
Postmedial line: The postmedial line is distinctive and runs
obliquely from the apex of the forewing to the approximate middle of the
anal margin of the hindwing [Fig. B.1(A and C), letters a and c].
Ventral Wing Surface
Forewing and hindwing: Wing color is light brown or cinnamon brown
(Watson 1916a). Wing pattern is shaded and wing-mark colorations are
restricted to various shades of brown and white. The subterminal line
161


197
Table C.ll. Sample mean and standard error of weighted
observations of feeding velvetbean caterpillar
males (all males) grouped by post-sunset hour,
along with the percent normalized sample mean and
standard error. Observations were made from
1980-82 at the Green Acres Research Farm, Alachua
County, FL, in a 1 ha soybean field.
Hour After
Sunset
a
n
Sample Mean of
the Weighted
Observations
( SE)
Percent Normalized^
Sample Mean
( SE)
1
19
.0309 .0142
4.56
2.09
2
19
.0492 .0234
7.26
3.45
3
16
.0865 .0346
12.75
5.10
4
13
.0659 .0281
9.72
4.15
5
10
.2961 .1591
43.65
23.46
6
5
.0302 .0247
4.45
3.64
7
4
.0000 .0000
.00
.00
8
3
.0878 .0639
12.95
9.42
9
10
.0142 .0077
2.10
1.13
10
24
.0093 .0045
1.37
.64
11
22
.0081 .0031
1.19
.45
12
6
.0000 .0000
.00
.00
3n = number
of weighted observations per
sample mean; n
is not
the number
of feeding observations. See
: Table C.8 for
a
complete listing of all observations and observational times.
i
Percent normalized sample mean = (sample mean of weighted
observations/0.678208)*100. Percent normalized standard error
= (standard error of weighted observations/0.678208)*100.


predict the number of ovipositing females in the field. The capture of
adults in the blacklight trap (BLT) coincided with the appearance of
eggs in the field, while adult residency in the field appeared to be
delayed until an appropriate vapor pressure deficit had been reached in
the field. Dissections of adult females revealed that most females
were mated and contained large amounts of fat body. Select physical
variables were explored with multiple linear regression for their effect
on blacklight trap catch but no consistently adequate correlations were
uncovered.
Velvetbean caterpillar eggs were shown to be polychromatic during
development. These color changes were temperature-dependent and were
used to age field collected eggs. Egg densities predicted by the model
were more accurate with a variable ovipositional rate as opposed to a
constant rate. The variable ovipositional rate was linked to changes in
soybean phenology. In model validation, 65% of the model's predicted
values fell within 95% confidence intervals of field estimates.
Differences between predicted and estimated values were attributed to
unpredictable fluctuations in BLT catch and to variation in
ovipositional rate between years.
xx


MEAN EGG DENSITY
Figure 6.4. Mean velvetbean caterpillar egg density per .91 m-row of soybean during 1981 in a 1 ha
field at the Green Acres Research Farm, Alachua County, FL. Estimated density with 95%
confidence intervals determined from field collected data. Upper and lower values of the
confidence intervals are represented as hyphens. Predicted density determined with model
simulations. Ovipositional rate was variable during the simulation.
143


26 -
Soybean and VBC interact in several ways: (1) oviposition by
moths, (2) foliage consumption by larvae, (3) nutritional quality of
plants, and (4) canopy dynamics of the plants. Soybean serves as an
ovipositional substrate (Greene et al. 1973), and differences in
infestation levels on some varieties may be due to an ovipositional
preference (see Genung and Green 1962). Soybean varieties and
phenological stages vary nutritionally (see Hammond et al. 1951,
Henderson and Kamprath 1970, Hanway and Weber 1971), and this variation
significantly affects VBC development, consumption, survivorship, and
reproduction (Moscardi et al. 1981a, Moscardi et al. 1981b, Reid 1975,
Oliveira 1981). Also, as larvae develop, their consumption rate
(cm2/day) increases: instar 2 = 0.31; instar 3 = 1.47; instar 4 = 3.94;
instar 5 = 8.11; and instar 6 = 14.39 (Reid 1975).
The dynamics of the soybean canopy have an enormous effect on two
aspects of VBC dynamics: (1) adult colonization and (2) larval
mortality. Colonization by adults may be related to changes in soybean
canopy (see Chapter IV). Canopy dynamics affect larval mortality in
four ways. First, canopy closure establishes favorable microclimatic
changes that can lead to an epizootic of Nomuraea rileyi (Farlow)
Samson, an entomopathogenic fungus (Kish and Allen 1978). Second,
mortality rates of immature VBC that have fallen to the ground are
significantly higher before the canopy closes due to high soil surface
temperature (Elvin 1983). Third, canopy leaf area is a key element in
the predator/prey dynamics of VBC larvae. Leaf-area increase provides a
spatial escape for VBC larvae (ONeil 1984). Fourth, female moths
appear to oviposit on the lowest two-thirds of the plant and small
larvae are apparently distributed in the bottom third of the canopy (see
Ferreira and Panizzi 1978). Mortality of eggs and small larvae may


88 -
values of BLT catch were determined with the equation:
WBLT = (RBLT SBLT)/(SBLT),
where WBLT = weighted blacklight trap catch,
RBLT = raw blacklight trap catch, and
SBLT = smoothed blacklight trap catch.
Weighted values of BLT catch represent the change in the proportional
magnitude of moths captured per night in the BLT. Smoothed values were
determined with a nonlinear data smoothing algorithm (3RSSH, twice)
based on running medians (see Velleham 1980, Ryan et al. 1982). Three
variable selection procedures were utilized: forward selection,
backward elimination, and maximum r2 improvement (i.e., forward
selection with pair switching). Models were selected based upon
parameter significance, residual plots, r2, and Mallows' Cp statistic
[for discussions of Cp see Mallows (1973) and Daniel and Wood (1980)].
Results and Discussions
Blacklight Trap
The total number of females, males, and adults (females and males)
captured per night (1980-82) in the BLT are shown in Fig. 4.2 (A-C) and
listed in Appendix D, Tables D.1-D.3. Comparisons of the number of
captured moths among years are difficult to make because of (1)
differences in BLT sizes, (2) electrical problems with the '80 BLT that
resulted in no catch during 9 nights, and (3) variation in the temporal
occurrences of trappingthe BLT ran for 71 days in '80, 116 days in
'81, and 123 days in '82. Nevertheless, initially-captured adults were
females in '80, males in '81, and both sexes in '82. Apparently, both
sexes make initial flights into soybean. Adult density during July and
August (Julian date 182 to 243) varied considerably among years. In
1981, BLT catch was depressed as only 698 adults were captured. In '80


Table D.2 (continued)
Number of Females
Number of Males
Number of Total
Adults
Calendar
Julian
Date
Date
Total Smoothed Weighted
Total Smoothed Weighted
Total Smoothed
Weighted
Oct. 5
278
34
33.81
0.01
41
38.00
0.08
75
70.50
0.06
6
279
33
33.50
-0.01
38
38.00
0.00
71
71.00
0.00
7
280
23
33.25
-0.31
18
37.50
-0.52
41
71.00
-0.42
8
281
36
32.75
0.10
49
36.50
0.34
85
71.00
0.20
9
282
35
29.38
0.19
36
33.75
0.07
71
65.00
0.09
10
283
20
20.38
-0.02
27
29.25
-0.08
47
53.00
-0.11
11
284
6
11.50
-0.48
9
23.25
-0.61
15
40.25
-0.63
12
285
9
8.25
0.09
47
15.75
1.98
56
26.75
1.09
13
286
8
8.00
0.00
12
12.00
0.00
20
20.00
0.00
14
287
1
8.00
-0.88
10
12.00
-0.17
11
20.00
-0.45
15
288
11
8.00
0.38
17
12.00
0.42
28
20.00
0.40
£
Total numbers were smoothed with a nonlinear data-smoothlng algorithm (3RSSH, twice) based on running
medians (see Velleman 1980, Ryan et al. 1982).
Weighted Total # = (Total # Smoothed #)/(Smoothed //) .
212


152 -
variations in ovipositional rate appeared to be related to higher than
normal canopy VPD caused by drought periods.
Differences in model behavior between 1981 and 1982 indicated that
structural modifications in the model should produce more desirable
model behavior. Model behavior should be improved by writing
mechanistic equations that account for fluctuations in BLT catch and
variation in ovipositional rate. Attainment of these mechanistic
equations will depend on the collection of additional data on adult and
egg numbers and on identification and quantification of those
environmental variables that affect BLT catch and oviposition. For
example, wind tunnel tests could be used to quantify the impact of wind
speed on adult flight. Also, experimental evidence of a variable
ovipositional rate should be acquired and quantified.
The adult and egg population model developed in this study should
be incorporated into the VBC dynamics model, as equations that describe
adult influx in the dynamics model are not based on field collected
adult density estimates. Determination of the robustness of the
population model awaits the collection of additional data on adult and
egg numbers and an evaluation of the model's behavior with these data.
These data should be collected at numerous sites to examine variation in
the effect of site specific environmental conditions. Also, an analysis
of model behavior with the model as part of the overall dynamics model
should be completed.
Overall, the present study has provided the framework, manifested
as a model, necessary to measure the intra-field dynamics of a noctuid
moth. This framework can serve as template for other researchers who
seek to develop a quantitative relationship between adult and egg


196 -
Table C.10. Sample mean and standard error of weighted
observations of feeding velvetbean caterpillar
males (not in aggregations) grouped by post-sunset
hour, along with the percent normalized sample
mean and standard error. Observations were made
from 1980-82 at the Green Acres Research Farm,
Alachua County, FL, in a 1 ha soybean field.
Sample Mean of
b
the Weighted
Percent Normalized
Hour After
Observations
Sample Mean
Sunset
3.
n
( SE)
( SE)
1
19
.0204
+
.0107
9.48
+
4.98
2
19
.0185
+
.0085
8.61
+
3.96
3
16
.0237
+
.0107
11.03
+
4.97
4
13
.0369
+
.0112
17.14
+
5.22
5
10
.0165
+
.0101
7.66
+
4.67
6
5
.0302
+
.0247
14.05
+
11.48
7
4
.0000
+
.0000
.00
+
.00
8
3
.0373
+
.0188
17.34
+
8.76
9
10
.0142
+
.0077
6.61
+
3.56
10
24
.0093
+
.0045
4.43
+
2.09
11
22
.0081
+
.0031
3.76
+
1.43
12
6
.0000
+
.0000
.00
+
.00
n = number of weighted observations per sample mean; n is not
the number of feeding observations. See Table C.8 for a
complete listing of all observations and observational times.
^Percent normalized sample mean = (sample mean of weighted
observations/0.215046)* 100. Percent normalized standard error
= (standard error of sample mean/0.215046)*100.


Table D.4 (continued)
Julian
Date
238
245
252
Total Number
Sample
Number Females Males Adults
Total Number
Julian Sample
Date Number Females Males Adults
259 1
2
3
4
5
6
0 0 0
4 1 5
4 0 4
1 2 3
1 1 2
0 3 3
266 1
2
3
4
5
6
0
0
2
2
7
0
1
1
0
3
2
0
1
1
2
5
9
0
i
273 1
2
3
4
5
6
2 0 2
0 0 0
0 5 5
0 0 0
0 0 0
1 0 1
222


262 -
Figure E.5 (continued)


A detailed explanation and an example of the quantitative
technique, for analysis of observational data on oviposition, mating,
and feeding, are presented. Data in Tables C.l and C.2 are artificial
for ease of discussion. In Table C.l, data are presented on number of
observations, observation times, and weighted observations. The
observational time of hour 1 is 30 min, and the number of observations
of the activity is 1. The weighted observation for hour 1 is .03; one
observation divided by 30 min equals .03. Six observations occur during
hours 2 and 3. Based on the number of observations for hours 2 and 3,
the activity is equally prevalent during each hour. This equality is
misleading because 60 min were required to make the observations in hour
2, while 30 min were required in hour 3; i.e., twice as much time was
spent in hour 2 to see the same number of observations. The weighted
observations for hours 2 and 3 are .10 and .20, respectively. The value
for hour 3 is twice as large as the value for hour 2. The difference
between the weighted values for the two hours properly reflects the
differences in observational time between the two hours.
In Table C.2, data are presented on weighted observations, sample
means, normalized means, and percent normalized means. Data are grouped
by hour after sunset, irregardless of year, month, and day. For hour 1,
the sample mean of the weighted observations is determined as follows:
.03 + .01 + .02 = .06/3 = .02. The sum of the sample means for all 12
hours is .82. Each sample mean is normalized by division with .82. The
normalized sample means add up to the value of one. A percent
normalized sample mean is obtained by multiplying the appropriate
normalized sample mean by 100.
168 -


3 Id c
Table 5.1. Mean developmental time of speckled brownish and hatched velvetbean caterpillar eggs
at two
study.
different
temperatures.
Colony (1982)
and
wild (1983) females
were
used in the
Speckled Eggs^
Brownish Eggs^
Hatched Eggs^
Female
No. of
Temp.
n
x SE
n
x SE
n
x SE
Source
Females
(C)
(h)
(h)
(h)
Colony
4
23.9
73
18.9 .23A
67
106.8 .38D
65
117.2 .44G
Colony
3
26.7
65
13.3 .26B
65
60.7 .21E
61
67.1 .24H
Wild
10
26.7
166
9.5 .07C
158
! 59.1 .14F
157
64.0 .151
2
Speckled refers to an egg that is typically light green with brownish-red speckles.
^Brownish refers to an egg that is light brown with a visible head-capsule,
c
Hatched refers to larval eclosin.
^Means followed by different letters are significantly different according to Kruskal-Wallis Test (a =
.05).
119


144 -
oviposition was depressed early in the 1981 season. Why is unknown, but
rainfall in early 1981 was very low and retarded soybean growth (see
Appendix A and Table 4.2). Perhaps VBC ovipositional rate was altered
in response to poor soybean growth or high VPD which would occur in a
drought-stressed crop. Field VPD in the day was very high during dates
200-210 and dropped below 4 mm Hg by date 216 [see Fig. 4.6(B)],
The two disagreements between predicted and estimated values at
dates 243 and 250 reflect a general depression in predicted egg density
from dates 243 to 256 (or R5). This depression resulted from an
ovipositional rate of 80 eggs per female per night as determined from
1982 model simulations. Replacement of this rate with 200 eggs per
female per night yields more acceptable behavior. Evidently, something
depressed ovipositional rate in the field during R5 in 1982 but not in
1981.
Conclusions
Addition of the adult and egg population model into the VBC
dynamics model would make the dynamics model more realistic. Equations
that describe adult and egg numbers in the current dynamics model are
based on relationships that were determined with estimated larval
densities. Therefore, changes in larval density are based on
assumed changes in adult influx. If larval densities are actually
sensitive to adult influx then changes in adult influx must be
demonstrated with experimental data and equations must be written that
are based on these data. These equations would add more realism to the
dynamics model.
Differences in model behavior between 1981 and 1982 indicate that
structural modifications with the model would be needed to achieve more


124 -
non-viable eggs would have yielded inflated estimates of egg density (as
both viable and non-viable eggs are initially the same color) and
strongly biased adult-to-egg conversions in the oviposition model (see
Chapter VI). With regard to mortality, previous studies (Elvin 1983)
allowed for the assumption that mortality of freshly-laid eggs at night
was minimal.
Mean densities of freshly-laid VBC eggs per .91 m-row in 1981 and
1982 are shown in Fig. 5.3. In 1981, egg density displayed a general
rise from late July (date 204) to mid-September (date 257). In 1982,
egg density demonstrated a general rise and fall through the season,
with two exceptions: (1) unexplainable drops in density occurred on
September 3 and 6 (dates 246 and 249) and (2) the wide confidence
interval at date 264 resulted from sampling a plant with 78 eggs. Why
there were so many eggs on this plant is unknown. Egg and adult
densities in both years tended to change synchronously (see Chapter IV).
Sample size, sample unit size, mean, and standard deviation of freshly-
laid eggs for all sample dates are listed in Appendix F.
Egg-Speckling Hypothesis
Speckled VBC eggs may be colored cryptically as a result of the
selective pressures of predators and parasites. Light-green eggs are
easy to see on soybean, while speckled eggs are extremely difficult to
see. Light-green eggs laid during early scotophase speckle just after
sunrise and probably are difficult for predators to see. Light-green
eggs laid during late scotophase are still light-green after sunrise and
probably are easy for predators to see. Females that oviposit in early
scotophase should demonstrate a higher reproduction fitness over females
that lay eggs in late scotophase because (hypothetically) the sooner an
egg is laid after sunset the greater its chances of survival from


Table D.2 (continued)
Calendar
Date
Julian
Date
Number of
Females
Number of
Males
Number of Total
Adults
Total
Smoothed
Weighted
Total
Smoothed
Weighted
Total
Smoothed
Weighted
July 25
206
0
0.00
0.00
2
2.00
0.00
2
2.00
0.00
26
207
0
0.00
0.00
1
2.00
-0.50
1
2.00
-0.50
27
208
1
0.00
0.00
1
2.00
-0.50
2
2.00
0.00
28
209
1
0.00
0.00
3
2.00
0.50
4
2.00
1.00
29
210
0
0.00
0.00
2
2.00
0.00
2
2.00
0.00
30
211
0
0.00
0.00
3
2.00
0.50
3
2.00
0.50
31
212
0
0.00
0.00
1
1.81
-0.45
1
1.75
-0.43
Aug. 1
213
1
0.00
0.00
2
1.44
0.39
3
1.25
1.40
2
214
0
0.00
0.00
0
1.25
-1.00
0
1.00
-1.00
3
215
0
0.25
-1.00
2
2.19
-0.09
2
2.25
-0.11
4
216
1
0.75
0.33
5
4.94
0.01
6
5.75
0.04
5
217
1
1.25
-0.20
13
7.63
0.70
14
9.00
0.56
6
218
2
1.75
0.14
8
7.94
0.01
10
9.50
0.05
7
219
2
2.00
0.00
6
6.44
-0.07
8
8.25
-0.03
8
220
2
2.00
0.00
5
4.63
0.08
7
7.00
0.00
9
221
3
2.00
0.50
3
3.00
0.00
6
5.63
0.07
10
222
2
2.00
0.00
2
1.75
0.14
4
3.63
0.10
11
223
0
2.19
-1.00
0
1.50
-1.00
0
2.00
-1.00
208


290 -
Kimball, C. P. 1965. Arthropods of Florida and neighboring land
areas. Vol. 1. Lepidoptera of Florida. Division of Plant
Industry, State of FL, Dept, of Agr., Gainesville, FL.
Kish, L. P. and G. E. Allen. 1978. The biology and ecology of
Nomuraea rileyi and a program for predicting its incidence on
Anticarsia gemmatalis in soybean. Florida Agr. Exp. Sta. Tech.
Bull. 795: 1-48.
Kobayashi, M. and I. Tamura. 1939. Differences in the degree of
infestation by adult beetles of Anmala rufocuprea Motsch. of the
varieties of soybean. Rev. Appl. Entomol. Series A: Agricultural.
27: 210.
Kogan, M. 1975. Plant resistance in pest management, pp. 103-146.
In R.L. Metcalf and W.H. Luckman, eds. Introduction to insect pest
management. John Wiley and Sons, New York, NY.
Krieger, R. I., P. P. Feeny, and C. F. Wilkinson. 1971.
Detoxification enzymes in the guts of caterpillars: An
evolutionary answer to plant defenses? Science 172: 579-581.
Leppla, N. C. 1976. Circadian rhythms of locomotion and reproductive
behavior in adult velvetbean caterpillars. Ann. Entomol. Soc. Am.
69(1): 45-48.
Leppla, N. C., T. R. Ashley, R. H. Guy, and G. D. Butler. 1977.
Laboratory life history of the velvetbean caterpillar. Ann.
Entomol. Soc. Am. 70(2): 217-220.
Leppla, N. C., E. W. Hamilton, R. H. Guy, and F. L. Lee. 1979.
Circadian rhythms of locomotion in six noctuid species. Ann.
Entomol. Soc. Am. 72: 209-215.
Lewis, W. H. 1977. Ecology field glossary, a naturalist's vocabulary.
Greenwood Press, Westport, CT.
Linker, H. M. 1980. An analysis of seasonal abundance and sampling
procedures for the major defoliating lepidoptera in peanuts and
soybeans in north Florida. Ph.D. Dissertation. University of
Florida, Gainesville, FL.
Lloyd, J. E. 1981. Pragmatic insect behavioral ecology: A not-so-
odd-coupling. Fla. Entomol. 64(1): 1 -2.
Lockwood, J. A., T. C. Sparks, and R. N. Story. 1984. Evolution of
insect resistance to insecticides: A reevaluation of the roles of
physiology and behavior. Bull. Entomol. Soc. Am. 30(4): 41-51.
Lopez, Jr., J. D., A. W. Hartstack, Jr., J. A. Witz, and J. P.
Hollingsworth. 1979. Relationship between bollworm oviposition
and moth catches in blacklight traps. Environ. Entomol. 8(1):
42-45.


133 -
Function for Total Female Population
The total number of females captured in the blacklight trap is
converted into the field density of females based on the following
linear regression equation:
FTOTAL = 134.11 + 23.20 (FBLT),
where FTOTAL is the total number of females in the field, FBLT is the
total number of females captured in the blacklight trap, and 134.11 and
23.20 are the intercept and slope coefficients estimated from linear
least squares. The parameters were estimated using data collected
during 1982 at the Green Acres Research Farm (see Chapter IV for details
on data collection and analysis).
Functions for Mated Female Population and Mortality
Mated female population (M ) is determined with the following
r
function:
M = (FTOTAL) (l-VjCl-MORT),
r l4
where FTOTAL is the total number of females in the field, V is the
F
proportion of virgin females in the population and MORT is the
proportional mortality of mated females per night. The quantity (1-V )
is the proportion of mated females and the quantity (1-MORT) is the
proportional survival of mated females.
In the current version of the model, values for V and MORT are
F
assumed to be zero. There are several reasons why these variables are
set to values of zero. First, both can act in a compensatory fashion in
the present model form. Secondly, data on the number of virgin females
in the population are available only for 1981. These data values are
near zero during most of the field season. Thirdly, there are no data
on mortality estimates of adult females in the field. The current model
version has been used to identify these data deficiencies.


A MODEL OF ADULT AND EGG POPULATIONS
OF Anticarsia gemmatalis Hubner
(LEPIDOPTERA: NOCTUIDAE) IN SOYBEAN
By
BEN GREGORY, JR.
A DISSERTATION PRESENTED TO THE GRADUATE SCHOOL
OF THE UNIVERSITY OF FLORIDA IN
PARTIAL FULFILLMENT OF THE REQUIREMENTS
FOR THE DEGREE OF DOCTOR OF PHILOSOPHY
UNIVERSITY OF FLORIDA
1986


159
Table A.3 (continued)
Calender
Date
Julian
Date
Vegetative
Stage
Reproductive
Stage
Sept. 20
263
V14
R5
24
267
V14
R6
27
270
V14
R6
Oct. 1
274
V14
R6
4
277
V14
R6
8
281
V14
R6
11
284
V14
R7
15
288
V14
R8


295 -
USDA. 1954b. Cereal and forage insects. USDA Coop. Econ. Insect.
Rep. 4: 881-885.
van Schaik, P. H. and A. H. Probst. 1958. Effects of some
environmental factors on flower production and reproductive
efficiency in soybeans. Agron. J. 50: 192-197.
Velleham, P. F. 1980. Definition and comparison of robust nonlinear
data smoothing algorithms. J. Am. Stat. Assoc. 75: 609-615.
Vohden, R. A. and F. G. Smith, eds. 1982. The astronomical
almanac. U.S. Government Printing Office, Washington, D.C.
Waddill, V. 1981. Melilotus alba: A new host of the velvetbean
caterpillar(Note). Fla. Entomol. 64(4): 545.
Waddill, V. H., E. R. Mitchell, W. H. Denton, S. L. Poe, and D. J.
Schuster. 1982. Seasonal abundance of the fall armyworm and
velvetbean caterpillar (Lepidoptera: Noctuidae) at four locations
in Florida. Fla. Entomol. 65(3): 350-354.
Wales, P.J. 1983. Activity of velvetbean caterpillar moths as recorded
by a new actograph. M.S. Thesis. University of Florida,
Gainesville, FL.
Wales, P. J., C. S. Barfield, and N. C. Leppla. 1985. Simultaneous
monitoring of flight and oviposition of individual velvetbean
caterpillar moths. Physiol. Entomol. 10: 467-472.
Watson, J. R. 1915. Another migratory moth (Lep.). Entomological
News. 26(9): 419-422.
Watson, J. R. 1916a. Life-history of the velvet bean caterpillar
(Anticarsia gemmatalis Hubner). J. Econ. Entomol. 9(6): 521-528.
Watson, J. R. 1916b. The velvet bean caterpillar and its control.
Fla. Grower 13(5): 11-12.
Watson, J. R. 1916c. Control of the velvet bean caterpillar. Fla.
Agr. Exp. Sta. Bull. 130: 45-58.
Watson, J. R. 1921. The velvet bean caterpillar. Fla. Agr. Exp.
Sta. Press Bull. 325: 1-2.
Watson, J. R. 1932. Insects of the winter, 1931-32. Fla. Entomol.
15(4): 71-73.
Weiss, E. A. 1983. Oilseed crops. Longman Inc., New York, NY.
Wilkerson, G. G., J. W. Jones, K. J. Boote, K. T. Ingram, and J. W.
Mishoe. 1983. Modeling soybean growth for crop Management.
Trans. ASAE 26: 63-73.


- 296 -
Wilkerson, G. G., J. W. Mishoe, and J. L. Stimac. In press. Modeling
velvetbean caterpillar (Lepidoptera: Noctuidae) populations in
soybean. Environ. Entomol.
Wilkerson, G. G., J. W. Mishoe, J. L. Stimac, J. W. Jones, D. P.
Swaney, and W.G. Boggess. 1982. SICM: Florida soybean intergrated
crop management model: Model description and user's guide. Annu.
Rpt., Modeling Workshop, Soybean Project, Soybean CIPM, University
of Florida, Gainesville, FL.
Wille, J. E. 1939. Departmento de Entomolgia. Memoria del jefe del
Departmento. La Molina Estac. Exp. Agr. Mem. 12: 177-210.
Wolcott, G. N. 1936. "Insectae Borinquenses." A revision of
'"Insectae Portoricensis,' a preliminary annotated check-list of
the insects of Porto Rico, with descriptions of some new species,"
and "First supplement to Insectae Portoricensis." J. Agr. Univ.
Puerto Rico 20: 1-600.
Wolcott, G. N. 1948. The insects of Puerto Rico. J. Agr. Univ.
Puerto Rico 32(3): 1-975.


80 -
production. Males utilized some food sources that females did not use.
At these sources, males usually occurred in aggregations. Future
research efforts might examine more quantitatively the affect of adult
age, adult nutrition, host plant density and physiology, and weather
factors on flight, mating, oviposition, and feeding. Some of these
efforts might be accomplished by observing individual moths.
Observations of adult activities were density-dependent. Sightings
of mating, oviposition, feeding, and mortality were not observed in June
and July at low adult density, but were observed in August, September,
and early October at high adult density (see Chapter IV for adult
density data). In future studies of adult behavior, concentration of
observation time during high adult density should yield more behavioral
observations.
The present study has expanded our knowledge of VBC behavior and
provided information essential for the construction of a model of adult
and egg populations (see Chapter VI). Knowledge of the temporal
occurrence of flight and some environmental factors affecting flight
allowed for the development of an unique adult sampling method (and the
subsequent acquisition of adult density data) and a better understanding
of adult density fluctuations (see Chapter IV). Knowledge of the
temporal occurrence of oviposition allowed for the development of an
unique sampling method for eggs and the subsequent acquisition of egg
density data (see Chapter V). The measurements of adult and egg
densities are presented in the next two chapters. These density
measurements were necessary for model construction and validation (see
Chapter VI).


Table 3.9. Records of spider predation on adult velvetbean caterpillar (VBC) from 1980-83
at Green Acres Research Farm, Alachua County, FL, in a 1 ha soybean field. All
records occurred during scotophase.
Spider6 _
Spider Stage VBC
Date
(D-M-Y)
Time^
c
Location
Spider Scientific
Name4*
Common
Name
Spider
Family
and
Sex
Adult
Sex
19-S-81
2047
E.
Bahlagrass
Peucetla
vlrldans
(Hentz)
Green Lynx
Oxyopldae
*. +
M
19-S-81
2058
I.
Soybean
Peucetla
vlrldans
(Hentz)
Green Lynx
Oxyopldae
*, +
M
24-S-82
2112
I.
Florida Pasley
Peucetla
vlrldans
(Hentz)
Green Lynx
Oxyopldae
*, +
M
I7-S-81
2115
E,
Bahiagrass
Peucetia
vlrldans
(Hentz)
Green Lynx
Oxyopldae
*, +
F
19-S-83
2130
E.
Sandbur
Peucetla
vlrldans
(Hentz)
Green Lynx
Oxyopldae
A A

M
24-S-82
2147
I.
Soybean
Peucetla
vlrldans
(Hentz)
Green Lynx
Oxyopldae
F
24-S-82
2223
I.
Soybean
Peucetla
vlrldans
(Hentz)
Green Lynx
Oxyopldae
* +
F
09-S-81
2303
I.
Soybean
Peucetla
vlrldans
(Hentz)
Green Lynx
Oxyopldae
*. +
M
03-S-82
2323
E,
Beggarweed
Peucetla
vlrldans
(Hentz)
Green Lynx
Oxyopldae
A, +
M
03-S-82
2340
I.
Slcklepod
Peucetla
vlrldans
(Hentz)
Green Lynx
Oxyopldae
A. +
M
25-S-82
0023
I.
Hairy Indigo
Peucetia
vlrldans
(Hentz)
Green Lynx
Oxyopldae
* P
M
04-S-82
0052
I.
Soybean
Peucetia
vlrldans
(Hentz)
Green Lynx
Oxyopldae
A, +
M
04-S-82
0111
I.
Slcklepod
Peucetla
vlrldans
(Hentz)
Green Lynx
Oxyopldae
A, F
M
04-S-82
0136
I.
Soybean
Peucetla
vlrldans
(Hentz)
Green Lynx
Oxyopldae
*, +
M
21-A-81
0545-0701
I.
Soybean
Peucetia
vlrldans
(Hentz)
Green Lynx
Oxyopldae
I. +
+
25-A-81
0545-0703
E,
Grass
Peucetla
vlrldans
(Hentz)
Green Lynx
Oxyopldae
*. +
M
15-S-8I
0545-0714
I.
Soybean
Peucetia
vlrldans
(Hentz)
Green Lynx
Oxyopldae
*, +
M
03-S-8I
2230
E.
Bahlagrass
Mlsumenops celer
(Hentz)
Crab
Thomlsldae
A, +
M


116 -
140 plants were sampled on each sample date between 0430 and 0630*.
Sample unit size varied from one to two plants (see Appendix F for egg
density data). Differences in sampling between 1981 and 1982 reflected
knowledge gained on the temporal occurrence of oviposition (see Chapter
III) and on temperature-dependent egg development. In all years, plants
were removed individually from the walk-in chamber and all plant
surfaces were searched for eggs. Typically, one to three days were
required to search all the plants. Eggs were examined with a 70X
dissecting microscope and identified to species (see Appendix E for an
identification key of Lepidoptera eggs on soybeans). All VBC eggs were
aged by coloration. On the first day of each sample date, all light-
green VBC eggs were held and checked for viability. Eggs that speckled
were considered viable (see below). Field temperature was monitored
continuously at 0.2 m above ground with a hygrothermograph (Weather
Measure Corp., Model H311).
Results and Discussion
Egg Development and Coloration
Velvetbean caterpillar eggs demonstrated a series of color changes
during development that were temperature-dependent. "Freshly-laid" eggs
typically were light green but also demonstrated off-white, transparent
and faintly-green colors [Fig. 5.1(A)]. "Middle-aged" eggs were colored
like freshly-laid eggs but were speckled brownish red; speckles also
were brown, reddish brown and rarely white in color [Fig. 5.1(B)], Eggs
about to hatch were light brown, or "brownish", with a visible larval
head-capsule [Fig. 5.1(C)],
*Ovipositional rate during these times is known to be extremely low (see
Chapter III).


- 47
the right but was never observed. Following the swing manuver, both
adults essentially were in the same horizontal plane, heads were pointed
in opposite directions, and their abdominal ends were connected caudally
(see Fig. 3.1). Typically, in opposing position, the female faced
skyward and the male faced earthward. Males were observed with their
feet on plant substrate or dangling in air.
Couples were immobile during the opposing position. If touched,
couples remained immobile, walked less than 5 cm, or fell to the ground
or a plant structure. In falling, adults slowly fluttered their wings.
Wing movement stopped upon landing and adults became immobile. Upon
separation, males flew away within ca. 5 min but females remained at the
copulation site for a longer but undetermined length of time. Greene et
al. (1973) noted a similar scenario of immobility during copulation and
of separation activities. Typically, coupled adults were not disturbed
by other adults but on two separate occasions an adult male flew into
and bumped a mating pair. After several bumps the males flew away.
Perhaps these females were still emitting pheromone.
In 1981, 7 pairs of adults were timed for length of opposing
position. All pairs were found on soybean within one hour after sunset,
and all pairs had coupled prior to their location (except for one pair).
These adults may have been coupled for an hour prior to their location,
but mating was uncommon in the first .5 h after sunset and was never
observed during photophase (see below). Opposing position was
maintained for 2 h 10 min 32 min (x SD), and this time closely
agrees with that reported by Greene et al. (1973).
Adults in opposing position were observed 157 times, with 135 on
soybean, 11 on beggarweed [Desmodium tortuosum (Sw.) DC.], 9 on hairy
indigo (Indigofera hirsuta L.), and 2 on bahiagrass (Paspalum notatum


PAGE
VII SUMMARY AND CONCLUSIONS 147
APPENDICES
A AGRONOMIC PRACTICES AND SOYBEAN PHENOLOGICAL-STAGES 155
B IDENTIFICATION OF ADULT Anticarsia gemmatalis Hubner
and Mocis latipes Guenee 161
C BEHAVIORAL OBSERVATIONS: QUANTITATIVE TECHNIQUE AND DATA.... 168
D ADULT DENSITY AND PHYSICAL VARIABLE DATA, AND
MATHEMATICAL DESCRIPTIONS OF PHYSICAL VARIABLES 203
E PICTORIAL KEY OF SOME LEPIDOPTERA EGGS FOUND ON SOYBEAN 237
F EGG DENSITY DATA 273
G SAS PROGRAMS AND DATA FILES FOR MODEL OF ADULT AND
EGG POPULATIONS 276
LITERATURE CITED 285
BIOGRAPHICAL SKETCH 297
xii -


Table 2.4.
Reported host plants of larval velvetbean caterpillar (modified from Moscardi 1979, Herzog
and Todd 1980).
Family Scientific Name
Common Name
Reference
Leguminosae Aeschynomenes sp.
Agati grandiflora (L.) Desv.
Arachis hypogaea L.
Cajanus cajans (L.) Millsp.
Cajanus indicus Spreng
Canavalia gladiata (Sav.)
Canavalia martima Aub.
Canavalia rosea Sw.
Canavalia sp.
Joint Vetch
Gallito Trees
Peanut
Pigeon Pea
Pigeon Pea
Sword Bean
de Cond.
Horse Bean
Canavalia
Cassia fasciculata Michx.
Cassia obtusifolia L.
Desmodlum floridanum Chapm.
Partridge Pea
Coffeeweed
Beggar Lice
DPIb
Wolcott (1936)
Anonymous (1928)
McCord (1974)
DPIb
Ellisor (1942)
Buschman et al. (1977)
Tietz (1972)
Watson (1916a), Ellisor (1942),
Tietz (1972)
Herzog (unpublished)
Buschman et al. (1977)
Buschman et al. (1977)


Table D.2 (continued)
Calendar
Date
Julian
Date
Number of
Females
Number of
Males
Number of Total
Adults
Total
Smoothed
Weighted
Total
Smoothed
Weighted
Total
Smoothed
Weighted
Sept. 17
260
32
26.75
0.20
95
80.63
0. 18
127
106.81
0.19
18
261
26
26.00
0.00
66
66.00
0.00
92
92.00
0.00
19
262
6
26.25
-0.77
13
53.00
-0.75
19
82.25
-0.77
20
263
1
26.75
-0.96
9
41.13
-0.78
10
75.00
-0.87
21
264
27
27.00
0.00
58
35.63
0.63
85
72.25
0.18
22
265
66
29.00
1.28
93
35.25
1.64
159
75.69
1.10
23
266
27
33.00
-0.18
37
37.94
-0.02
64
82.56
-0.22
24
267
35
35.00
0.00
39
43.31
-0.10
74
86.00
-0.14
25
268
46
35.00
0.31
46
46.00
0.00
92
85.50
0.08
26
269
48
36.00
0.33
114
46.63
1.45
162
84.50
0.92
27
270
33
38.00
-0.13
50
47.88
0.04
83
83.00
0.00
28
271
32
39.00
-0.18
47
47.00
0.00
79
78.69
0.00
29
272
42
39.00
0.08
29
41.88
-0.31
71
72.81
-0.02
30
273
39
39.00
0.00
31
35.13
-0.12
70
70.00
0.00
Oct. 1
274
29
38.75
-0.25
36
31.50
0.14
65
69.56
-0.07
2
275
41
38.25
0.07
42
32.50
0.29
83
69.19
0.20
3
276
38
37.19
0.02
31
35.50
-0.13
69
69.00
0.00
4
277
35
35.25
-0.01
26
37.50
-0.31
61
69.50
-0.12
211


- 56 -
.10 to 1.25 m, based on visual estimates. When ovipositing on a
leaflet, a female (1) landed on the leaflet, (2) moved her abdominal tip
back and forth across the leaflet surface and sometimes walked at the
same time, (3) positioned her abdominal tip against a leaflet vein, (4)
arched her abdomen with the abdominal tip directed downward, (5) pressed
her abdominal tip against the leaflet surface and the vein, exposing the
conjunctiva anterior of the ovipositor, and (6) laid an egg.
Oviposition on plant structures other than leaflets followed the same
procedure, with the obvious exception that eggs were not laid on leaflet
veins. Time required to lay an egg varied from ca. 2 to 30 sec, and
eggs were glued to the surface and trichomes of the plant structure.
Twenty-four hours later, eggs were impossible to remove without
crushing. Contrary to present observations, Greene et al. (1973)
indicated that eggs were nearly impossible to remove immediately after
oviposition and that oviposition occurred in 2-60 sec, twice as much
time as observed here.
All eggs were laid singly on leaflets, pulvini, or petioles, except
for 19 September 1981 (ca. 2000) when one female laid seven eggs on a
leaflet and another female attempted to lay three eggs on a leaflet.
Low ambient temperature (17.7C) affected the behavior of these two
females. While ovipositing, both females continuously vibrated their
wings, a previously unobserved ovipositional activity. Presumably, wing
vibration allowed for ovipositonal activity at this temperature; wing
vibration without flight in Lepidoptera allows for activities at
suboptimal temperatures (Chapman 1971). Both females vibrated their
wings for ca. 1 min before flying to another leaflet. Their flight
speed was very slow and wing beat was flap-like.


Table D.7. Values of physical variables regressed against blacklight trap catch data (1981). Mathematical
descriptions of physical variables are listed in Table D.6.
Vapor
Press. Wind
Calendar
Date
Julian
Date
Flight
Temp. (C)
Deficit
(mm Hg)
Moonlight
Intensity
Speed
(m/s)
Wind
Direction
Rainfall
Barometric
Press. (MB)
Aug. 4
216
9.11
.407
.0000
.869
161.3
.0803
1020.93
5
217
10.42
.944
.0198
.081
148.2
.0000
1019.95
6
218
11.89
1.576
.0347
.092
124.0
.0000
1015.94
7
219
13.00
1.992
.0482
.254
155.8
.0000
1013.23
8
220
13.20
1.965
.0891
.224
138.1
.0000
1015.98
9
221
13.50
2.705
.1028
.386
166.7
.0000
1020.29
10
222
11.84
2.067
.1901
.203
154.6
.0000
1020.78
11
223
10.17
.595
.0502
.297
128.3
.0031
1018.28
12
224
10.37
1.477
.1967
.253
149.2
.0000
1017.84
13 .
225
11.08
1.066
.2583
.571
129.2
.0000
1018.89
14
226
10.93
2.272
.8455
.505
120.1
.0000
1017.45
15
227
11.33
2.837
.9200
.647
151.8
.0000
1014.16
16
228
12.24
3.700
.7953
.773
135.6
.0000
1010.87
17
229
12.65
2.496
.4797
1.868
123.5
.0000
1010.36
18
230
11.89
2.539
.0236
2.137
93.0
.0000
1009.13
19
231
12.54
2.388
.0388
.494
156.1
.0000
1011.93
227


MEAN NUMBER OF SPERMATOPHORES
4 -
3 -
2 -
I -
01 1 __i
200
I
VO
I
-1
210
_i
220
i i i i i i i i 1 1 1 1 1
230 240 250 260 270 280 290
JULIAN DATE (1981)
Figure 4.5. The mean number of spermatophores per adult velvetbean caterpillar female per week.
Females were caught in a blacklight trap during 1981 at the Green Acres Research Farm,
Alachua County, FL.


Figure 3.7. Adult velvetbean caterpillar feeding at the surface of a dead soybean leaflet. Photograph
was made in a soybean field in Melrose, FL, Alachua County, 7 October 1983.


Abstract of Dissertation Presented to the Graduate School
of the University of Florida in Partial Fulfillment of the
Requirements for the Degree of Doctor of Philosophy
A MODEL OF ADULT AND EGG POPULATIONS
OF Anticarsia gemmatalis Hubner
(LEPIDOPTERA: NOCTUIDAE) IN SOYBEAN
By
BEN GREGORY, JR.
May, 1986
Chairman: C. S. Barfield
Major Department: Department of Entomology and Nematology
A model of adult and egg populations of the velvetbean caterpillar
(A. gemmatalis) was constructed and validated. The model mimicked
velvetbean caterpillar (VBC) egg densities in a soybean field within 95%
confidence intervals of estimated means. Model construction was based
on data from nine separate experiments (1980-84) that allowed for an
understanding or quantification of the following: adult moth
identification, adult behavior in the field, relative and absolute
estimates of adult density, female reproductive states, egg
identification, egg developmental rates, absolute estimates of egg
density, and the impact of various environmental variables on adult and
egg dynamics.
Adult density estimates were obtained with a blacklight trap and an
unique adult trap-cage. These density estimates were calibrated with a
linear regression equation that was used in the model structure to
- xix


151
Velvetbean caterpillar eggs are similar in morphological appearance
to a number of other lepidopteran eggs found on soybean. Differences
and similarities among these eggs are discussed in Appendix E and should
be useful information to researchers encountering these eggs. Accurate
identification of VBC eggs is necessary to sample and measure egg
density.
Velvetbean caterpillar eggs are polychromatic and change color
during development. The appearance of these different colors is
temperature-dependent and was used to age eggs. Determination of the
mean number of eggs oviposited per 0.91 m-row in soybean per night was
possible only after the acquisition of knowledge on the temporal
occurrence of oviposition and the establishment of a sampling time based
on the temperature-dependent color changes of eggs. This approach
avoided the problem of indiscriminately partitioning VBC eggs into
various age categories as model construction and validation required
data on the number of eggs oviposited in the field on a particular
night. Egg density data collected in 1982 were necessary for model
construction and determination of parametric values, while egg density
data from 1981 served for model validation.
Egg densities predicted by the model were more accurate with a
variable ovipositional rate as opposed to a constant rate. The variable
ovipositional rate was linked to changes in soybean phenology and
allowed for interaction between VBC and soybean. In model validation,
65% of the model's predicted values fell within the 95% confidence
intervals of the 1981 field estimates. Differences between predicted
and estimated values were attributed to unpredictable fluctuations in
BLT catch and to variation in ovipositional rate between years. The


Table C.8 (continued)
Da tea
(D-M-Y)
.. *>
Hour
MaleC
Agg
Male1*
OAgg
Male'
All
Female^
Adult8
MFA*1
Agg
MFA1
OAgg
Time
04-S-82
9
0
0
0
0
0
0
0
19
07-S-82
9
0
0
0
0
0
0
0
1
ll-S-82
9
0
0
0
0
0
0
0
11
I4-S-82
9
0
0
0
0
0
0
0
7
18-S-82
9
0
0
0
0
0
0
0
2
25-S-82
9
0
2
2
8
0
10
10
52
04-A-81
10
0
0
0
0
0
0
0
30
07-A-81
10
0
0
0
0
0
0
0
25
11A81
10
0
0
0
0
0
0
0
20
14-A-81
10
0
0
0
0
0
0
0
15
16-A-81
10
0
1
1
5
1
7
7
45
18-A-81
10
0
0
0
0
3
3
3
23
21-A-81
10
0
2
2
1
0
3
3
20
25-A-81
10
0
0
0
2
0
2
2
16
28-A-81
10
0
0
0
0
0
0
0
13
Ol-S-81
10
0
0
0
0
0
1
1
8
04-S-81
10
0
0
0
0
0
0
0
4
13-S-8I
10
0
0
0
0
0
0
0
60
28-A-82
10
0
0
0
0
0
0
0
53
Weight** Weight* Weight10 Weight11 Weight0 Weight* Weight*
1 2 3 A 5 6 7
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.038A62
0.000000
0.000000
0.000000
0.000000
0.022222
0.000000
0.100000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.038A62
0.000000
0.000000
0.000000
0.000000
0.022222
0.000000
0.100000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.1538A6
0.000000
0.000000
0.000000
0.000000
0.111111
0.000000
0.050000
0.125000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.022222
0.130A35
0.000000
0.000000
0.000000
0.125000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0. 192308
0.000000
0.000000
0.000000
0.000000
0.155556
0.130A35
0.150000
0.125000
0.000000
0.125000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.192308
0.000000
0.000000
0.000000
0.000000
0.155556
0.130A35
0.150000
0.125000
0.000000
0.125000
0.000000
0.000000
0.000000


Table D.3 (continued)
Calendar
Date
Julian
Date
Number of
Females
Number of
Males
Number of Total
Adults
Total
Smoothed
Weighted
Total
Smoothed
Weighted
Total
Smoothed
Weighted
July 25
206
0
1.50
-1.00
3
2.29
0.31
3
3.21
-0.06
26
207
2
2.44
-0.18
3
3.28
-0.08
5
5.38
-0.07
27
208
4
3.76
0.06
4
4.14
-0.03
8
8.00
0.00
28
209
6
4.33
0.39
5
4.81
0.04
11
9.42
0.17
29
210
5
3.85
0.30
7
5.50
0.27
12
9.52
0.26
30
211
2
2.90
-0.31
2
6.08
-0.67
4
9.09
-0.56
31
212
0
2.42
-1.00
9
6.36
0.42
9
8.71
0.03
Aug. 1
213
2
2.56
-0.22
5
6.50
-0.23
7
8.66
-0.19
2
214
6
2.83
1.12
8
6.66
0.20
14
8.78
0.59
3
215
4
3.22
0.24
5
6.99
-0.28
9
9.22
-0.02
4
216
1
3.36
-0.70
9
7.20
0.25
10
9.55
0.05
5
217
10
3.02
2.32
33
7.43
3.44
43
9.78
3.40
6
218
2
3.41
-0.41
5
8.60
-0.42
7
11.86
-0.41
7
219
3
5.70
-0.47
5
13.62
-0.63
8
19.67
-0.59
8
220
10
9.73
0.03
18
25.89
-0.30
28
36.29
-0.23
9
221
16
13.28
0.20
57
38.74
0.47
73
52.67
0.39
10
222
21
14.47
0.45
57
43.41
0.31
78
58.42
0.34
11
223
15
13.93
0.08
39
37.82
0.03
54
52.28
0.03
215


Table C.8 (continued)
^Weight 2
"'Weight 3
nWeight U
Weight 5
^Weight 6
^Weight 7
(Male OAgg/Minute)
(Male All/Minute)
(Female/Minute)
(Adult/Minute)
(MFA Agg/Minute)
(MFA OAgg/Mlnute)
I
I
194


142 -
influence the behavior of ovipositing insects (see Hinton 1981). "Among
species that do not practice any form of parental care following egg
deposition, proper egg placement is particularly crucial. In the final
stages of site selection considerable time and energy may be spent on
fine discriminations regarding a wide variety of factors related to food
availability, food suitability, and predator pressures." (Matthews and
Matthews 1978, p. 404). For example, adult females of the noctuid moth
Autographa precationis (Guenee) prefer to oviposit on soybeans over
dandelions apparently because soybean leaf shape is a more effective
oviposition stimulus; however, larvae demonstrate a marked feeding
preference for dandelions (Kogan 1975). In another example, Heliconius
butterflies in the Neotropics spend considerable time inspecting host
plants prior to oviposition, apparently searching for Heliconius eggs or
larvae because larvae are cannibilistic (Gilbert 1975). Finally,
pipevine swallowtail butterflies, Battus philenor (Linnaeus), select
host plants largely in response to leaf shape cues (Papaj and Rausher
1983).
Simulation of 1981 Egg Population with a Variable Ovipositional Rate
Quantitative validation of model behavior was attempted by
comparing simulated egg density with 1981 field estimates.
Ovipositional rates and other parameters were determined with
experimental data and model simulations from 1982. Data specific to
1981 (i.e., soybean phenological stage and field size) were incorporated
into the 1981 model structure. Simulations depicted in Fig. 6.4, show
that 15 of 23 (65%) predicted egg density values fell within 95%
confidence intervals of field estimates. The six disagreements between
predicted and estimated values from dates 197 to 218 indicate that


- 82
dynamics, Wilkerson et al. (1983) found that changes in the density and
influx timing of adults into soybean resulted in notable differences in
soybean yield and grower profit (from -$289.63 to $169.21/ha)(see Table
1.1). Clearly, knowledge of when and why adults immigrate into soybean
could provide a better understanding of VBC dynamics and lead to more
enlightened management.
The present study was initiated to quantify and model adult and egg
populations of VBC within soybean. Model construction depended on
estimates of adult and egg densities. Data on adult density were
essential for model initialization and data on egg density (see Chapter
V) were required to assess the impact of adult reproduction in the field
(i.e., the mere presence of adults does not connote the presence of eggs
and resultant larval defoliators). In the present study, adult VBC
density was monitored in soybean, the reproductive status of adult
females was determined, and select environmental variables were
monitored.
Materials and Methods
Adult Sampling
Adult VBC density was monitored (1980-82) in a 1 ha soybean field
(cv. Bragg), at the University of Florida's Green Acres Research Farm
(ca. 22.5 km west of Gainesville, FL, Alachua County). Specific
agronomic practices and soybean phenological stages are listed in
Appendix A. Adult VBC density was measured with two devices. The first
device, a blacklight trap (BLT), was used in all three years, was placed
in the field, and was situated 21.2 m diagonally from a field corner and
15 m from the closest field edges. The blacklight trap in 1980 did not
conform to the BLT standards recommended by the Entomological Society of
America, but the trap in 1981 and 1982 did meet the society's


PAGE
Figure 4.4. Total number of velvetbean caterpillar unmated
adult females per fat body content category
per night 94
Figure 4.5. The mean number of spermatophores per adult
velvetbean caterpillar female per week 97
Figure 4.6. Mean number ( 90% confidence interval) of
velvetbean caterpillar moths captured per
sample (21.16 m2) with the adult trap-cage 98
Figure 4.7. Vapor pressure deficit (VPD) in a 1 ha
soybean field in 1981 at the Green Acres
Research Farm, Alachua County, FL 100
Figure 4.8. Vapor pressure deficit (VPD) in a 1 ha
soybean field in 1982 at the Green Acres
Research Farm, Alachua County, FL 101
Figure 4.9. Sex ratio of velvetbean caterpillar adults
caught in blacklight traps (BLT) and an adult
trap-cage (ATC) in a 1 ha soybean field at the
Green Acres Research Farm, Alachua County, FL 103
Figure 5.1. Eggs of the velvetbean caterpillar 117
Figure 5.2. Developmental rate of speckling in VBC eggs
at six different temperatures 121
Figure 5.3. Mean densities per .91 m-row ( 95% confidence
interval) of freshly-laid VBC eggs on soybean
at the Green Acres Research Farm, Alachua
County, FL 125
Figure 6.1. Flow diagram of a model of VBC adult and egg
populations in a soybean field 131
Figure 6.2. Mean velvetbean caterpillar egg density per
.91 m-row of soybean during 1982 in a 1 ha
field at the Green Acres Research Farm, Alachua
County, FL. Ovipositional rate was a constant
during the simulation 138
Figure 6.3. Mean velvetbean caterpillar egg density per
.91 m-row of soybean during 1982 in a 1 ha
field at the Green Acres Research Farm, Alachua
County, FL. Ovipostional rate was variable
during the simulation 140
- xvii -


Si b
Table D.2. Total, smoothed-total and weighted number of females, males, and adults (males and females)
caught in a blacklight trap in 1981 at the Green Acres Research Farm, Alachua County, FL. Trap
did not operate on date 174.
Calendar
Date
Julian
Date
Number of
Females
Number of
Males
Number of Total
Adults
Total
Smoothed
Weighted
Total
Smoothed
Weighted
Total
Smoothed
Weighted
June 21
172
0
0.00
0.00
0
0.00
0.00
0
0.00
0.00
22
173
0
0.00
0.00
0
0.00
0.00
0
0.00
0.00
23
174
-
-
-
-
-
-
-
-
-
24
175
0
0.00
0.00
0
0.00
0.00
0
0.00
0.00
25
176
0
0.00
0.00
1
0.00
0.00
1
0.00
0.00
26
177
0
0.00
0.00
0
0.00
0.00
0
0.00
0.00
27
178
0
0.00
0.00
0
0.00
0.00
0
0.00
0.00
28
179
0
0.00
0.00
0
0.00
0.00
0
0.00
0.00
29
180
0
0.00
0.00
0
0.00
0.00
0
0.00
0.00
30
181
0
0.00
0.00
0
0.00
0.00
0
0.00
0.00
July 1
182
0
0.00
0.00
0
0.00
0.00
0
0.00
0.00
2
183
0
0.00
0.00
0
0.00
0.00
0
0.00
0.00
3
184
0
0.00
0.00
0
0.00
0.00
0
0.00
0.00
4
185
0
0.00
0.00
0
0.00
0.00
0
0.00
0.00
5
186
0
0.00
0.00
0
0.00
0.00
0
0.00
0.00
6
187
0
0.00
0.00
0
0.00
0.00
0
0.00
0.00
206


- 38 -
bahiagrass, Paspalum notatum Flugge, throughout scotophase but most
abundantly at sunset. The food source on the bahiagrass seed heads was
not determined. Moths were observed to feed on dew droplets on soybean
and on water in a cup. The chemical content of the dew and water was
not determined.
Various honey solutions have been used for adult food in numerous
laboratory studies (see Leppla 1976, Leppla et al. 1979, Johnson et al.
1981, Moscardi et al. 1981b, Moscardi et al. 1981c, Oliveira 1981, Wales
1983). The effect of variation in adult diet on oviposition and
longevity was explored by Wales (1983). "Moths fed 5% or 10% honey
solution had mean longevities of 19.6 and 16.4 days and mean fecundities
of 846.1 and 866.2 eggs/female, respectively. Water-fed females lived
9.3 days and produced 212.7 eggs, and unfed females lived 5.7 days and
produced 41.6 eggs/female" (Wales 1983, p. ix).
Predators
Little is known about predators of adult VBC. Watson (1915, 1916c)
reported dragonflies as predators but listed no common or scientific
names. Neal (1974) reported two predatory species, the green jacket
dragonfly, Erythemis simplicicollis (Say), and the striped earwig,
Labidura riparia (Pallas).
Research Goals
The present study on the behavioral ecology of adult VBC was
initiated as part of a project to explore the movement of adult VBC into
a soybean field (review pp. 27-28). To examine this movement, a
mathematical relationship had to be established between adult and egg
densities in a soybean field (see Chapter VI). To obtain estimates of
adult and egg densities (see Chapters IV and V), and to establish a
relationship between these estimates, a number of questions about adult


- 58 -
Table 3.3. Mean total oviposition by adult females of the
velvetbean caterpillar reared from eggs at constant
temperatures, 14L:10D photoperiod, and RH > 80%
(modified from Moscardi et al. 1981c).
Temperature Number of
(C) Mated Females
Mean
Total-Eggs/Female ( SE)a
21.1
19
482.8
+
21.3C
23.9
29
732.3
+
22.9B
26.7
25
842.2
+
26.1A
29.4
15
713.5
+
28.IB
32.2
19
310.0

14.7D
^eans followed by the same letter are not significantly
different according to Duncan's multiple range test (a = .05).


Table 3.7. Number of male and female adults of the velvetbean caterpillar feeding in
a soybean field at Green Acres Research Farm, Alachua County, FL, from
1980-82. Description of food site and host provided.
No. of3
Males
Feeding
No. ofb
Females
Feeding
Food SiteC
Food Host
Common Name
Scientific Name
Family
i
i
Seed
Slender Amaranth
Amaranthus vlrldis L.
Amaranthaceae
50
84
Raceme
Bahlagrass
Paspalum notatum Flugge
Gramineae
12
11
Leaflet
Soybean
Glycine max (L.) Merr.
Leguminosae
3
2
Leaflet Dead
Soybean
Glycine max (L.) Merr.
Leguminosae
0
1
Stem, Dead
Unknown Plant**


3
2
Leaflet, Dead
Beggarweed
Desmodlum tortuosum (Sw.) DC.
Leguminosae
2
2
Roots, Stems, Dead
Beggarweed
Desmodlura tortuosum (Sw.) DC.
Leguminosae
1
0
Seed
Beggarweed
Desmodlum tortuosum (Sw.) DC.
Leguminosae
0
1
Seed
Florida Pusley
Rlchardla scabra L.
Rublaceae
3
2
Leaflet
Slcklepod
Cassia obtuslfolla L.
Leguminosae
2
2
Flower, Outside
Hairy Indigo
Indlgofera hirsuta L.
Leguminosae
1
1
Flower, Outside, Dead
Hairy Indigo
Indlgofera hirsuta L.
Leguminosae
9
18
Flower
Hairy Indigo
Indlgofera hirsuta L.
Leguminosae
2
0
Leaflet
Hairy Indigo
Indlgofera hirsuta L.
Leguminosae
0
2
Leaflet, Dead
Hairy Indigo
Indlgofera hirsuta L.
Leguminosae
0
2
Flower
Common Beggar Tick
Bldens alba (L.) DC.
Composltae
aTotal males 89.
^Total females 131.
Adults fed at the surfaces of plant structures or in flowers.
^Dicotyledonous plant.


Si b
Table D.3. Total, smoothed-total and weighted number of females, males, and adults (males and females)
caught in a blacklight trap in 1982 at the Green Acres Research Farm, Alachua County, FL. Trap
did not operate on date 235.
Calendar
Date
Julian
Date
Number of
Females
Number of
Males
Number of Total
Adults
Total
Smoothed
Weighted
Total
Smoothed
Weighted
Total
Smoothed
Weighted
June 21
172
0
0.00
0.00
0
0.00
0.00
0
0.00
0.00
22
173
0
0.00
0.00
0
0.00
0.00
0
0.00
0.00
23
174
0
0.00
0.00
0
0.00
0.00
0
0.00
0.00
24
175
0
0.00
0.00
0
0.00
0.00
0
0.00
0.00
25
176
0
0.00
0.00
0
0.00
0.00
0
0.00
0.00
26
177
0
0.00
0.00
0
0.00
0.00
0
0.00
0.00
27
178
0
0.00
0.00
0
0.00
0.00
0
0.00
0.00
28
179
0
0.00
0.00
0
0.00
0.00
0
0.00
0.00
29
180
0
0.00
0.00
0
0.00
0.00
0
0.00
0.00
30
181
0
0.00
0.00
0
0.00
0.00
0
0.00
0.00
July 1
182
0
0.00
0.00
0
0.00
0.00
0
0.00
0.00
2
183
0
0.00
0.00
0
0.00
0.00
0
0.00
0.00
3
184
0
0.00
0.00
0
0.00
0.00
0
0.00
0.00
4
185
0
0.00
0.00
0
0.00
0.00
0
0.00
0.00
5
186
0
0.00
0.00
0
0.00
0.00
0
0.00
0.00
6
187
0
0.00
0.00
0
0.00
0.00
0
0.00
0.00
213


92 -
4 and 1 contained smaller numbers (207 and 162, respectively); all mated
females (1126) contained mature and/or maturing eggs. Seventy-one
percent of all females belonged to categories 2 and 3. The total number
of females per category per night mirror similar results (see Fig. 4.3).
Based on BLT catch and dissections, most of the females in the field on
any given night were females with high reproductive potential.
Only mated females (categories 2 and 3) were caught initially.
Apparently, they moved into the field seeking oviposition sites*.
Unmated females were caught in increasing numbers after date 241, and
may have been individuals that completed their immature development in
the field. Adult generations in another noctuid pest of soybean, the
green cloverworm [Plathypena scabra (Fabricius)], have been indicated by
cyclic patterns of unmated females (see Buntin and Pedigo 1983), but
these cyclic patterns were not apparent in 1981 with VBC females (see
Fig. 4.3).
Unmated females were placed into three categories (see Materials
and Methods). Full and medium categories had essentially the same total
number of individuals (78 and 79, respectively), while the empty
category had only five individuals. The total number of unmated females
per category per night mirror similar results (see Fig. 4.4). Based on
BLT catch and these dissections, most unmated females in the field
should demonstrate a high reproductive output after mating. Also, most
females mated before their fat body had been depleted.
Spermatophores were removed from all mated females (1126) caught in
the BLT during 1981 with the following results: 1587 spermatophores
were counted, females contained one to four spermatophores, and the mean
*Eggs were first found in the field on date 205 (see Chapter V).


- 83 -
recommendations (see Harding et al. 1966). New 15 w bulbs (General
Electric F15T8-BL) were installed each field season, and the funnel top
of each trap was positioned 1.5 m above the ground. Isopropanol (99%)
was used as the killing agent and was changed daily (1.89 L/day). Adult
VBC were segregated daily from total trap catch, counted, sexed and
stored in 5% formalin.
The second adult monitoring device, an adult trap-cage, was used
during the day in 1982 (Fig. 4.1). Development of this trap resulted
from the observation that adults reside in the soybean field during the
day (see Chapter III). Outside dimensions of the cage were 4.6 x 4.6 x
2.1 m, and the frame was constructed of 1.25 inch polyvinylchloride pipe
(PVC, PR160). The frame was covered with Lumite Saran Screen (Chicopee,
Style //51821000) that extended 0.3 m below the cage on all sides (i.e.,
extension flaps). Four people carried the cage (one at each corner) via
0.9 m handle and walked one row distant from the sampled rows. The cage
covered six rows of soybean and was carried above the crop canopy to
avoid the flushing of VBC adults. At each sample site, bearers dropped
the cage rapidly and quickly buried the extension flaps with soil. The
cage was entered via a full length zipper on one side.
Each week, six simple random samples were taken with the adult
trap-cage. One hour was spent inside the cage at each sample site. To
assist in the exposure and capture of adults inside the cage, all weeds
were removed and soybean foliage was shaken vigorously. Adults were
caught with an aerial net and placed initially in a vial of 99%
isopropanol. Most adults were caught within 20 min and none were caught
after 40 min. Adults were counted, sexed, and stored in 5% formalin.


- 265 -
Figure E.6 (continued)


104
Table 4.4. Mean seasonal sex ratios of adult velvetbean
caterpillar caught in blacklight traps and an adult
trap-cage in a 1 ha soybean field at the Green Acres
Research Farm, Alachua County, FL.
Year
Trap3
Number
of Samples
Mean Sex Ratio*5
(SE)
1980
BLT
59
.54
.03 B
1981
BLT
89
.69
.02 C
1982
BLT
103
.51
.02 B
1982
ATC
49
.35
.05 A
aBLT = blacklight trap.
ATC = adult trap-cage.
^Means followed by different letters are significantly different
according to Duncan's Multiple Range Test (a = .05).


- 258 -
Figure E.4 (continued)


196
203
210
217
224
231
238
245
252
259
266
273
280
287
224 -
Mean number (SE) of females, males, and total adults
per 21.16 m2 caught in an adult trap-cage during 1982
at the Green Acres Research Farm, Alachua County, FL
(n = 6, N = 416.59).
Mean Number (SE)
Female Male Adult
.00
+
.00
.00
+
.00
.00
.00
.00
+
.00
.00
+
.00
.00
.00
.00
+
.00
.00
+
.00
.00
.00
1.00
+
.37
.00

.00
1.00
.37
.83
+
.31
.00

.00
.83
.31
1.00
+
.45
.83
+
.48
1.83
.60
4.33
+
.67
3.17
+
.75
7.50
.81
6.17
+
.87
6.33
+
1.20
12.50
1.96
5.50
+
1.57
5.17
+
.65
10.67
2.14
1.67
+
.76
1.17
+
.48
2.83
.70
1.83
+
1.11
1.17
+
.48
3.00
1.39
.50
+
.34
.83
+
.83
1.33
.80
.83
+
.65
.17
+
.17
1.00
.82
1.00
+
.52
.17
+
.17
1.17
.60


Table D.4 (continued)
Total Number
Julian Sample
Date Number Females Males Adults
280 1 0
2 0
3 0
4 0
5 4
6 1
0
0
0
0
1
0
0
0
0
0
5
1
Total Number
Julian Sample
Date Number Females Males Adults
287 1 0
2 0
3 0
4 2
5 1
6 3
0
0
0
1
0
0
0
0
0
3
1
3
i
i
223


- 289 -
Henderson, J. B. and E. J. Kamprath. 1970. Nutrient and dry matter
accumulation in soybeans. N.C. Agrie. Exp. Sta. Tech. Bull. No.
197: 1-27.
Herzog, D. C., and J. W. Todd. 1980. Sampling velvetbean
caterpillar on soybean, pp. 107-140. In M. Kogan and D. C. Herzog,
eds. Sampling methods in soybean entomology. Springer-Verlag, New
York, NY.
Hinds, W. E. 1930. The occurrence of Anticarsia gemmatalis as a
soybean pest in Louisiana in 1929. J. Econ. Entomol. 23(4):
711-714 and 3 plates.
Hinds, W. E. and B. A. Osterberger. 1931. The soybean caterpillar
in Louisiana. J. Econ. Entomol. 24(6): 1168-1173.
Hinton, H. E. 1981. Biology of insect eggs. Pergamon Press, New York,
NY. Vol. 1-3.
Hogg, D. B. and A. P. Gutierrez. 1980. A model of the flight phenology
of the beet armyworm (Lepidoptera: Noctuidae) in central
California. Hilgardia. 48(4): 1-36.
Housley, T. L., L. E. Schrader, M. Miller, and T. L. Setter. 1979.
Partitioning of C14-photosynthate, and long distance translocation
of amino acids in preflowering and flowering, nodulated and
nonnodulated soybeans. Plant Physiol. 64: 94-98.
Hubner, J. 1816. Verzeichniss bekannter Schmetterlinge [Catalog of
the known Lepidoptera]. N.P. Augsburg, Germany.
Hymowitz, T. 1970. On the domestication of the soybean. Econ. Bot.
24(4): 408-421.
Jaycox, E. R. 1970. Ecological relationships between honey bees and
soybeans. II. The plant factors. Am. Bee J. 110(9): 343-345.
Johnson, D. W., C. S. Barfield, and G. E. Allen. 1983. Temperature-
dependent developmental model for the velvetbean caterpillar
(Lepidoptera: Noctuidae). Environ. Entomol. 12(6): 1657-1663.
Johnson, D. W., E. R. Mitchell, J. H. Tumlinson, and G. E. Allen.
1981. Velvetbean caterpillar: Response of males to virgin females
and pheromone in the laboratory and field. Fla. Entomol. 64(4):
528-533.
Jordon, D. C. 1982. Transfer of Rhizobium japonicum Buchanan 1980
to Bradyrhizobium gen. nov., a genus of slow-growing, root nodule
bacteria from leguminous plants. Int. J. Syst. Bacteriol. 32(1):
136-139.
Kennedy, J. S. 1972. The emergence of behavior. J. Australian
Entomol. Soc. 11: 168-176.


252 -
Figure E.3. M. latipes eggs: (A) freshly laid, (B) middle aged, (C)
middle aged, (D) parasitized, (E) parasitized, and (F)
parasitoid emerged.


FIELD VPD (mmHg) AMBIENT VPD (mm Hg)
101
JULIAN DATE (1982)
Figure 4.8. Vapor pressure deficit (VPD) in a 1 ha soybean field in
1982 at the Green Acres Research Farm, Alachua County, FL
(A) ambient VPD, and (B) field VPD.


204 -
Table D.l (continued)
Total Number
Calendar Julian
Date Date Females Males Adults
July 31
213
2
6
8
Aug. 1
214
0
3
3
2
215
4
1
5
3
216
4
2
6
4
217
9
2
11
5
218
16
29
45
6
219
11
37
48
7
220
-
-
-
8
221
30
30
60
9
222
13
12
25
10
223
20
19
39
11
224
7
44
51
12
225
-
-
-
13
226
38
54
92
14
227
26
14
40
15
228
13
24
37
16
229
34
55
89
17
230
24
21
45
18
231
21
41
62
19
232
-
-
-
20
233
36
51
87
21
234
43
96
139
22
235
24
48
72
23
236
-
-
-
24
237
49
66
115
25
238
56
73
129
26
239
30
90
120
27
240
89
177
266
28
241
55
39
94
29
242
97
129
226


Table D.2 (continued)
Number of Females
Number of Males
Number of Total
Adults
Calendar
Julian
Date
Date
Total Smoothed Weighted
Total Smoothed Weighted
Total Smoothed
Weighted
Aug. 12
224
0
2.56
-1.00
4
4.00
0.00
4
4.00
0.00
13
225
4
2.75
0.45
15
9.06
0.66
19
10.50
0.81
14
226
3
3.13
-0.04
11
13. 19
-0.17
14
16.25
-0.14
15
227
4
3.88
0.03
16
16.00
0.00
20
20.31
-0.02
16
228
1
5.00
-0.80
26
21.00
0.24
27
25.38
0.06
17
229
7
7.00
0.00
21
26.75
-0.22
28
29.31
-0.04
18
230
9
8.75
0.03
50
29.00
0.72
59
31.00
0.90
19
231
15
9.00
0.67
29
29.00
0.00
44
31.38
0.40
20
232
8
7.81
0.02
9
28.25
-0.68
17
31.13
-0.45
21
233
6
6.19
-0.03
24
26.75
-0.10
30
31.00
-0.03
22
234
5
5.50
-0.09
26
26.00
0.00
31
31.00
0.00
23
235
12
5.50
1.18
39
26.00
0.50
51
31.00
0.65
24
236
4
5.88
-0.32
23
24.69
-0.07
27
29.75
-0.09
25
237
10
6.63
0.51
42
22.06
0.90
52
27.25
0.91
26
238
3
7.00
-0.57
5
19.19
-0.74
8
25.00
-0.68
27
239
7
7.00
0.00
16
16.06
-0.00
23
23.00
0.00
28
240
14
7.25
0.93
42
14.25
1.95
56
22.00
1.55
29
241
22
7.50
1.93
59
13.75
3.29
81
22.00
2.68
209


277
Table G.l (continued)
TEGG = FTOTAL (1-VF) (1-MORT) OVI;
PEGG = TEGG/11935.696;
CARDS;
/*INCLUDE DMODEL81.DAT
********* *********** 'k-kk&£&*'k'k'k'J *** DATA FILE IS DMODEL81.DAT ***
***********************************
>
OPTIONS NOCENTER;
PROC PRINT DATA=BG1;
VAR JULIAN SOY FBLT FTOTAL VF MORT OVI TEGG LB05 EEGG UB05 PEGG
TITLE 'MODEL 1981';
PROC PLOT DATA=BG1;
PLOT LB05*JULIAN='-'
EEGG*JULIAN='E'
UB05*JULIAN='-'
PEGG*JULIAN='P'/OVERLAY;
TITLE 'MODEL 1981';
*** THIS IS FILE PMODEL81 ***;
/*


Figure 6.3. Mean velvetbean caterpillar egg density per .91 m-row of soybean during 1982 in a 1 ha
field at the Green Acres Research Farm, Alachua County, FL. Estimated density with 95%
confidence intervals determined from field collected data. Upper and lower values of the
confidence intervals are represented as hyphens. Predicted density determined with model
simulations. Ovipositional rate was variable during the simulation.
140


- 49 -
Flugge). On soybean and beggarweed, each pair was found on a leaflet.
On hairy indigo, one of the opposing pairs was observed on developing
seeds. The other eight pairs were found with each pair on several
leaflets; a hairy indigo leaflet is smaller than a VBC adult. On
bahiagrass, each opposing pair was observed on a raceme. Of the records
that were kept of adult position on leaflets, the following can be
noted: (1) for soybean, 29 pairs were on the bottom and 2 pairs on the
top, (2) for beggarweed, 4 pairs were on the bottom and 5 pairs on the
top, and (3) for hairy indigo, 1 pair was on the bottom and 1 pair on
the top. No definite preference between leaflet top and bottom was
noted for beggarweed or hairy indigo. A definite preference for the
bottom of a soybean leaflet was noted. The relevance of this preference
is unknown, but it may be a behavioral trait to avoid predation. Moths
mating on the bottom of a leaflet are more difficult to see than moths
on the top of a leaflet. As moths are docile and immobile during
mating, adults on the top of a leaflet may be seen and preyed upon more
readily by predators.
Mating occurred exclusively on legume plants, except for 2 pairs in
1980 that mated on bahiagrass at the field edge. Of the 157 observed-
pairs of coupled adults, 135 pairs (ca. 86%) mated on soybean, 11 pairs
(ca. 7%) mated on beggarweed, and 9 pairs (ca. 6%) mated on hairy
indigo. All matings on beggarweed and hairy indigo were observed in
1982, except for one pair on beggarweed in 1981.
A shift in mating site appeared to occur in late September, 1982.
Limited observations in late September of 1980 and 1981 prohibited the
disclosure of such a shift during those years. In 1982, the shift
appeared to be from soybean to hairy indigo. Mating occurred on soybean


64 -
well in daylight or detect human presence. Why these moths stopped
feeding and flew is unknown.
A definite preference for feeding sites at the edge of the field (
ca. 2 m) was exhibited, where ca. 57% (261 of 458 adults) of all feeding
was observed. Of the 197 observations in the field, 163 were of adult
males at human-altered feeding sites. Re-examination of the data
without these human-altered sites reveals that ca. 88% (261 of 295
adults) of all feeding occurred at the edge of the field. Due to the
strong bias of feeding at field-edge sites, and because most observation
time was spent in the field and not at the field edge, results on the
temporal occurrence of feeding should be viewed with caution. Proper
assessment of the temporal occurrence of feeding should be examined with
a separate study.
Adults fed at numerous sites (Tables 3.6-3.8). The most striking
feature about site selection was the dichotomy between male and female
sites. Although males and females shared common sites (Table 3.7), some
sites were visited strictly by males (Table 3.8). At these sites, males
were observed usually in aggregations of two or more individuals (see
Figs. 3.4 and 3.5). Of the 179 males at these sites, 159 were found in
aggregates, and 121 of these aggregated males were on aerial and sweep
nets (bags and poles). These nets were used frequently in the field
(soybean and fallow areas) to collect arthropods, were stained heavily
with arthropod and plant substances, and were coated with human sweat
and oil. The Saran Screens, additional sites of male aggregations, were
handled also by people and coated with human sweat and oil. Male
aggregations were observed only at human-altered sites and not at
naturally occurring sites. When feeding in aggregates, males were


148 -
(5) female reproductive states (see Chapter IV),
(6) egg identification (see Appendix E),
(7) egg developmental rates (see Chapter V),
(8) absolute estimates of egg density (see Chapter V), and
(9) the impact of various environmental variables on adult and egg
dynamics (see Chapters III, IV, and V).
Summary and conclusion sections for each of these experiments are
presented in respective chapters; Appendices B and E contain appropriate
discussion sections. These sections will not be repeated here in their
entirety, but important results will be discussed and highlighted in
respective order.
Adult VBC are similar in morphological appearance to another
noctuid moth, Mods latipes Guenee. Differences and similarities
between these two species are presented in Appendix B and should be
useful information to researchers encountering both (e.g., both are
caught in blacklight traps). Proper identification of VBC adults was
necessary in the present study for acquisition of data on VBC adult
numbers.
The role of the behavioral ecology study in the present work cannot
be overemphasized. Observations of adult behavior were quantified and
revealed temporal patterns in flight, mating, oviposition, and feeding.
Flight occurred primarily at night. During the day, adults resided in
the field but only after the soybean canopy had begun to close or was
closed. During the day adults flew only when disturbed or rarely if
feeding. Approximately 96% of all oviposition occurred within the first
six hours of scotophase.
Knowledge of the temporal occurrence of adult flight and residency
in the field allowed for the development of a unique adult sampling


NUMBER OF UNMATED-FEMALES/FATBODY CATEGORY
- 94 -
Figure 4.4. Total number of velvetbean caterpillar unmated adult
females per fat body content category per night.
Categories are full (fat body content full to 1/3
depleted), medium (fat body content 1/3 to 2/3 depleted)
and empty (fat body content 2/3 or more depleted). Females
were caught in a blacklight trap during 1981 at the Green
Acres Research Farm, Alachua County, FL.


195 -
Table C.9. Sample mean and standard error of weighted
observations of feeding velvetbean caterpillar
males (in aggregations) grouped by post-sunset
hour, along with the percent normalized sample mean
and standard error. Observations were made from
1980-82 at the Green Acres Research Farm, Alachua
County, FL, in a 1 ha soybean field.
Hour After
Sunset
a
n
Sample Mean of
the Weighted
Observations
( SE)
Percent Normalized^
Sample Mean
( SE)
1
19
.0105
.0105
2.27
2.27
2
19
.0307
.0205
6.63
4.42
3
16
.0628
.0358
13.55
7.72
4
13
.0291
.0291
6.27
6.27
5
10
.2796
.1533
60.37
33.09
6
5
.0000
.0000
.00
.00
7
4
.0000
.0000
.00
.00
8
3
.0505
.0505
10.90
10.90
9
10
.0000
.0000
.00
.00
10
24
.0000
.0000
.00
.00
11
22
.0000
.0000
.00
.00
12
6
.0000
.0000
.00
.00
n = number of weighted observations per sample mean; n is not
the number of feeding males. See Table C.8 for a complete
listing of all observations and observational times.
i
Percent normalized sample mean = (sample mean of weighted
observations/0.463162)*100. Percent normalized standard error
= (standard error of sample mean/0.463162)*100.


- 225
Table D.6. Mathematical description of selected physical variables (see
Table 4.1). Variable values were regressed against
blacklight trap catch data. Variable values are listed in
Tables D.7 and D.8.
Flight Temperature (C)
Flight Temp. = (ATC)*(11.9C)
where AT = mean ambient temperature C, based on data
recorded at 1 hr intervals during scotophase,
11.9C = flight threshold temperature (see Chapter III).
Vapor Pressure Deficit (mm Hg)
21.006534( 5317.030)
Vapor Pressure Deficit = (l-RH)e K
where RH = % Relative Humidity,
e = 2.71828,
K = degree Kelvin.
Equation modified from Merva (1975).
Moonlight Illuminence
Moonlight Illuminence = I*T*C,
where I = proportional moonlight intensity (see Gardiner
1968),
T = proportional time that moon was above the horizon
during the night,
C = proportional opaque cloud coverage (0 = totally
overcast, 1 = totally clear sky)(see NOAA 1981,
1982).
Wind Speed (m/s)
Wind Speed = mean wind speed, based on data recorded at 15 min
intervals during scotophase.


APPENDIX B
IDENTIFICATION OF ADULT Anticarsia gemmatalis Hubner
AND Mods latipes (Guenee)


- 263 -
Urbanus proteus (Linnaeus)
Common Names:
Bean Leafroller, Longtailed Skipper.
Family:
Hesperiidae.
Egg Development,
Color-Changes and Types:
Freshly Laid
.. Creamy white, yellowish white, off
white, whitish [Fig. E.6(A and B)].
Middle Aged
.. Same as freshly laid.
Old (Pre-Eclosion)
.. Yellowish with black larval head
capsule [Fig. E.6(C)].
Eclosed
.. Whitish [Fig. E.6(D)]. Larvae ate only
the top portion of the chorion.
Parasitized
.. Never observed.
Egg Shape: Top View
.. Circular.
Side View
.. Barrel shaped.
Ridge Number:
x SD = 11.6 0.7, range 10-13, n =
46.
Ridge Morphology:
Distinct, easy to count.
Micropylar Area:
Flat, large, circular and smooth.
Spatial Occurrence:
Laid singly but usually laid in groups
of two or three and attached to each
other.
Similar Eggs and Differences:
H. spp
Have twice as many ridges.


- 52 -
(1973) obtained similar results and found that 66%* of all mating
occurred over the same time period. Both of our results contrast
sharply with those of Leppla (1976), where 81%** of all mating for
colony adults occurred in hours 6-10 of scotophase.
The difference in Leppla's (1976) results from the results in this
study and from Greene et al. (1973) may be related to (1) colony
artifact, (2) temperature and predation, (3) moisture, or (4)
reproductive isolation. Colony adults may mate at a different time from
feral adults due to colonization. As noted above, colony adults do
behave differently than feral adults with regard to the temporal
occurrence of flight. With regard to temperature and predation, colony
adults are maintained at a constant temperature and are not exposed to
predation. Wild adults are exposed to variable and cyclic temperatures
(See NOAA 1982) and should be vulnerable to predation when mating at
certain times, as moths are highly visible and very docile. If mating
is temperature-dependent, more time will be required to complete mating
as temperature decreases during the night. Wild moths that mate in
early scotophase will complete mating before sunrise. Wild moths that
mate in late scotophase probably will not complete mating before sunrise
and will be exposed visually to predators. In a colony with constant
temperature and a lack of predation, females may "assess" the
temperature/predator risk and mate during late scotophase. Mating by
colony adults in late scotophase may favor the completion of a more
beneficial activity during early scotophase (e.g., oviposition). Also,
*Percentage value determined with calculations of data in Table 1 of
Greene et al. (1973, p. 1114).
**Percentage value determined with calculations of data in Fig. 3 of
Leppla (1976, p. 47).


MEAN EGG DENSITY MEAN EGG DENSITY
125
Figure
A.
15 -
10
hh
170 180 190 200
210 220 230 240 250 260
JULIAN DATE (1981)
35
B.
30 -
25 -
20 -
10
* i* r ? *,
}i
i i i Tj
170
180 190 200
210 220 230 240 250 260 270 280 290
JULIAN DATE (1982)
5.3. Mean densities per .91 m-row ( 95% confidence interval) of
freshly-laid VBC eggs on soybean at the Green Acres
Research Farm, Alachua County, FL: (A) 1981, and (B) 1982.


110
Table 4.8. Regression equations of total daily number of velvetbean
caterpillar moths in the field and total nightly smoothed
number of moths caught in the blacklight trap (BLT) during
1982 at the Green Acres Research Farm, Alachua County, FL.
Total number of moths (females, males, and total adults)
were determined with adult trap-cage data. BLT data were
smoothed with a nonlinear data smoothing algorithm (3RSSH,
twice) based on running medians (see Velleman 1980, Ryan et
al. 1982).
Female
FF = -68.55 + 30.06 (FBLT),
where r2 = .43,
FF = total number of field females,
FBLT = smoothed number of BLT females.
Male
MF = -218.40 + 31.10 (MBLT)
where r2 = .50,
MF = total number of field males,
MBLT = smoothed number of BLT males.
Adult
AF = 340.74 + 31.66 (ABLT)
where r2 = .55,
AF = total number of field adults,
ABLT = smoothed number of BLT adults.


MEAN EGG DENSITY
Figure 6.2. Kean velvetbean caterpillar egg density per .91 m-row of soybean during 1982 in a 1 ha
field at the Green Acres Research Farm, Alachua County, FL. Estimated density with 95%
confidence intervals determined from field collected data. Upper and lower values of the
confidence intervals are represented as hypens. Predicted density determined with model
simulations. Ovipositional rate was a constant during the simulation.
138


27
decrease significantly after canopy closure because closed canopies are
darker than unclosed canopies and predators may not be able to see as
well in a closed canopy.
The completion of the present review of the ecology of soybean and
VBC, and their interactions, sets the stage for presentation of the
chapters that follow. In the next chapter (Chapter III), a description
of the behavioral ecology of adult VBC within soybean is presented.
Observations of adult behavior in the field were necessary for the
design and implementation of the experiments presented in the chapters
that follow Chapter III.


117
Figure 5.1. Eggs of the velvetbean caterpillar: (A) "freshly-laid"
egg, light green in color, (B) "middle-aged" egg, light
green in color with brownish-red speckles, and (C)
"brownish" egg (i.e., about to hatch), light brown in
color.


249 -
Figure E.2 (continued)


TABLE OF CONTENTS
PAGE
ACKNOWLEDGEMENT S v
LIST OF TABLES xiii
LIST OF FIGURES xvi
ABSTRACT xix
CHAPTERS
I INTRODUCTION 1
II LITERATURE REVIEW 6
Introduction 6
Soybean Ecology 6
General Description 7
Development and Growth 8
Water Stress 13
Susceptibility to Insect Attack 13
Velvetbean Caterpillar Ecology 14
Distribution 14
Life Stages 15
Life History 16
Adult Behavior 16
Host Plants 17
Natural Enemies 23
Sampling and Economic Thresholds 23
Models 23
Velvetbean Caterpillar as a Soybean Pest 24
Velvetbean Caterpillar/Soybean Interactions 25
III BEHAVIORAL ECOLOGY OF ADULT VELVETBEAN CATERPILLAR 28
Introduction 28
- ix -


Table 2.4 (continued)
g
The authenticity of many of these records is questionable because they were not accompanied with (1)
host scientific name, (2) confirmation of oviposition, (3) verification of complete larval development,
(4) verification of larval and host identities, and (5) multiple sightings.
^Host records on file at Florida Department of Agriculture and Consumer Services, Division of Plant
Industry (DPI), Gainesville, FL 32611.
c
D. C. Herzog, Professor, Entomology and Nematology Department, University of Florida, Agriculture and
Education Center, Quincy, FL 32351.
^J. W. Todd, Assoc. Professor, Department of Entomology, University of Georgia, Georgia Coastal Plain
Experiment Station, Tifton, GA 31794.
0
Author unknown.
i
ho
ro
l


Copyright 1986
by
Ben Gregory, Jr


- 37
(11.2 0.6 days). At 26.7C unmated females lived longer (22.8 0.8
days) than mated females (18.0 1.0 days). As temperature increased
from 21.1 to 32.2C, mated females laid the majority of their eggs at
progressively earlier ages. At all temperatures, 50% of all oviposition
occurred within four to nine days after emergence and steadily declined
thereafter.
Females reared from larvae maintained on different soybean
phenological stages exhibited variation in mean total oviposition, mean
percent egg hatch, mean longevity and Rq (Moscardi et al. 1981b). "Mean
oviposition-rates ranged from 963.4 to 515.0 eggs/female when larvae fed
on early vegetative and senescent leaves, respectively. Average daily-
oviposition peaked ca. 4 days after adult emergence, decreased sharply
to day 10, and remained at a low level until adult mortality. Mean
daily egg-hatch decreased with female age, but female longevity was not
affected significantly" (Moscardi et al. 1981b, p. 113).
Using a pivoted-stick actograph, Wales (1983) confirmed that mated
females lay most of their eggs early in life. Unmated females delayed
oviposition until very late in life. The hourly distribution for lab
mated and wild mated females, ages one to nine days old, indicated that
most eggs were laid in the first four hours of scotophase, but that
oviposition occurred all night.
Feeding
Not much is known about adult feeding in the field. Hinds (1930)
reported adults fed on the nectar of a Crotalaria sp. Greene et al.
(1973, p. 1115) observed feeding during all hours of scotophase, "with
peak activity from sundown to after 12:00 midnight [sic]." Primarily
females, but also some males, fed on crushed grapes from sunset until
0230 when observations stopped. Adults fed at the seed heads of


- 251
scabra Approximately half the number of
ridges, ridges protrude well above egg
surface.


68
Figure 3.4. Aggregation of velvetbean caterpillar males on an aerial
net. Males are feeding at the surface of the net (bag and
pole). Photograph was made in a 1 ha soybean field at the
Green Acres Research Farm, Alachua County, FL, September 7,
1983.


- 8 -
(Buchanan 1980) comb, nov.* (see Weiss 1983). From a study on the
partitioning of C14 photosynthate in soybean, Housely et al. (1979)
speculate that less carbon is channeled into amino acids of nodulated
plants, as opposed to non-nodulated plants. The significance of this
channeling is unclear, but perhaps nodulated soybean can channel more
carbon into seed formation and plant defense.
Development and Growth
Fehr and Caviness (1977) describe and illustrate the stages of
soybean development based on vegetative and reproductive states (Tables
2.1 and 2.2). Soybean is a short-day plant, and reproduction (or
flowering) is triggered by photoperiod (Garner and Allard 1930).
Temperature and variety can be important in determining the beginning of
flowering (van Schaik and Probst 1958, Fehr and Caviness 1977).
Flowering occurs over a four to six-week period (Shibles et al. 1975).
Flowers are self-pollinated (Shibles et al. 1975, McGregor 1976), but
Erickson (1975) demonstrated a significant yield increase in two
varieties due to honey-bee, Apis mellifera L., pollination. Soybean
flowers do produce nectar (Jaycox 1970) and possess most, if not all, of
the anatomical adaptations of entomophilious plants (e.g., the nectar
guide)(Erickson and Garment 1979).
Soybean exhibits two types of growth habit, determinate and
indeterminate. Canopies of these two growth types are distinctly
different. The largest leaves of indeterminates occur at the center of
the plant, with gradations in size toward each end of the stem. With
determinate cultivars, all mature leaves above the middle of the plant
*Synonym is Rhizobium japonicum Buchanan (Jordon 1982).


182
Table C.5 (continued)
Date3
(D-M-Y)
Hour After
Sunset
Number of
Observations
of Oviposition
c
Observational
Time (min)
Weighted*^
Observations
Ol-S-81
12
0
14
0.000000
04-S-81
12
0
19
0.000000
08-S-81
12
0
25
0.000000
15-S-81
12
0
38
0.000000
aD-M-Y =
Day, Month,
Year; A = August, S
= September; 81
= 1981,
82 = 1982.
^Total number of observations of oviposition was 121.
c
Total number of observational minutes was 4417.
^Weighted Observations = Number of Observations
Observational Time


Discussions about personal and career goals with Dale Habeck, John
Strayer, Don Hall, Jim Lloyd, and Dan Shankland were invaluable.
I thank Jim Jones for suggesting that I write my model with SAS and
I am indebted to Ramon Littel, Ken Portier, Mark Yang, Victor Chew,
Partha Lahiri, and Greg Pepples for their statistical expertise. I also
owe thanks to Niklaus Hostettler and the legions of CIRCA consultants
that helped me with my SAS programs.
I owe very special thanks to Anne Keene for typing my dissertation
and for her enduring abilities to type both night and day. The
completion of my dissertation would have been impossible without her
assistance. She is a superb typist and frequently went out of her way
to accommodate my schedule. She loves hard work and will not stop until
the job is done. Anne has a real zest for life and is a very special
person. The world needs more people like Anne.
Margie Niblack drew most of the figures in my dissertation, as well
as my M.S. thesis. Working with her has always been fun. Margie is an
excellent artist/illustrator, works very hard, and is seemingly
tireless. Her willingness to help me with my graphics whenever possible
will always be appreciated. I will miss her warm personality, sweet-
naturedness and generous heart.
I would like to thank Laura Line Reep for drawing three of the
figures in my dissertation. Mary Crume of the Graduate School completed
a mechanical critique of my dissertation. The time and effort she spent
completing her excellent critique have been appreciated very much.
In far too many ways to mention, my work and life have been
enriched by the friendship and help of Paul Wales, Kris Elvin, Bob
O'Neil et al., Jane and Ken Cundiff, Debi Waters, Nancy Phillips, Carol
- vii


77
scotophase. A male-prey bias exists, as 20 of 26 prey were males; adult
VBC sex-ratio was ca. 1:1 (see Chapter IV). The nature of this bias is
unknown but may be due to aggressive chemical mimicry of VBC mating-
pheromone by some or all of these spiders (see Foelix 1982).
Most of the predation records, 17 out of 26 (65%), were of P.
viridens. Fourteen of these records occurred between 2047 and 0136, the
time period when VBC adults were most active. Misumenops spp. accounted
for 5 of the 26 records (19%) and the orbweavers accounted for 4 of the
26 records (15%). The large number of P. viridens records may be a
reflection of where observation time was concentrated (i.e., in the
field). Also, the webs of orbweavers were destroyed frequently by
research personnel walking through the field. Figures 3.8 and 3.9 are
photographs of two spider predation records.
Conclusions
The temporal patterns of several adult activities (flight, mating,
oviposition, and feeding) were observed and quantified in the present
study, as were some environmental factors that affected these patterns.
The suspected adaptive significance of these activity patterns was
discussed. Flight occurred primarily at night. During the day, adults
resided in the field but only after the soybean canopy had begun to
close or was closed. During the day adults flew only when disturbed or
rarely if feeding. Approximately 79% of all mating occurred within the
first four hours of scotophase. Mating occurred usually at the top of
soybean plants, a height of ca. .8 m. Placement of pheromone traps near
the canopy top in the field would result probably in the largest capture
of males. Approximately 96% of all oviposition occurred within the
first six hours of scotophase and feeding occurred primarily at night.
Females utilized nutritional sources that may have affected egg


1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
184 -
Total oviposition per female at four different
temperatures. Datum at 11.9C is from field
observation at Green Acres Research Farm, Alachua
County, FL. Data of 21.1, 23.9, and 26.7C are
from Moscardi et al. (1981b) and were stored on
computer cards at the time of this analysis in
Building 175, Insect Population Dynamics
Laboratory, University of Florida, Alachua County,
Gainesville, FL.
Total Oviposition/Female/Temperature(C)
21.1
23.9
26.7
448
1508
728
520
912
1256
428
412
1384
600
392
608
640
324
296
372
940
620
296
352
1696
348
268
664
612
540
604
472
1744
608
228
284
1872
796
440
672
744
548
596
364
1448
584
176
348
1080
732
748
936
660
460
648
468
1504
784
236
444
1360
484
356
584
572
1976
912
388
1804
528
384
560
512
1644
324
644
488


- 278
Table G.2. Data set (DM0DEL81.DAT) for 1981 model of adult and egg
populations of velvetbean caterpillar. See the comment
statements in Table G.l for definitions of the column
headings.
JULIAN
FBLT
LB05
EEGG
UB05
SOY
173
0
0.00
0.00
0.00
1
174
0

1
175
0

1
176
0
0.00
0.00
0.00
1
177
0



1
178
0



1
179
0


1
180
0
0.00
0.00
0.00
2
181
0



2
182
0



2
183
0


2
184
0



2
185
0



2
186
0



2
187
0
0.00
0.00
0.00
3
188
0



3
189
0



3
190
0
0.00
0.00
0.00
4
191
0



4
192
0



4
193
0


4
194
0
0.00
0.00
0.00
5
195
0



5
196
0



5
197
0
0.00
0.00
0.00
6
198
0


6
199
0



6
200
0



6
201
0
0.00
0.00
0.00
7
202
0



7
203
1



7
204
0
0.00
0.94
2.79
7
205
1


7
206
0



7
207
0


7
208
1
0.00
0.81
1.92
11
209
1



11
210
0



11
211
0
0.00
0.40
1.20
11
212
0



11
213
1



11
214
0



11


TOTAL NUMBER/NIGHT TOTAL NUMBER/NIGHT TOTAL NUMBER/NIGHT
- 89 -
JULIAN DATE
Figure 4.2. Total number of velvetbean caterpillar moths captured in a
blacklight trap per night in a 1 ha soybean field at the
Green Acres Research Farm, Alachua County, FL: (A) 1980,
(B) 1981, and (C) 1982.


55
Table 3.2. Estimates of the absolute density of adult females
of the velvetbean caterpillar in a soybean field.
Density was determined with an adult trap-cage
(see Chapter IV) in 1982 at the Green Acres
Research Farm, Alachua County, FL.
Absolute Density
Date of Adult Females
(number/.87 ha)
July 15
0
July 22
0
July 29
0
August 5
416.8
August 12
347.3
August 19
416.8
August 26
1806.2
September
2
2570.4
September
9
2292.5
September
16
694.7
September
23
764.1
September
30
208.4
October 7
347.3
October 14
416.8


5
and egg population model. The objective of this model is to mimic the
number of eggs laid by VBC adults in a 1 ha soybean field. To
accomplish this objective, experiments were conducted to understand or
quantify (1) egg identification, (2) egg developmental rates, (3)
estimates of the absolute density of eggs, (4) adult identification, (5)
observations of adult behavior in the field, (6) estimates of the
relative and absolute densities of adults, (7) categories of female
reproductive states, and (8) the impact of various environmental
variables (e.g., temperature) on adult and egg dynamics. Experimental
methods, results, and discussions are presented in the chapters and
appendices that follow.
Chapter II is a general review of soybean ecology, VBC ecology, and
VBC/soybean interactions. Chapter III is a study on the field behavior
of adult VBC. Chapter IV is a study on sampling for adults, of the
relationships between adult density and selected environmental
variables, and of the determination of female reproductive categories.
In Chapter V, an egg sampling technique and egg density data are
presented. In Chapter VI, a model of VBC adult and egg populations is
presented, and Chapter VII contains the summary and conclusions.


175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
- 282
Data set (DMODEL82.DAT) for 1982 model of adult and egg
populations of velvetbean caterpillar. See the comment
statements in Table G.3 for definitions of the column
headings.
FBLT
LB05
EEGG
UB05
SOY
0
0.00
0.00
0.00
1
0

1
0

1
0

1
0
0.00
0.00
0.00
1
0

1
0

1
0
0.00
0.00
0.00
2
0

2
0

2
0

2
0
0.00
0.00
0.00
3
0

3
0

3
0
0.00
0.09
0.27
4
0

4
0

4
0

4
1
0.00
0.00
0.00
5
1

5
0

5
2
0.00
0.00
0.00
5
0

5
0

5
0

5
0
0.00
0.27
0.58
6
1

6
0

6
0
0.00
0.18
0.43
7
4

7
2

7
1

7
2
0.00
0.45
0.92
8
1 '

8
0

8
2
1.20
2.27
3.35
10
4
10
6
10
5
10
2
2.21
3.55
4.88
11
0
11
2
11


176 -
Table C.3 (continued)
Date3
(D-M-Y)
Hour After
Sunset
Number of
Observations
of Mating
Q
Observational
Time (min)
Weighted*^
Observations
28-A-81
11
0
60
0.000000
Ol-S-81
11
0
60
0.000000
04-S-81
11
0
60
0.000000
08-S-81
11
0
60
0.000000
13-S-81
11
0
6
0.000000
15-S-81
11
0
51
0.000000
31-A-82
11
1
36
0.027778
14-S-82
11
0
8
0.000000
18-S-82
11
0
23
0.000000
21-S-82
11
0
17
0.000000
25-S-82
11
0
32
0.000000
25-A-81
12
0
2
0.000000
28-A-81
12
0
7
0.000000
Ol-S-81
12
0
14
0.000000
04-S-81
12
0
19
0.000000
08-S-81
12
0
25
0.000000
15-S-81
12
0
38
0.000000
aD-M-Y = Day, Month, Year; A = August, S = September; 80 = 1980,
81 = 1981, 82 = 1982.
b
c
d
Total number of observations of mating was 157.
Total number of observational minutes was 5162.
Number of Observations
Weighted Observations =
Observational Time


APPENDIX C
BEHAVIORAL OBSERVATIONS:
QUANTITATIVE TECHNIQUE AND DATA


244 -
Figure E.l (continued)


LIST OF FIGURES
PAGE
Figure 3.1. Mating pair of adult velvetbean caterpillar
on a soybean leaflet 48
Figure 3.2. The percent-normalized sample mean ( SE) of
each post-sunset hour for activities of adult
velvetbean caterpillars 52
Figure 3.3. Linear relationship between total eggs per
velvetbean caterpillar adult female and
temperature 59
Figure 3.4. Aggregation of velvetbean caterpillar males
on an aerial net 68
Figure 3.5. Aggregation of velvetbean caterpillar males
on the screen of an insectary 69
Figure 3.6. Adult velvetbean caterpillar feeding at the
surface of a bahiagrass raceme 71
Figure 3.7. Adult velvetbean caterpillar feeding at the
surface of a dead soybean leaflet 72
Figure 3.8. Green lynx spider [Peucetia viridans (Hentz)]
preying on an adult male velvetbean caterpillar 78
Figure 3.9. Orbweaver spider (Acanthepeira sp.) preying on
an adult female velvetbean caterpillar 79
Figure 4.1. Trap-cage used to collect adult velvetbean
caterpillar in a 1 ha soybean field during 1982
at the University of Florida's Green Acres
Research Farm, Alachua County, FL 84
Figure 4.2. Total number of velvetbean caterpillar moths
captured in a blacklight trap per night in a
1 ha soybean field at the Green Acres Research
Farm, Alachua County, FL 89
Figure 4.3. Total number of adult velvetbean caterpillar
females per reproductive category per night 93
- xv i -


- 31
Douglas (1930) indicated that adults were night-flying moths, were
inactive in soybean during the day and, if disturbed, exhibited a very
swift flight. Ellisor (1942, p. 18) noted:
The moths are inactive in the day, usually resting on the ground or
close to the ground on leaves or other debris, and when disturbed
make darting flights for short distances and again become inactive.
Late in the afternoon they become active and can be seen darting in
and out of the plants.
The most detailed observations of flight were reported by Greene et
al. (1973). Moths were observed with a flashlight and a propane lantern
in a 1.83 x 1.83 x 3.66 m screen cage placed over soybean plants in a
field. "Observation of moths in daylight showed undirected flight
behavior. Disturbed moths flew into the cage walls, hit leaves and
other objects, and flew in undirected, sharp, angled patterns, similar
to the observations by Ellisor (1942). At sunset, moth activity in the
field was minor, but 30 min post-sunset, moth movement became directed,
slower, and much more controlled. Moths did not fly into the cage
walls; they would fly to the wall and light upon it; they would fly to a
leaf, flutter, and settle upon it, and they were observed not to bump
into objects. Moths on the cage walls at sundown moved to the plants
and by ca. lj h postsundown few were left on the cage walls" (Greene et
al. 1973, p. 1113).
Another report of flight activity in soybean was made by Gutierrez
and Pulido (1978). They reported that moths were fast fliers and flew
regularly during the night. During the day, moths remained on the soil
surface near the soybean plants or on the middle part of the plants.
Johnson et al. (1981) reported on the flight of colony males under
natural photoperiod in screenwire cages in a greenhouse; females were
present but were unable to fly. "Males became active ca. 45 min after


129 -
"compared" with the number of eggs laid during that same night and
because the VBC submodel in the SICM model operates on a daily
resolution. Construction on the same temporal and spatial resolution as
the VBC submodel was necessary if the adult egg population model is to
be incorporated into the dynamics model. Sampling and manpower
constraints restricted the estimation of field egg density to
twice-a-week intervals. Consequently, model predictions of egg density
are compared to field estimates at twice-a-week intervals. Data
required for model structure, determination of parameters, comparison of
model behavior, and validation were acquired from the completion of nine
separate experiments in the following areas:
(1) adult identification (see Appendix B),
(2) observation of adult behavior in the field (see Chapter III),
(3) relative estimates of adult density (see Chapter IV),
(4) absolute estimates of adult density (see Chapter IV),
(5) female reproductive states (see Chapter IV),
(6) egg identification (see Appendix E),
(7) egg developmental rate (see Chapter V),
(8) absolute estimates of egg density (see Chapter V), and
(9) monitoring of various environmental variables (see Chapters
III, IV, and V).
Sampling for adults would have been impossible without proper adult
identification. Behavioral observations of adults in the field revealed
temporal patterns in flight and oviposition. Knowledge of these
patterns was necessary for the development of adult and egg sampling
methodologies and for the acquisition of adult and egg density


12 -
Table 2.3. Average and range of developmental time required for a
soybean plant to develop between stages (Fehr and Caviness
1977).
Stage
Average3
Developmental Time
(day)
Range in*5
Developmental Time
(day)
0C VE
10
5
-
15
VE VC
5
3
-
10
VC VI
5
3
-
10
VI V2
5
3
-
10
V2 V3
5
3
-
8
V3 V4
5
3
-
8
V4 V5
5
3
-
8
V5 V6
3
2
-
5
R1 R2
0d, 3
0
-
7
R2 R3
10
5
-
15
R3 R4
9
5
-
15
R4 R5
9
4
-
26
R5 R6
15
11
-
20
R6 R7
18
9
-
30
R7 R8
9
7
-
18
Average total developmental time is 125 days.
^Range varies from 74 to 218 days.
q
0 = planting
dRl and R2 generally occur simultaneously in determinate varieties.
The time interval between R1 and R2 for indeterminate varieties is
about three days.


109 -
Table 4.7. Regression equations of total daily number of velvetbean
caterpillar moths in the field and total nightly number of
moths caught in the blacklight trap during 1982 at the Green
Acres Research Farm, Alachua County, FL. Total number of
moths (females, males, and total adults) were determined
with adult trap-cage data.
Female
FF = 134.11 + 23.20 (FBLT),
where r2 = .26
FF = total number of field females,
FBLT = total number of BLT females.
Male
MF = 26.40 + 16.81 (MBLT)
where r2 = .28,
MF = total number of field males,
MBLT = total number of BLT males.
Adults
AF = 129.25 + 20.20 (ABLT)
where r2 = .32,
AF = total number of field adults,
ABLT = total number of BLT adults.


- 234 -
Table D.8 (continued)
Vapor
Press.
Calendar Julian Flight Deficit
Date Date Temp. (C) (mm Hg)
21
264
9.95
.208
22
265
4.58
.673
23
266
4.91
.233
24
267
7.27
.578
25
268
4.67
.218
26
269
3.29
.343
27
270
5.60
.512
28
271
7.31
.918
29
272
9.91
.680
30
273
10.04
.035
1
274
7.68
.577
2
275
7.41
.284
3
276
9.58
.576
4
277
10.51
.818
5
278
10.55
.000
6
279
11.06
.691
7
280
8.38
.882
8
281
9.77
1.600
9
282
9.26
1.069
10
283
11.34
1.847
11
284
9.35
.629
12
285
8.89
2.033
13
286
8.53
1.088
14
287
3.31
1.014
15
288
0.00
.907
16
289
0.00
.291
17
290
3.40
1.589
18
291
2.72
.470
19
292
4.21
.853
Moonlight Barometric
Intensity
Rainfall
Press. (MB)
.0000
.0000
1013.93
.0086
.0000
1017.93
.0020
.0000
1018.17
.0172
.0000
1013.95
.0000
.1472
1015.03
.1061
.0000
1011.68
.1584
.0000
1015.91
.2324
.0000
1016.68
.0132
.0000
1016.18
.0188
.0000
1015.76
.2394
.0000
1013.74
.9310
.0000
1013.17
.6256
.0000
1013.71
.3513
.0000
1014.42
.0237
.0000
1018.45
.2838
.0000
1018.89
.2056
.0000
1016.83
.1276
.0000
1014.28
.0700
.0000
1013.71
.0420
.0000
1013.64
.0150
.0000
1015.99
.0080
.0000
1015.65
.0014
.0000
1013.49
.0029
.0000
1014.51
.0002
.0000
1014.32
.0000
.0000
1016.72
.0000
.0000
1021.34
.0000
.0000
1021.04
.0023
.0000
1021.04


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AGREEMENT_INFO ACCOUNT UF PROJECT UFDC
FILES


- 232 -
Table D.8
. Values of physical variables regressed
trap catch data (1982). Mathematical
physical variables are listed in Table
against blacklight
descriptions of
D.6.
Calendar
Date
Julian
Date
Flight
Temp. (C)
Vapor
Press.
Deficit
(mm Hg)
Moonlight
Intensity
Rainfall
Barometric
Press. (MB)
July 27
208
10.98
.124
.0066
.0000
1016.95
28
209
10.73
.399
.0440
.0000
1016.69
29
210
10.37
.978
.0707
.0000
1019.76
30
211
10.73
.967
.1819
.0000
1021.74
31
212
12.04
1.197
.2598
.0000
1018.99
Aug. 1
213
11.89
2.099
.4063
.0000
1017.22
2
214
12.34
.433
.4914
.0000
1014.62
3
215
10.68
.574
.6650
.0000
1014.38
4
216
10.63
.882
.6900
.0000
1016.57
5
217
9.31
.109
.6570
.0000
1017.96
6
218
8.40
.000
.5817
.0000
1018.80
7
219
11.28
.363
.3720
.0000
1019.13
8
220
11.64
1.675
.0439
.0000
1018.94
9
221
11.08
.524
.0077
.0000
1020.16
10
222
8.91
.752
.1387
.0000
1021.05
11
223
10.47
.966
.0972
.0000
1019.39
12
224
11.53
.874
.0693
.0000
1017.11
13
225
11.79
.235
.0292
.0000
1015.84
14
226
10.17
.104
.0076
.0000
1015.25
15
227
11.94
1.910
.0079
.0000
1016.27
16
228
11.48
.338
.0029
.0000
1016.20
17
229
10.32
.403
.0003
.0000
1015.24
18
230
9.82
.000
.0000
.0000
1015.30
19
231
10.42
.000
.0000
.0000
1019.74
20
232
10.78
.425
.0000
.0000
1020.18
21
233
10.92
.000
.0005
.0000
1017.25
22
234
11.39
.059
.0036
.0000
1017.71


SEX RATIO/NIGHT SEX RATIO/NIGHT
JULIAN DATE JULIAN DATE
Figure 4.9. Sex ratio of velvetbean caterpillar adults caught in blacklight traps (BLT) and an adult
trap-cage (ATC) in a 1 ha soybean field at the Green Acres Research Farm, Alachua County,
FL: (A) 1980, BLT, (B) 1981, BLT, (C) 1982, BLT, and (D) 1982, ATC. Dashed line in all
graphs represents the seasonal mean sex ratio.
103


169 -
Table C.l. Artificial data of an adult activity and the
technique for determination of the temporal
frequency of that activity during scotophase
calculation of the weighted observations for a
particular day.
Hour After
Sunset
Number of
Observations
Observational
Time (min)
Weighted
Observations
(obs./min)
1
1
30
.03
2
6
60
.10
3
6
30
.20
4
2
60
.03
5
1
60
.02
6
0
0
.00
7
0
0
.00
8
0
0
.00
9
0
60
.00
10
0
45
O
o

11
0
45
.00
12
0
30
.00
Weighted Observations
Number of Observations
Observational Time


177
Table C.4. Sample mean and standard error of the weighted
observations of mating velvetbean caterpillar
adults are grouped by post-sunset hour, along with
the percent normalized sample mean and standard
error. Observations were made from 1980-82 at the
Green Acres Research Farm, Alachua County, FL, in a
1 ha soybean field.
Hour After
Sunset
a
n
Sample Mean of
the Weighted
Observations
(SE)
Percent Normalized^
Sample Mean
(SE)
1
16
.0280
.0185
9.60
+
6.36
2
16
.0646
.0288
22.15
+
9.87
3
15
.0709
.0208
24.31
+
7.13
4
14
.0676
.0183
23.19
+
6.27
5
10
.0080
.0056
2.73
+
1.94
6
5
.0258
.0132
8.84
+
4.52
7
4
.0119
.0119
4.08
+
4.08
8
3
.0101
.0101
3.46
+
3.46
9
10
.0019
.0019
.66
+
. 66
10
17
.0009
.0010
.34
+
.34
11
15
.0019
.0019
.64
+
.64
12
6
.0000
.0000
.00
+
.00
n = number of weighted observations per sample mean; n is not
the number of mating observations. See Table C.3 for complete
listing of all observations and observational times.
Percent normalized sample mean = (sample mean of weighted
observations/0.291516)*100. Percent normalized sample mean =
(standard error of sample mean/0.291516)*100.


Table C.8 (continued)
Da te
(D-M-Y)
u b
Hour
MaleC
Agg
Male**
OAgg
Hale*
All
Female*
Adult8
HFA*'
Agg
HFA1
OAgg
Time
10-S-82
5
0
0
0
0
0
0
0
19
24-S-82
5
0
0
0
0
0
0
0
37
25-S-82
5
0
0
0
2
0
2
2
18
16-A-81
6
0
7
7
5
3
15
15
55
23-A-81
6
0
1
1
1
0
2
2
A2
13-S-81
6
0
0
0
0
0
0
0
AA
OA-S-82
6
0
0
0
0
0
0
0
60
25-S-82
6
0
0
0
3
0
3
3
60
16-A-81
7
0
0
0
0
3
3
3
30
13-S-81
7
0
0
0
0
0
0
0
21
OA-S-82
7
0
0
0
0
0
0
0
11
25-S-82
7
0
0
0
0
0
0
0
3
16-A-81
8
0
0
0
2
2
A
A
60
13-S-81
8
0
2
2
3
0
5
5
39
25-S-82
8
5
2
7
6
0
13
8
33
16-A-8I
9
0
4
A
3
1
8
8
60
13-S-81
9
0
0
0
2
0
2
2
60
28-A-82
9
0
1
1
1
0
2
2
27
31-A-82
9
0
0
0
0
0
0
0
2A
Weight** Weight* Weight01 Weight Weight Weight*1 Weight**
1 2 3 A 5 6 7
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.151515
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.127273
0.023810
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.051282
0.060606
0.066667
0.000000
0.037037
0.000000
0.000000
0.000000
0.000000
0.127273
0.023810
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.051282
0.212121
0.066667
0.000000
0.037037
0.000000
0.000000
0.000000
0.111111
0.090909
0.023810
0.000000
0.000000
0.050000
0.000000
0.000000
0.000000
0.000000
0.033333
0.076923
0.181818
0.050000
0.033333
0.037037
0.000000
0.000000
0.000000
0.000000
0.054545
0.000000
0.000000
0.000000
0.000000
0.100000
0.000000
0.000000
0.000000
0.033333
0.000000
0.000000
0.016667
0.000000
0.000000
0.000000
0.000000
0.000000
0. 111 111
0.272727
0.047619
0.000000
0.000000
0.050000
0.100000
0.000000
0.000000
0.000000
0.066667
0.128205
0.393939
0.133333
0.033333
0.074074
0.000000
0.000000
0.000000
0.111111
0.272727
0.047619
0.000000
0.000000
0.050000
0.100000
0.000000
0.000000
0.000000
0.066667
0.128205
0.242424
0.133333
0.033333
0.074074
0.000000


DEVELOPMENTAL RATE (I/HOUR)
121
Figure 5.2. Developmental rate of speckling in VBC eggs at six
different temperatures. Both colony and wild eggs were
studied at 26.7C. Developmental zero (DZ) for speckling
was 12.25C, and 153.27 degree-hours were required for
speckling to occur. Mean estimates are shown in the figure
for ease of view.


215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
- 279 -
(continued)
FBLT
LB05
EEGG
UB05
SOY
0
0.00
0.81
1.92
11
1
11
1
11
2
0.00
0.40
1.20
11
2

11
2

11
3

11
2
0.56
2.42
4.29
12
0

12
0

12
4
0.24
2.42
4.60
12
3

12
4

12
1

12
7
2.04
5.73
9.43
12
9

12
15

12
8
1.35
5.65
9.96
13
6
13
5
13
12
13
4
0.55
2.87
5.18
14
10
14
3
14
7
2.89
6.06
9.23
14
14

14
22

14
8

14
3
2.61
5.74
8.86
15
14
15
21
15
18
3.59
6.87
10.14
15
11
15
18

15
21

15
6
3.32
7.67
12.03
15
10
15
16
15
20

15
18

15
37

15
14
15
30
8.12
12.29
16.46
16


Table D.l. Total number of females, males, and adults (male and
females) caught in a blacklight trap in 1980 at the
Green Acres Research Farm, Alachua County, FL. Trap
did not operate on dates 203, 207, 220, 225, 232, 236,
250, 251, and 254.
Total Number
Calendar Julian
Date Date Females Males Adults
4
186
0
0
0
5
187
0
0
0
6
188
0
0
0
7
189
0
0
0
8
190
1
0
1
9
191
0
0
0
10
192
0
0
0
11
193
0
0
0
12
194
2
0
2
13
195
0
0
0
14
196
0
0
0
15
197
0
0
0
16
198
0
1
1
17
199
0
1
1
18
200
0
1
1
19
201
0
0
0
20
202
0
0
0
21
203
-
-
-
22
204
1
1
2
23
205
2
0
2
24
206
0
3
3
25
207
-
-
-
26
208
0
2
2
27
209
0
1
1
28
210
0
2
2
29
211
1
2
3
30
212
1
3
4
203


CHAPTER V
MEASUREMENT OF EGG DENSITY
Introduction
Velvetbean caterpillar (VBC) larvae are a major defoliators of
soybean in the Gulf Coast area of the United States (Herzog and Todd
1980). Adult VBC immigrate into soybean fields annually and pest
problems result from oviposition by females and eclosin of larvae (see
Ellisor 1942, Greene 1976, Herzog and Todd 1980, Buschman et al. 1981a,
1981b). As is the case for most pests, current management of VBC is
directed at the symptoms of the pest problem (i.e., controlling larvae)
and not the cause (i.e., sources of adults)(see Barfield and O'Neil
1984). Not surprisingly, virtually nothing is known about the timing
and magnitude of adult movement or oviposition in soybean (see Rabb and
Kennedy 1979, MacKenzie et al. 1985). Wilkerson et al. (1982) used a
soybean/VBC dynamics model to describe how variation in the timing and
magnitude of adults resulted in notable differences in soybean yield and
grower profit (from -$289.63 to $178.43, see Table 1.1). Adult and egg
densities used in the model were determined from estimated larval
densities (Stimac,* personal communication). Examination of adult
*J. L. Stimac, Associate Professor, Department of Entomology and
Nematology, University of Florida, Gainesville, FL. 32611. Larval
densities at time "t" were used to determine egg and adult densities at
time "t-1" by calculating the densities of adults and eggs required to
produce the known larval densities. Mortality values of adults and
eggs were used in these calculations.
113


Table 3.1. Amount of time dedicated to behavioral observation of adult velvetbean caterpillar in a 1
ha soybean field at
the Green
Acres
Research
Farm, Alachua
County,
FL, from
1980-82.
Month
Scotophase
Time
Observation
(min)
Photophase^
Time
Observation
(min)
Total
Observation
Time (min)
1980C
1981
1982
Total
1980C
1981
1982
Total
June
0
180
359
539
0
90
630
720
1259
July
0
609
1080
1689
0
876
3481
4357
6046
Aug.
180
2159
1158
3497
0
2489
1735
4224
7721
Sept.
0
1717
1401
3118
10
335
1894
2239
5357
Oct.
0
0
350
350
0
30
509
539
889
Total
(min)
9193
12079
21272
Total
(hr/min)
153/13
201/19
354/32
Scotophase was sunset to sunrise.
kphotophase was sunrise to sunset,
c
In 1980, most of the observation times were not recorded.


Table D.3 (continued)
Number of Females
Number of Males
Number of Total
Adults
Calendar
Julian
Date
Date
Total Smoothed Weighted
Total Smoothed Weighted
Total Smoothed
Weighted
Aug. 30
242
106
79.25
0.34
121
82.76
0.46
227
157.30
0.44
31
243
75
81.64
-0.08
88
86.57
0.02
163
163.42
0.00
Sept. 1
244
97
80.69
0.20
97
84.07
0.15
194
161.28
0.20
2
245
75
77.10
-0.03
75
77.73
-0.04
150
153.59
-0.02
3
246
75
69.58
0.08
68
69.65
-0.02
143
139.95
0.02
4
247
50
61.20
-0.18
59
64.05
-0.08
109
125.47
-0.13
5
248
53
56.57
-0.06
63
60.91
0.03
116
115.58
0.00
6
249
62
55.58
0.12
63
58.59
0.08
125
112.38
0.11
7
250
41
56.21
-0.27
53
57.84
-0.08
94
114.18
-0.18
8
251
72
59.86
0.20
35
57.63
-0.39
107
118.57
-0.10
9
252
52
65.23
-0.20
84
55.13
0.52
136
121.94
0.12
10
253
141
67.59
1.09
62
49.71
0.25
203
120.72
0.68
11
254
81
64.89
0.25
37
41.19
-0.10
118
110.27
0.07
12
255
43
57.60
-0.25
28
32.55
-0.14
71
92.67
-0.23
13
256
33
50.52
-0.35
27
27.78
-0.03
60
78.53
-0.24
14
257
57
46.99
0.21
50
26.28
0.90
107
71.16
0.50
15
258
51
44.82
0.14
24
26.39
-0.09
75
67.72
0.11
16
259
39
41.67
-0.06
27
26.52
0.02
66
64.53
0.02
217


10 -
Table 2.2. Description of soybean reproductive-stages (Fehr and
Caviness 1977).
Stage Stage Title
Description
R1 Beginning Bloom
One open flower at any node on the
main stem.
R2 Full Bloom
Open flower at one of the two
uppermost nodes on the main stem with
a fully developed leaf.
R3 Beginning Pod
Pod 5 mm long at one of the four
uppermost nodes on the main stem with
a fully developed leaf.
R4 Full Pod
Pod 2 cm long at one of the four
uppermost nodes on the main stem with
a fully developed leaf.
R5 Beginning Seed
Seed 3 mm long in a pod at one of the
four uppermost nodes on the main stem
with a fully developed leaf.
R6 Full Seed
Pod containing a green seed that fills
the pod cavity at one of the four
uppermost nodes on the main stem with
a fully developed leaf.
R7 Beginning Maturity
One normal pod on the main stem that
has reached its mature pod color.
Mature pod color varies with variety.
R8 Full Maturity
Ninety-five percent of the pods that
have reached their mature pod color.
Five to ten days of drying weather are
required after R8 before the soybeans
have less than 15% moisture, and can
be harvested.


153 -
populations. In the past, numerous researchers have attempted
unsuccessfully to establish such a relationship.


131
Figure 6.1. Flow diagram of a model of VBC adult and egg populations in
a soybean field. See the text for an interpretation of
this diagram.


- 288 -
Gardiner, F. T. (ed.). 1968. Electro-optics handbook, a compendium of
useful information and technical data. Radio Corporation of
America, Commercial Engineering, Harrison, NJ.
Garner, W. W. and Allard, H. A. 1930. Photoperidic responses of
soybeans in relation to temperature and other environmental
factors. J. Agr. Res, 41: 719-735.
Genung, W. G. and V. E. Green, Jr. 1962. Insects attacking
soybeans with emphasis on varietal susceptibility. Proc. Soil Crop
Sci. Soc. Fla. 22: 138-142.
Gilbert, L. E. 1975. Ecological consequences of a coevolved mutualism
between butterflies and plants, pp. 210-240. In L. E. Gilbert and
P. Raven, eds. Coevolution of Animals and Plants. Univ. Texas
Press, Austin, TX.
Goss, G. J. 1979. The interaction between moths and plants containing
pyrrolizidine alkaloids. Environ. Entomol. 8(3): 487-493.
Gould, F. 1984. Role of behavior in the evolution of insect adaptation
to insecticides and resistant host plants. Bull. Entomol. Soc. Am.
30(4): 34-41.
Greene, G. L. 1976. Pest management of the velvetbean caterpillar in
a soybean ecosystem, pp. 602-610. In Proc. World Soybean Res.
Conf., Champaign, IL.
Greene, G. L., J. C. Reid, V. N. Blount, and T. C. Riddle. 1973.
Hating and oviposition behavior of the velvetbean caterpillar in
soybeans. Environ. Entomol. 2(6): 1113-1115.
Gundlach, J. 1881. Contribucin a la entomologa Cubana. G. Montiel,
Havana, Cuba.
Gutierrez, B. and J. Pulido F. 1978. Ciclo de vida y hbitos de
Anticarsia gemmatalis plaga de la soya en el Valle del Cauca.
Revista Colombiana de Entomolgia 4(1 and 2): 3-9.
Hammond, L. C., C. A. Black, and A. G. Norman. 1951. Nutrient
uptake by soybeans on two Iowa soils. Iowa Agrie. Exp. Sta. Res.
Bull. 384: 461-512.
Hampson, G. F. 1913. Catalogue of the Noctuidae in the collection of
the British Museum. Catalogue of the Phalaenae 13: 76-105.
Hanway, J. J. and C. R. Weber. 1971. N, P, and K percentages in
soybean [Glycine max (L.)] plant parts. Agron. J. 63: 286-290.
Heath, R. R., J. H. Tumlinson, N. C. Leppla, J. R. McLaughlin, B.
Dueben, E. Dundulis, and R. H. Guy. 1983. Identification of a sex
pheromone produced by female velvetbean caterpillar moth. J.
Chemical Ecology 9(5): 645-656.


7
Tribe: Phaseoleae
Subtribe: Glycininae
Introduced into the United States as early as 1804, this legume did not
become an important crop in this country until about 1890 (Morse 1927).
Soybean currently is distributed worldwide (Weiss 1983).
General Description
Soybean is a summer annual, usually bushy and upright, and 30-122
cm in height (McGregor 1976, Weiss 1983). The main stem has 14-26
nodes; however, the first 2 nodes actually are composed of 2 opposite
nodes. Two cotyledons are borne at the first node, whereas the second
node bears two primary leaves. All other nodes on the main and lateral
stems bear alternate and pinnate trifoliolates on long petioles;
however, some multi-foliolate lines do occur (Shibles et al. 1975).
Pubescence occurs on most of the above-ground plant surface and may act
as a resistance mechanism to insect oviposition or feeding (see
Kobayashi and Tamura 1939, Nishijima 1960, Kogan 1975, Turnipseed 1977,
Oliveira 1981).
"The root system is extensive, with a tap-root which may exceed 1.5
m in length, giving rise to many lateral branches usually in the 0-30 cm
horizon. However, there is considerable variation between cultivars in
respect of rate of growth, total amount, spread and degree of
penetration of roots. Roots initially elongate faster than above-ground
growth, and in the field under normal conditions, roots of rain-growth
plants will be twice as long as above-ground plant height at the
six-node stage" (Weiss 1983, p. 344). Root nodules occur due to
symbiosis with a nitrogen fixing bacterium, Bradyrhizobium japonicum


- 298 -
I plan to return to Gainesville as a grey-haired alumnus at least once a
year and lay a wreath on the tomb of the unknown graduate student. My
typist is going to love this biographical sketch, as I hope you did.


Table C.8 (continued)
_ a
Date
(D-M-Y)
Hour**
Male0
Agg
Male4*
OAgg
Male*
All
Female1
Adult**
MFAh
Agg
MFA1
OAgg
Time
31-A-82
10
0
2
2
2
0
4
4
60
04-S-82
10
0
0
0
0
0
0
0
51
07-S-82
10
0
0
0
0
0
0
0
59
ll-S-82
10
0
0
0
0
0
0
0
59
14-S-82
10
0
0
0
0
0
0
0
60
18-S-82
10
0
1
1
2
0
3
3
60
21-S-82
10
0
0
0
0
0
0
0
58
25-S-82
10
0
1
1
0
0
1
1
53
02-0-82
10
0
0
0
1
0
l
1
40
05-0-82
10
0
1
1
0
0
1
1
31
09-0-82
10
0
0
0
0
0
0
0
7
04-A-81
11
0
0
0
0
0
0
0
30
07-A-81
11
0
0
0
0
0
0
0
35
11-A-8I
1 1
0
0
0
0
0
0
0
40
14-A-8I
11
0
0
0
0
0
0
0
45
I6-A-81
1 1
0
1
1
0
0
1
l
48
I8-A-8I
1 1
0
0
0
0
0
0
0
51
21-A-8I
1 1
0
0
0
0
0
0
0
56
25-A-81
1 1
0
0
0
0
0
0
0
60
Weight
3
Weight
4
Weight
5
Weight*4 Weight1
1 2
Weight** Weight4*
6 7
0.000000
0.033333
0.033333
0.033333
0.000000
0.066667
0.066667
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.016667
0.016667
0.033333
0.000000
0.050000
0.050000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.018868
0.018668
0.000000
0.000000
0.018868
0.018868
0.000000
0.000000
0.000000
0.025000
0.000000
0.025000
0.025000
0.000000
0.032258
0.032258
0.000000
0.000000
0.032258
0.032258
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.020833
0.020833
0.000000
0.000000
0.020833
0.020833
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
191


Figure 3.9. Orbweaver spider (Acanthepeira sp.) preying on an adult female velvetbean caterpillar.
Photograph was made at the edge of a 1 ha soybean field at the Green Acres Research
Farm, Alachua County, FL, 15 September 1983.


- 242
Egg Shape: Top View
.. Circular.
Side View
.. Dome like or half a circle.
Ridge Number:
x SD = 2.81 2.3, range 21-32, n =
22.
Ridge Morphology:
Distinct, easy to count.
Micropylar Area:
Flat and circular. Sometimes a series
of small circles can be seen.
Spatial Occurrence:
Eggs laid singly.
Similar Eggs and Differences:
M. latipes
.. Large reddish brown splotches,
micropylar area is larger and not as
defined, egg looks circular from side
view.
P. scabra
,. About half the number of ridges.
Ridges protrude well above egg surface


Table 2.4 (continued)
Family Scientific Name
Common Name
Reference
Leguminosae
Stizolobium deeringianum Bort.
Velvetbean
Chittenden (1905)
Tephrosia sp.

USDA (1954b)
Vigna luteola Jacq.
Vigna
Buschman et al. (1977)
Vigna repens (L.) Kuntze
Cowpea
DPIb
Vigna sinensis (L.) Endl.
Cowpea
Hinds and Osterberger (1931)
Begoniaceae
Begonia sp.
Begonia
DPIb
Gramineae
Oryza sativa L.
Rice
Tarrago et al. (1977)
Triticum sp.
Wheat
Wille (1939)
Malvaceae
Gossypium herbaceum L.
Cotton
Douglas (1930)
Hibiscus esculentus L.
Okra
Todd (unpublished)*^


Table C.8 (continued)
Date3
(D-M-Y)
ii **
Hour
Ma leC
Agg
Male^
OAgg
Male*
All
Female^
Adult8
MFAh
*88
MFA1
OAgg
Tlmel
Weight**
1
Weight *
2
Weight
3
Weight"
4
Weight0
5
Weight*5
6
Weight**
7
08-S-81
12
0
0
0
0
0
0
0
25
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
15-S-81
12
0
0
0
0
0
0
0
38
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
aD-M-Y Day, Month, Year; A August, S September, 0 October; 80 1980, 81 1981, 82 1982.
^Hour after sunset.
CMale Agg number of maleq feeding In aggregations. Total number of observed males was 159.
^Male OAgg number of males feeding that are not In aggregations. Total number of observed males was 108.
CMale All =* number of males feeding all males. Total number of observed males was 267.
^Female number of females feeding. Total number of observed females was 128.
^Adult number of adults feeding. Adults were not sexually Identified during the observations. Total number of observed adults was 53.
MFA Agg number of males (all males), females, and adults feeding. Total number of observations was 448.
MFA OAgg 3 number of observations of males (not In aggregations), females, and adults feeding. Total number of observations was 289.
^Tlme total observation minutes were 5865.0.
Ic
Weight 1 (Mnleagg/Mlnute)
193


- 57 -
At 2230 on 19 September 1981, all flight and oviposition stopped
when the temperature fell to 11.9C. Twelve females were picked-up or
touched and none were able to fly. Most remained very rigid and did not
move, but a few flapped their wings once or twice, or took a few steps.
Evidently, 11.9C is near the lower threshold for oviposition. Overall,
these observations indicate that temperature affects egg dispersion and
deposition.
Greene et al. (1973) found that ovipositional activity increased
with decreasing temperature. Neither my results nor those of Moscardi
et al. (1981c) agree with the findings of Greene et al. (1973).
Moscardi et al. (1981c) found that mean total oviposition varied
significantly with temperature (Table 3.3). In a linear regression of
their data and the assumed ovipositional threshold of 11.9C* (see Fig.
3.3), a correlation (r2 = .75, n = 74) was found between total
oviposition per female and temperature with the model:
y = -694.97 + 58.40(x),
where y = total oviposition per female, and
x = temperature between 11.9 and 26.7C.
Slope and intercept parameters were determined with observations and not
mean estimates, but mean estimates are shown in Fig. 3.3 for ease of
view. The regression line was forced through the x intercept at 11.9C.
No other weather factors besides photophase and temperature were
observed visually to affect oviposition (i.e., humidity, rainfall,
moonlight, wind speed and wind direction). Greene et al. (1973) found
*Data used in the regression are listed in Appendix C, Table C.7. Data
of Moscardi et al. (1981c) were stored on computer cards in Building
175, Insect Population Dynamics Laboratory, at the University of
Florida, Gainesville, FL, at the time that this regression model
calculated.
was


To My Friends


112
predict the number of adults in the field, given BLT catch. The number
of adults in the field, as predicted by this equation, could be modified
with mechanistic equations that describe the impact of environmental
variables on adult capture in a blacklight trap. These mechanistic
equations would exert their influence on the parametric coefficients of
the regression equation. Overall, data that were critical to the
construction of a model of adult and egg numbers of VBC were obtained
(see Chapter VI): adult female density, female reproductive potential,
and a calibration equation to convert BLT catch into field densities.
Model completion required only one more piece of information, egg
density data (see Chapter V).


Figure 3.6. Adult velvetbean caterpillar feeding at the surface of a
bahiagrass raceme. Photograph was made at the edge of a 1
ha soybean field on the Green Acres Research Farm, Alachua
County, FL, 16 September 1985.


114
movement into soybean by quantifying adult and egg densities should
provide better insight into the management of this pest.
Movement of VBC adults in a soybean field will be examined with a
model of adult and egg populations in Chapter VI. Adult and egg density
data were required for model construction. Adult density data are
reported in Chapter IV and the present study is a report of egg density
data.
Determination of egg density demanded the resolution of several
methodological problems. First, confusion existed in the literature on
the physical appearance of VBC eggs, particularly egg color (see Watson
1916a, Douglas 1930, Hinds 1930, Ellisor 1942, Greene et al. 1973,
Gutierrez and Pulido 1978). Second, little was known about Lepidoptera
eggs found on soybean plants (see Herzog and Todd 1980). Third,
conflicting reports existed as to whether VBC eggs could be sampled (see
Greene et al. 1973, Ferreira and Panizzi 1978). Lastly, egg and adult
densities needed to be assessed simultaneously to describe the
relationship between the two life stages, a formidable problem (see
Oloumi-Sadeghi et al. 1975, Lopez et al. 1979, Buntin 1980, Hogg and
Gutierrez 1980, Pedgley and Betts 1980).
Materials and Methods
Egg Development and Coloration
From 1980-84, VBC eggs from colony and wild adults were examined to
determine their developmental times and coloration. Colony females were
used in all years, except for wild females in 1983. Wild females were
collected on 27 September 1983 with an aerial net in a 10 ha soybean
field (cv. USV1) in Alachua County, FL. All females were maintained at
26.7 1C,


Table 4.1. Description of physical variables monitored in Alachua County, FL, in 1981-82.
Physical
Variable
Monitoring Device
or Source
Site3
Location
Frequency
of Reading
Yearb
Monitored
Temperature (C)
Hygrothermograph, Weather
Measure Corp., Model H311
Edge (Ambient)
and Field
Continuous
81,82
Temperature (C)
Esterline AngusR PD2064
Microprocessor
Edge (Ambient)
Continuous
81,82
Relative Humidity (%)
Hygrothermograph, Weather
Measure Corp., Model H311
Edge (Ambient)
and Field
1 h
81,82
Rainfall (cm)
Universal Recording Rain
Gauge, Belfort Instr. Co.,
12" chart with dual springs
Edge
Continuous
81,82
Wind Speed (m/sec)
Gill, 3-cup Anemometer,
R. M. Young Co., Model
12102
Edge, 6.4 m
Height
15 min
81
Wind Direction0
Gill Microvane, R. M.
Young Co., Model 12302
Edge, 6.4 m
Height
15 min
81
Barometric Pressure
(MB)
Mirobarograph, Weather
Measure Corp., Model B211
Edge (Ambient)
Continuous
81,82
Sunset and Sunrise
Times, Length of Day
and Night
Oliverd
Alachua County,
FL
24 h
80,81,82


14 -
Velvetbean Caterpillar Ecology
Anticarsia gemmatalis Hubner was described by Hubner (1816, cited
by Ford et al. 1975). Kimball (1965) and Borror et al. (1981) provide
part of the hierarchial classification for this insect as follows:
Order: Lepidoptera
Suborder: Ditrysia
Superfamily: Noctuoidea
Family: Noctuidae
Subfamily: Erebiinae.
Seven synonyms for gemmatalis are listed by Schaus (1940). The
common name for A^_ gemmatalis, as accepted by the Entomological Society
of America, is the velvetbean caterpillar (Sutherland 1978). Severe
defoliation of velvetbean (Stizolobium deeringianum Bort.) by this
insect in the early 1900's resulted in its common name (Chittenden 1905,
Watson 1916a).
Distribution
The VBC is a tropical to subtropical species of the Western
Hemisphere (Ford et al. 1975) and ranges over much of North and South
America, and all of Central America and the West Indies. In North
America, the northern limits of the range are slightly above the 45N
parallel, extending into Ontario and Quebec, Canada. In South America,
the southern limit of the range appears to be approximately the 35S
parallel, extending to Buenos Aires, Argentina (Ford et al. 1975, Herzog
and Todd 1980).
The range of VBC in North America fluctuates temporally due to (1)
suspected migration of adults (Watson 1916a), (2) winter mortality of
immature stages (Buschman et al. 1981a), and (3) lack of occurrence of
immature stages (Ellisor 1942, Buschman et al. 1977, Waddill et al.


253 -
Figure E.3 (continued)


105
distinctly biased toward females, and is significantly different from
the other sex ratio values (see Table 4.4). Why this sex ratio is so
low and biased toward females is unknown, but perhaps females prefer to
reside in soybean while males prefer other sites.
Impact of Physical Variables
Select physical variables were regressed against BLT catch
(1981-82) of females, males, and adults (females and males). Regression
results with total BLT numbers are shown in Table 4.5. The parametric
coefficient of flight temperature was significant in all of the models,
except for females in 1982 (see Table D.6 for an explanation of flight
temperature). The parametric coefficient of vapor pressure deficit was
significant in three of the models, while the parametric coefficient of
moonlight intensity was the only other coefficient to show significance.
The effects of flight temperature and vapor pressure deficit on adult
catch are understandable, as temperature (see Chapter III) and VPD (see
Leppla 1976) affect VBC dynamics. The effect of moonlight intensity was
unexpected as field observations (see Chapter III) had not disclosed
such an affect; however, moonlight is known to affect the flight of many
moths (see Nemec 1971, Bowden and Church 1973, Douthwaite 1978). Values
of r2 were much higher in 1981 than in 1982, but a large amount of
variation in BLT response for both years was not explained.
Regression models for weighted BLT numbers are shown in Table 4.6.
The predictive capabilities of these models are very poor, as reflected
in their extremely low r2 values. Low r2 values for both total and
weighted BLT models demonstrate that the proportion of total variation
in the BLT responses, explained by the physical variables, is extremely
low in most cases. Unknown and/or non-monitored environmental variables
affected adult capture. Adult number may have varied due to area-wide


180 -
Table C.5 (continued)
Number of
Date3
(D-M-Y)
Hour After
Sunset
Observations
of Oviposition
c
Observational
Time (min)
Weighted^
Observations
03-S-82
5
0
11
0.000000
04-S-82
5
1
19
0.052632
10-S-82
5
0
19
0.000000
24-S-82
5
0
37
0.000000
25-S-82
5
0
18
0.000000
23-A-81
6
0
42
0.000000
13-S-81
6
0
44
0.000000
04-S-82
6
1
60
0.016667
25-S-82
6
3
60
0.050000
13-S-81
7
0
21
0.000000
04-S-82
7
0
11
0.000000
25-S-82
7
0
3
0.000000
13-S-81
8
0
39
0.000000
25-S-81
8
0
33
0.000000
13-S-81
9
0
60
0.000000
24-A-82
9
0
32
0.000000
28-A-82
9
0
27
0.000000
31-A-82
9
0
24
0.000000
04-S-82
9
0
19
0.000000
07-S-82
9
0
1
0.000000
ll-S-82
9
0
11
0.000000
14-S-82
9
0
7
0.000000
18-S-82
9
0
2
0.000000
25-S-82
9
0
52
0.000000
21-A-81
10
0
20
0.000000
25-A-81
10
0
16
0.000000
28-A-81
10
0
13
0.000000
01-S-81
10
0
8
0.000000


PAGE
V MEASUREMENT OF EGG DENSITY 113
Introduction 113
Materials and Methods 114
Egg Development and Coloration 114
Field Sampling of Velvetbean Caterpillar Eggs 115
Results and Discussion 116
Egg Development and Coloration 116
Field Sampling of Velvetbean Caterpillar Eggs 122
Egg-Speckling Hypothesis 124
Conclusions 126
VI A MODEL OF VELVETBEAN CATERPILLAR ADULT
AND EGG POPULATIONS 127
Introduction 127
Model Objective 128
Data Requirements for Model Construction
and Validation 128
Model Assumptions 130
Model Conceptualization 130
Model Structure 132
Function for Total Female Population 133
Functions for Mated Female Population and Mortality 133
Functions for Oviposition 134
Function for Total Egg Number 136
Function for Predicted Egg Density.. 136
Model Behavior 136
Simulation of 1982 Egg Population with a Constant
Ovipostional Rate 137
Simulation of 1982 Egg Population with a Variable
Ovipositional Rate 137
Simulation of 1981 Egg Population with a Variable
Ovipositional Rate 142
Conclusions 144
- xi -


- 245 -
Figure E.l (continued)


Carlysle, Niki Altieri, Nell Backus, Niklaus Hostettler, Joe DeNicola,
Arlene Arroya, Lois Wood, Nancy Osteen, Sanjoy Malik, Nancy Cohen, Carol
Morris and Tasha, Sue Rutherford, John Knaub, Edilson Oliveira,
Euripedes Meneze, Jorge Pena, Wade Bell, Eunice Smith, Gary Fritz, Doug
Johnson, Mike Linker, John Luna, Vicki Ferguson, Bonnie Busick, Sherry
Hickman, Leslie Daniels, Kirti Patel, Steve Hurst, Susan Jungreis,
Rudiger Klein, Jackie Belwood, Howard Beck, Phil Callahan, Ngo Dong,
Annie Yao, E. B. Whitty, Dennis Profant, Rick Reynolds, Bob Sullivan,
Pamela A. Duelly (and plant #44), Edna Mitchell, Susan Braxton, Takuja
Hayakawa, David Hall, Sheila Eldridge, Myrna Lynchfield, Barbara and
Keith Hollien, Ralph Brown, Jack Rye, Richard Guy, Polly Teal, Sue
Wineriter, Tommy Smith, T. J. Walker, Frank Mead, Marsha Stanton, G. B.
Edwards, David W. Hall, Paul, Gene, Rudy, Anne, Weboon and Kent.
The completion of my dissertation would have been impossible
without the friendship of Gail Childs (and Meghan), Greg Wheeler (my
drinking buddy), Larry (Skep) Smith, Mike Keller, Cherie Warlick and
Barbara Muschlitz. Each of them has a very special place in my heart.
Also, the completion of my dissertation would have been impossible
without the love of my family and their many sacrifices. I have
frequently missed the love and companionship of Nancy, Ben Sr., Buddy,
Barbara, Scott, Kathy, Caroline, Susan, Roy, Helen, and Ollie.
- viii


CHAPTER IV
MEASUREMENT AND ANALYSIS OF INTRAFIELD
ACTIVITY OF ADULT VELVETBEAN CATERPILLAR
Introduction
The velvetbean caterpillar (VBC) is believed to "overwinter" in
much of the Caribbean Basin and South America and is conjectured to move
annually into the southern United States (Watson 1916a, Herzog and Todd
1980, Buschman et al. 1981a). The magnitude and timing of VBC
immigration are unknown, as no direct evidence exists (Buschman et al.
1981a). Based on density data of larvae, adult VBC evidently invade
soybean in northern Florida during late June, July and August (see
Greene 1976, Menke and Greene 1976, Linker 1980). Following adult
colonization, larvae reach peak densities in August September and,
occasionally, early October (Greene 1976, Menke and Greene 1976, Linker
1980). With the October onset of soybean senescence, VBC adults are
suspected to move onto alternate hosts where their larvae have been
collected (Ellisor 1942, Greene 1976, Buschman et al. 1981a). Larvae
and pupae appear incapable of overwintering in northern Florida
(Buschman et al. 1977); thus, infestation of soybean the following year
depends on VBC adult immigration (see Watson 1916a, Buschman et al.
1977, 1981a).
Current management of VBC is directed at control of in-field larval
densities (Linker 1980). This type of management treats the symptoms of
the pest problem and not the cause (see Stimac and Barfield 1979,
Barfield and O'Neil 1984). In a simulation model of soybean/VBC
81


PAGE
Figure 6.4. Mean velvetbean caterpillar egg density per
.91 m-row of soybean during 1981 in a 1 ha
field at the Green Acres Research Farm, Alachua
County, FL. Ovipositional rate was variable
during the simulation
143
xviii


NUMBER OF FEMALES/REPRODUCTIVE CATEGORY
- 93 -
Figure 4.3. Total number of adult velvetbean caterpillar females per
reproductive category per night. Categories are (1)
unmated, no spermatophore, (2) mated, fat body content full
to 1/3 depleted, (3) mated, fat body content 1/3 to 2/3
depleted, and (4) mated, fat body content 2/3 or more
depleted. Females were caught in a blacklight trap during
1981 at the Green Acres Research Farm, Alachua County, FL.


- 99 -
the BLT prior to canopy closure. From dates 190-216, 121 adults were
caught in the BLT (see Fig. 4.2 and Appendix D, Table D.3). Based on
BLT and trap-cage data, and on behavioral observations (see Chapter
III), adults moved into the field at night but did not stay in the field
during the day until the canopy began to close. Also, females laid
eggs* in the field prior to being captured in the trap-cage. Adults may
take-up "residence" in the field at canopy closure due to changes in
atmospheric humidity or vapor pressure deficit.
Effect of Vapor Pressure Deficit
In 1981-82, ambient** vapor pressure deficit (VPD) was higher
during the day [see Figs. 4.7(A) and 4.8(A)], Field** VPD was high
during the day until the canopy closed ca. 30 July '81 (date 211) and 27
July '82 (date 208)[see Figs. 4.7(B) and 4.8(B)], In 1981, field VPD
during the day fell below 5 mm Hg consistently after date 210 [see Fig.
4.7(B)], Adults were first observed in the field on date 215. In 1982,
field VPD during the day fell consistently below 5 mm Hg after date 207
[see Fig. 4.8(B)], Adults were first observed in the field on date 214
and first captured in the trap-cage on date 217. In 1981 and 1982,
adults moved into the field after the VPD had fallen below 5 mm Hg.
Late in the field season of 1982, as the soybean began to senesce
and the VPD rose above 5 mm Hg, adults continued to be caught in the
trap-cage. The reason for the continued presence of adults in soybean
at this time is unclear but may have been due to physiological changes
*Eggs were first collected in samples on 5 July 1982, or date 186 (see
Chapter V).
**Ambient and field VPD (day and night) are mean values based on
readings of temperature and humidity that were recorded at 1 h
intervals. See Appendix D, Table D.6, for formula used to calculate
VPD.


Table A.1 (continued)
Cultivation
Irrigation
Harvest Date
Seed Moisture
Yield (kg/ha)
July 9, Sweeps
June 4, 5 cm
(%)
October 17
10.7
901.1
July 13, Sweeps
July 14, Rolling
July 23, Rolling
July 21, Rolling
June 12, 5 cm
June 9, 1.3 cm
July 29, 5 cm
October 14
October 22
13
10.7
1303.6
2030.3
156


175 -
Table C.3 (continued)
Number of
Date3
(D-M-Y)
Hour After
Sunset
Observations
of Mating
c
Observational
Time (min)
Weighted^
Observations
28-A-82
9
0
27
0.000000
31-A-82
9
0
24
0.000000
04-S-82
9
0
19
0.000000
07-S-82
9
0
1
0.000000
ll-S-82
9
0
11
0.000000
14-S-82
9
0
7
0.000000
18-S-82
9
0
2
0.000000
25-S-82
9
1
52
0.019231
16-A-81
10
0
45
0.000000
18-A-81
10
0
23
0.000000
21-A-81
10
0
20
0.000000
25-A-81
10
0
16
0.000000
28-A-81
10
0
13
0.000000
Ol-S-81
10
0
8
0.000000
04-S-81
10
0
4
0.000000
13-S-81
10
0
60
0.000000
28-A-82
10
0
53
0.000000
31-A-82
10
1
60
0.016667
04-S-82
10
0
51
0.000000
07-S-82
10
0
59
0.000000
ll-S-82
10
0
59
0.000000
14-S-82
10
0
60
0.000000
18-S-82
10
0
60
0.000000
21-S-82
10
0
58
0.000000
25-S-82
10
0
53
0.000000
16-A-81
11
0
48
0.000000
18-A-81
11
0
51
0.000000
21-A-81
11
0
56
0.000000
25-A-81
11
0
60
0.000000


"Any glimpse into the life of an animal
quickens our own and makes it so much
the larger and better ever way."
John Muir, 1880


259
260
261
262
263
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265
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268
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285
286
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- 284 -
(continued)
FBLT
LB05
EEGG
UB05
SOY
39
16
31
4.32
9.76
15.20
16
39


16
29


16
24
10.96
23.34
35.72
16
27
16
28


16
15


16
13
5.67
9.76
13.85
17
38


17
46


17
3
4.52
10.19
15.85
17
10


17
35


17
57

17
60
3.49
7.22
10.94
18
23



18
23



18
26
0.61
8.49
16.37
18
43



18
24



18
13



18
12
0.00
0.85
2.01
18
14



18
20



18
16
0.26
1.70
3.14
19
17


19
54


19
18

19
26
0.00
0.00
0.00
20


A MODEL OF ADULT AND EGG POPULATIONS
OF Anticarsia gemmatalis Hubner
(LEPIDOPTERA: NOCTUIDAE) IN SOYBEAN
By
BEN GREGORY, JR.
A DISSERTATION PRESENTED TO THE GRADUATE SCHOOL
OF THE UNIVERSITY OF FLORIDA IN
PARTIAL FULFILLMENT OF THE REQUIREMENTS
FOR THE DEGREE OF DOCTOR OF PHILOSOPHY
UNIVERSITY OF FLORIDA
1986

Copyright 1986
by
Ben Gregory, Jr

To My Friends

"Any glimpse into the life of an animal
quickens our own and makes it so much
the larger and better ever way."
John Muir, 1880

ACKNOWLEDGEMENTS
The inadequacy of words will inhibit me from being able to express
completely my feelings of gratitude for all of the help that I received
during my Ph.D. program, particularly with regards to my major professor
and friend, Carl Barfield. He constantly provided me with funds and
equipment for my research and always had time to encourage my endeavors
and listen to my ideas. I learned much about myself from working with
Carl and I will always be indebted to him for the opportunities he
provided me and for the scientific development I achieved under his
aegis. I admire Carl for what he has achieved as a scientist and as a
father and I will miss his sense of humor. I cannot write enough about
him. Working with Jerry Stimac, a member of my committee, has been a
very rewarding experience. His ecological insights and systems
perspectives have deeply affected my development as a scientist. Jerry
is a free thinker and an individual that loves to explore his
environment. He also has an insatiable and wonderful penchant for a
good laugh. Frank Slansky, another member of my committee, exhibits
scientific standards that I would one day like to achieve. Frank is a
remarkable scientist and I am indebted to him for his ecological
insights into my experiments. He has a fantastic sense of humor and he
never seems to miss a beat with it. He also has a wonderful family.
Interacting with Ken Boote, the last member of my committee, has been
very educational. His inquiries about my course work and research
v

progress were always helpful and encouraging. Ken's boundless energy
and enthusiasm have been enjoyed and admired.
I owe special thanks to Don Herzog. Without his financial support
and friendship my program would have been very difficult to complete, if
not impossible. His constant support and encouragement over the years
have always been appreciated. I envy anyone that has the opportunity to
work and interact with Don.
I also owe special thanks to Strat Kerr for the tireless hours he
spent coordinating my graduate activities and for financially supporting
me during some rough times. He constantly went out of his way for me
and liberally interpreted bureaucratic rules that made life a lot easier
for me. The students in the department are lucky to have Strat's
guidance, help and concern.
I would like to thank Norm Leppla for providing me with laboratory-
reared velvetbean caterpillar larvae over the years. Our many
discussions about science, life and women (not necessarily in that
order) have been illuminating. Norm is a good friend.
Pat Greany has a wonderful personality and I am indebted to him for
his photographic expertise. I learned a lot from Pat and I appreciate
the many hours he took to help me with my research.
I thank Everett Mitchell for loaning me his blacklight traps.
Everett's field knowledge was invaluable for the success of my project
and he always had time to listen to my ideas and to help me with their
fruition.
I will miss the frequent discussions I had with Jon Allen. He
constantly stimulated my thoughts about quantitative ecology and taught
me how to convert complex problems into easy problems that could be
readily solved. His views about life have been illuminating.
- vi -

Discussions about personal and career goals with Dale Habeck, John
Strayer, Don Hall, Jim Lloyd, and Dan Shankland were invaluable.
I thank Jim Jones for suggesting that I write my model with SAS and
I am indebted to Ramon Littel, Ken Portier, Mark Yang, Victor Chew,
Partha Lahiri, and Greg Pepples for their statistical expertise. I also
owe thanks to Niklaus Hostettler and the legions of CIRCA consultants
that helped me with my SAS programs.
I owe very special thanks to Anne Keene for typing my dissertation
and for her enduring abilities to type both night and day. The
completion of my dissertation would have been impossible without her
assistance. She is a superb typist and frequently went out of her way
to accommodate my schedule. She loves hard work and will not stop until
the job is done. Anne has a real zest for life and is a very special
person. The world needs more people like Anne.
Margie Niblack drew most of the figures in my dissertation, as well
as my M.S. thesis. Working with her has always been fun. Margie is an
excellent artist/illustrator, works very hard, and is seemingly
tireless. Her willingness to help me with my graphics whenever possible
will always be appreciated. I will miss her warm personality, sweet-
naturedness and generous heart.
I would like to thank Laura Line Reep for drawing three of the
figures in my dissertation. Mary Crume of the Graduate School completed
a mechanical critique of my dissertation. The time and effort she spent
completing her excellent critique have been appreciated very much.
In far too many ways to mention, my work and life have been
enriched by the friendship and help of Paul Wales, Kris Elvin, Bob
O'Neil et al., Jane and Ken Cundiff, Debi Waters, Nancy Phillips, Carol
- vii

Carlysle, Niki Altieri, Nell Backus, Niklaus Hostettler, Joe DeNicola,
Arlene Arroya, Lois Wood, Nancy Osteen, Sanjoy Malik, Nancy Cohen, Carol
Morris and Tasha, Sue Rutherford, John Knaub, Edilson Oliveira,
Euripedes Meneze, Jorge Pena, Wade Bell, Eunice Smith, Gary Fritz, Doug
Johnson, Mike Linker, John Luna, Vicki Ferguson, Bonnie Busick, Sherry
Hickman, Leslie Daniels, Kirti Patel, Steve Hurst, Susan Jungreis,
Rudiger Klein, Jackie Belwood, Howard Beck, Phil Callahan, Ngo Dong,
Annie Yao, E. B. Whitty, Dennis Profant, Rick Reynolds, Bob Sullivan,
Pamela A. Duelly (and plant #44), Edna Mitchell, Susan Braxton, Takuja
Hayakawa, David Hall, Sheila Eldridge, Myrna Lynchfield, Barbara and
Keith Hollien, Ralph Brown, Jack Rye, Richard Guy, Polly Teal, Sue
Wineriter, Tommy Smith, T. J. Walker, Frank Mead, Marsha Stanton, G. B.
Edwards, David W. Hall, Paul, Gene, Rudy, Anne, Weboon and Kent.
The completion of my dissertation would have been impossible
without the friendship of Gail Childs (and Meghan), Greg Wheeler (my
drinking buddy), Larry (Skep) Smith, Mike Keller, Cherie Warlick and
Barbara Muschlitz. Each of them has a very special place in my heart.
Also, the completion of my dissertation would have been impossible
without the love of my family and their many sacrifices. I have
frequently missed the love and companionship of Nancy, Ben Sr., Buddy,
Barbara, Scott, Kathy, Caroline, Susan, Roy, Helen, and Ollie.
- viii

TABLE OF CONTENTS
PAGE
ACKNOWLEDGEMENT S v
LIST OF TABLES xiii
LIST OF FIGURES xvi
ABSTRACT xix
CHAPTERS
I INTRODUCTION 1
II LITERATURE REVIEW 6
Introduction 6
Soybean Ecology 6
General Description 7
Development and Growth 8
Water Stress 13
Susceptibility to Insect Attack 13
Velvetbean Caterpillar Ecology 14
Distribution 14
Life Stages 15
Life History 16
Adult Behavior 16
Host Plants 17
Natural Enemies 23
Sampling and Economic Thresholds 23
Models 23
Velvetbean Caterpillar as a Soybean Pest 24
Velvetbean Caterpillar/Soybean Interactions 25
III BEHAVIORAL ECOLOGY OF ADULT VELVETBEAN CATERPILLAR 28
Introduction 28
- ix -

PAGE
Literature Review 29
General Activity 29
Flight in the Laboratory 29
Flight in the Field 30
Mating 32
Oviposition 34
Feeding 37
Predators 38
Research Goals 38
Materials and Methods 39
Quantitative Technique 40
Assumptions 41
Results and Discussion 41
Flight Activity 43
Mating 45
Oviposition 53
Feeding 61
Predators 74
Conclusions 77
IV MEASUREMENT AND ANALYSIS OF INTRAFIELD ACTIVITY
OF ADULT VELVETBEAN CATERPILLAR 81
Introduction 81
Materials and Methods 82
Adult Sampling 82
Female Dissections 85
Physical Variables 85
Results and Discussions 88
Blacklight Trap 88
Female Dissections 90
Adult Trap-Cage 95
Effect of Vapor Pressure Deficit 99
Sex Ratio 102
Impact of Physical Variables 105
Calibration of Adult Density 108
Conclusions 108
x

PAGE
V MEASUREMENT OF EGG DENSITY 113
Introduction 113
Materials and Methods 114
Egg Development and Coloration 114
Field Sampling of Velvetbean Caterpillar Eggs 115
Results and Discussion 116
Egg Development and Coloration 116
Field Sampling of Velvetbean Caterpillar Eggs 122
Egg-Speckling Hypothesis 124
Conclusions 126
VI A MODEL OF VELVETBEAN CATERPILLAR ADULT
AND EGG POPULATIONS 127
Introduction 127
Model Objective 128
Data Requirements for Model Construction
and Validation 128
Model Assumptions 130
Model Conceptualization 130
Model Structure 132
Function for Total Female Population 133
Functions for Mated Female Population and Mortality 133
Functions for Oviposition 134
Function for Total Egg Number 136
Function for Predicted Egg Density.. 136
Model Behavior 136
Simulation of 1982 Egg Population with a Constant
Ovipostional Rate 137
Simulation of 1982 Egg Population with a Variable
Ovipositional Rate 137
Simulation of 1981 Egg Population with a Variable
Ovipositional Rate 142
Conclusions 144
- xi -

PAGE
VII SUMMARY AND CONCLUSIONS 147
APPENDICES
A AGRONOMIC PRACTICES AND SOYBEAN PHENOLOGICAL-STAGES 155
B IDENTIFICATION OF ADULT Anticarsia gemmatalis Hubner
and Mocis latipes Guenee 161
C BEHAVIORAL OBSERVATIONS: QUANTITATIVE TECHNIQUE AND DATA.... 168
D ADULT DENSITY AND PHYSICAL VARIABLE DATA, AND
MATHEMATICAL DESCRIPTIONS OF PHYSICAL VARIABLES 203
E PICTORIAL KEY OF SOME LEPIDOPTERA EGGS FOUND ON SOYBEAN 237
F EGG DENSITY DATA 273
G SAS PROGRAMS AND DATA FILES FOR MODEL OF ADULT AND
EGG POPULATIONS 276
LITERATURE CITED 285
BIOGRAPHICAL SKETCH 297
xii -

LIST OF TABLES
PAGE
Table 1.1. Comparison of soybean yield and profit among
various densities and timings of adult
velvetbean caterpillar influx, as simulated
with the Soybean Integrated Crop Management
model. Soybean was not irrigated in any
simulations 4
Table 2.1. Description of soybean vegetative stages 9
Table 2.2. Description of soybean reproductive-stages 10
Table 2.3. Average and range of developmental time
required for a soybean plant to develop between
stages 12
Table 2.4. Reported host plants of larval velvetbean
caterpillar 18
Table 3.1. Amount of time dedicated to behavioral
observation of adult velvetbean caterpillar in
a 1 ha soybean field at the Green Acres Research
Farm, Alachua County, FL, from 1980-82 42
Table 3.2. Estimates of the absolute density of adult
females of the velvetbean caterpillar in a
soybean field. Density was determined with
an adult trap-cage (see Chapter IV) in 1982
at the Green Acres Research Farm, Alachua
County, FL 55
Table 3.3. Mean total oviposition by adult females of the
velvetbean caterpillar reared from eggs at
constant temperatures, 14L:10D photoperiod, and
RH > 80% 58
Table 3.4. Number of unsexed, male, and female adults
of the velvetbean caterpillar observed
feeding in a soybean field at Green Acres
Research Farm, Alachua County, FL, in 1980-82 62
Table 3.5. Observational records of feeding by adult
velvetbean caterpillar during photophase at
the Green Acres Research Farm, Alachua County,
FL, from 1980-83 63
- xiii

PAGE
Table 3.6. Number of unsexed adults of the velvetbean
caterpillar observed feeding in a soybean
field at Green Acres Research Farm, Alachua
County, FL, in 1980-82. Description of food
site and host provided
Table 3.7. Number of male and female adults of the
velvetbean caterpillar feeding in a soybean
field at Green Acres Research Farm, Alachua
County, FL, from 1980-82. Description of food
site and host provided
Table 3.8. Number of adult males of the velvetbean
caterpillar feeding in a soybean field at
Green Acres Research Farm, Alachua County,
FL, from 1980-82. Also, number of males per
aggregate, number of aggregates, and
description of food site are provided
Table 3.9. Records of spider predation on adult velvetbean
caterpillar (VBC) from 1980-83 at Green Acres
Research Farm, Alachua County, FL, in a 1 ha
soybean field. All records occurred during
scotophase
Table 4.1. Description of physical variables monitored
in Alachua County, FL, in 1981-82
Table 4.2. Amount of rainfall recorded at the number 3
WSW climatological station of the University
of Florida, Gainesville, FL, Alachua County.
Cooperative climatological station of the
Agronomy Department and NOAA
Table 4.3. The mean number (SE) of spermatophores per
female per reproductive category of adult
velvetbean caterpillar. Females were caught in
a blacklight trap during 1981 at the Green
Acres Research Farm, Alachua County, FL
Table 4.4. Mean seasonal sex ratios of adult velvetbean
caterpillar caught in blacklight traps and
an adult trap-cage in a 1 ha soybean field
at the Green Acres Research Farm, Alachua
County, FL
Table 4.5. Regression equations of physical variables and
total numbers of males, females, and adults of
the velvetbean caterpillar. Moths were caught
in a blacklight trap at the Green Acres
Research Farm, Alachua County, FL
65
66
67
75
86
91
96
104
106
- xiv -

PAGE
Table 4.6.
Regression equations of physical variables and
weighted numbers of males, females, and adults
of the velvetbean caterpillar. Moths were
caught in a blacklight trap at the Green Acres
Research Farm, Alachua County, FL 107
Table 4.7.
Regression equations of total daily number of
velvetbean caterpillar moths in the field and
total nightly number of moths caught in the
blacklight trap during 1982 at the Green Acres
Research Farm, Alachua County, FL. Total number
of moths (females, males, and total adults) were
determined with adult trap-cage data 109
Table 4.8.
Regression equations of total daily number of
velvetbean caterpillar moths in the field and
total nightly smoothed number of moths caught in
the blacklight trap (BLT) during 1982 at the
Green Acres Research Farm, Alachua County, FL.
Total number of moths (females, males, and total
adults) were determined with adult trap-cage
Table 5.1.
Mean developmental time of speckled, brownish,
and hatched velvetbean caterpillar eggs at two
different temperatures. Colony (1982) and wild
(1983) females were used in the study 119
Table 5.2.
Mean developmental time and rate (SE) for
speckling to occur in VBC eggs from colony
females at six different temperatures. Mean
number of degree-hours required for speckling
(thermal constant) was 153.27 120
Table 5.3.
The total number of degree-hours accumulated
between sunset (onset of oviposition) and
plant sampling during each sample date in 1981
and 1982. Mean number of degree-hours required
for speckling to occur in VBC eggs is 153.27 123
Table 6.1.
Parametric values of ovipositional rate and SOY
used in the oviposition function of the adult
and egg population model of velvetbean caterpillar.
Values are based on data collected in 1982 and
model simulations IBS
xv

LIST OF FIGURES
PAGE
Figure 3.1. Mating pair of adult velvetbean caterpillar
on a soybean leaflet 48
Figure 3.2. The percent-normalized sample mean ( SE) of
each post-sunset hour for activities of adult
velvetbean caterpillars 52
Figure 3.3. Linear relationship between total eggs per
velvetbean caterpillar adult female and
temperature 59
Figure 3.4. Aggregation of velvetbean caterpillar males
on an aerial net 68
Figure 3.5. Aggregation of velvetbean caterpillar males
on the screen of an insectary 69
Figure 3.6. Adult velvetbean caterpillar feeding at the
surface of a bahiagrass raceme 71
Figure 3.7. Adult velvetbean caterpillar feeding at the
surface of a dead soybean leaflet 72
Figure 3.8. Green lynx spider [Peucetia viridans (Hentz)]
preying on an adult male velvetbean caterpillar 78
Figure 3.9. Orbweaver spider (Acanthepeira sp.) preying on
an adult female velvetbean caterpillar 79
Figure 4.1. Trap-cage used to collect adult velvetbean
caterpillar in a 1 ha soybean field during 1982
at the University of Florida's Green Acres
Research Farm, Alachua County, FL 84
Figure 4.2. Total number of velvetbean caterpillar moths
captured in a blacklight trap per night in a
1 ha soybean field at the Green Acres Research
Farm, Alachua County, FL 89
Figure 4.3. Total number of adult velvetbean caterpillar
females per reproductive category per night 93
- xv i -

PAGE
Figure 4.4. Total number of velvetbean caterpillar unmated
adult females per fat body content category
per night 94
Figure 4.5. The mean number of spermatophores per adult
velvetbean caterpillar female per week 97
Figure 4.6. Mean number ( 90% confidence interval) of
velvetbean caterpillar moths captured per
sample (21.16 m2) with the adult trap-cage 98
Figure 4.7. Vapor pressure deficit (VPD) in a 1 ha
soybean field in 1981 at the Green Acres
Research Farm, Alachua County, FL 100
Figure 4.8. Vapor pressure deficit (VPD) in a 1 ha
soybean field in 1982 at the Green Acres
Research Farm, Alachua County, FL 101
Figure 4.9. Sex ratio of velvetbean caterpillar adults
caught in blacklight traps (BLT) and an adult
trap-cage (ATC) in a 1 ha soybean field at the
Green Acres Research Farm, Alachua County, FL 103
Figure 5.1. Eggs of the velvetbean caterpillar 117
Figure 5.2. Developmental rate of speckling in VBC eggs
at six different temperatures 121
Figure 5.3. Mean densities per .91 m-row ( 95% confidence
interval) of freshly-laid VBC eggs on soybean
at the Green Acres Research Farm, Alachua
County, FL 125
Figure 6.1. Flow diagram of a model of VBC adult and egg
populations in a soybean field 131
Figure 6.2. Mean velvetbean caterpillar egg density per
.91 m-row of soybean during 1982 in a 1 ha
field at the Green Acres Research Farm, Alachua
County, FL. Ovipositional rate was a constant
during the simulation 138
Figure 6.3. Mean velvetbean caterpillar egg density per
.91 m-row of soybean during 1982 in a 1 ha
field at the Green Acres Research Farm, Alachua
County, FL. Ovipostional rate was variable
during the simulation 140
- xvii -

PAGE
Figure 6.4. Mean velvetbean caterpillar egg density per
.91 m-row of soybean during 1981 in a 1 ha
field at the Green Acres Research Farm, Alachua
County, FL. Ovipositional rate was variable
during the simulation
143
xviii

Abstract of Dissertation Presented to the Graduate School
of the University of Florida in Partial Fulfillment of the
Requirements for the Degree of Doctor of Philosophy
A MODEL OF ADULT AND EGG POPULATIONS
OF Anticarsia gemmatalis Hubner
(LEPIDOPTERA: NOCTUIDAE) IN SOYBEAN
By
BEN GREGORY, JR.
May, 1986
Chairman: C. S. Barfield
Major Department: Department of Entomology and Nematology
A model of adult and egg populations of the velvetbean caterpillar
(A. gemmatalis) was constructed and validated. The model mimicked
velvetbean caterpillar (VBC) egg densities in a soybean field within 95%
confidence intervals of estimated means. Model construction was based
on data from nine separate experiments (1980-84) that allowed for an
understanding or quantification of the following: adult moth
identification, adult behavior in the field, relative and absolute
estimates of adult density, female reproductive states, egg
identification, egg developmental rates, absolute estimates of egg
density, and the impact of various environmental variables on adult and
egg dynamics.
Adult density estimates were obtained with a blacklight trap and an
unique adult trap-cage. These density estimates were calibrated with a
linear regression equation that was used in the model structure to
- xix

predict the number of ovipositing females in the field. The capture of
adults in the blacklight trap (BLT) coincided with the appearance of
eggs in the field, while adult residency in the field appeared to be
delayed until an appropriate vapor pressure deficit had been reached in
the field. Dissections of adult females revealed that most females
were mated and contained large amounts of fat body. Select physical
variables were explored with multiple linear regression for their effect
on blacklight trap catch but no consistently adequate correlations were
uncovered.
Velvetbean caterpillar eggs were shown to be polychromatic during
development. These color changes were temperature-dependent and were
used to age field collected eggs. Egg densities predicted by the model
were more accurate with a variable ovipositional rate as opposed to a
constant rate. The variable ovipositional rate was linked to changes in
soybean phenology. In model validation, 65% of the model's predicted
values fell within 95% confidence intervals of field estimates.
Differences between predicted and estimated values were attributed to
unpredictable fluctuations in BLT catch and to variation in
ovipositional rate between years.
xx

CHAPTER I
INTRODUCTION
Soybean, Glycine max (L.) Merrill, is presently the most important
grain legume in the world and is used for food, medicine, and oil (Weiss
1983). Farmers in the United States produce ca. 56% of the world's
soybean or ca. 43 million metric tons (FAO 1984). Thirty-seven percent
of the soybean production in the United States occurs in the southeast,
and this percentage is expected to increase considerably by the year
2000 because of an increasing worldwide demand (Turnipseed et al. 1979).
Soybean production in the southeastern United States is plagued by
numerous pest problems (e.g., insects, weeds, nematodes, and plant
pathogens), and these problems are expected to escalate because of the
increasing acreage being devoted to this crop (Turnipseed et al. 1979).
One way to explore alternative strategies for the management of
soybean pests is through the utilization of crop/pest models, where the
models are mathematical representations (computer simulated) of the
interactions between the crop and its principal pest-species (Stimac and
O'Neil 1985). Crop/pest models can be used "to simulate the dynamics of
a crop and pests in a single field so that decisions can be made
regarding pest management and other production practices for that field.
The objective of building a crop/pest model is to describe the dynamics
of the crop and pests in the context of the environment in which they
coexist. The environment includes many factors influencing the growth
of the crop and pest populations: weather inputs, such as temperature,
1

- 2 -
rainfall and solar radiation; biological inputs, such as natural enemies
of the pests; and production system inputs, such as irrigation,
cultivation, and application of pesticides" (Stimac and O'Neil 1985, pp.
323-324). These factors must be quantified and mathematically described
in submodels of the crop, pests, and production tactics.
One of the objectives of a multi-university investigation* was to
construct a soybean crop model that could be used to evaluate soybean
production strategies under various combinations of stresses (e.g.,
water or pests). To accomplish this objective, the Soybean Integrated
Crop Management (SICM) model was constructed. This model is composed of
an aggregate of submodels coupled to a physiologically-based plant-
growth model of soybean, and is designed to allow the user to study
various management strategies at the field level for different weather,
cultural, soil, pathogen, weed, and insect scenarios (Wilkerson et al.
1982, 1983).
One of the SICM submodels represents the population dynamics of
velvetbean caterpillar (VBC), Anticarsia gemmatalis Hubner (Lepidoptera:
Noctuidae), a major defoliating pest of soybean (Herzog and Todd 1980,
Wilkerson et al. in press). In the current version of the VBC submodel,
immigration of VBC adults into soybean has been difficult to assess
because no data of adult or egg density are available (see Wilkerson et
al. 1982). Data on adult density are essential for model
initialization, as VBC life stages do not overwinter in soybean and
infestation depends on the annual immigration of adults into soybean
investigation entitled The Development of Comprehensive, Unified,
Economically, and Environmentally Sound Systems of Integrated Pest
Managementfunded by the Environmental Protection Agency and the
United States Department of Agriculture.

- 3 -
fields (see Herzog and Todd 1980, Wilkerson et al. 1983). Furthermore,
egg density data are essential for model construction because the mere
presence of adults does not connote the presence of eggs and the
resultant defoliating larvae. The absence of VBC immigration data is
not surprising because the control recommendations for most pests are
designed without consideration for quantitative estimates of pest
immigration (see Barfield and O'Neil 1984).
To assess immigration in the current version of the VBC Submodel,
adult and egg densities were estimated from larval densities (Stimac,*
personal communication). Changes in the density and timing of adult
influx resulted in notable differences in soybean yield and grower
profit (see Table 1.1). With density varied and timing of influx held
constant, profit per hectare varied from $169.21 (low density) to
-$214.26 (high density). With influx timing varied and density held
constant, profit per hectare varied from $178.43 (late influx) to
-$289.63 (early influx). Without VBC (i.e., a simulation control),
profit per hectare was $241.61, the highest of all the simulations.
Clearly, the need to investigate VBC immigration into soybean was
delineated through the use of these simulations.
Present research goals were to (1) investigate the immigration of
VBC adults into soybean, (2) explore the interactions between soybean
phenology and VBC adults, and (3) quantify adult and egg densities in
soybean. These goals were accomplished by the construction of an adult
*J. L. Stimac, Associate Professor, Department of Entomology and
Nematology, University of Florida, Gainesville, FL 32611. Larval
densities at time "t" were used to determine egg and adult densities at
time "t-1" by calculating the densities of adults and eggs required to
produce the known larval densities. Mortality values of adults and
eggs were used in these calculations.

- 4 -
Table 1.1. Comparison of soybean yield and profit among
various densities and timings of adult velvetbean
caterpillar influx, as simulated with the Soybean
Integrated Crop Management model (modified from
Wilkerson et al. 1982). Soybean was not irrigated
in any simulations.
VBC3
Density
Influx^
Timing
Yield
(Kg/ha)
Profit
($/ha)
Low
Normal
1896.18
169.21
Average
Normal
1493.02
65.70
High
Normal
403.97
-214.26
Average
Early
110.32
-289.63
Average
Normal
1493.02
65.70
Average
Late
1931.86
178.43
None
None
2177.57
241.61
aHigh = +0
^Early was
.5 Average;
30 days prior
Low = -0.5 Average.
to normal and late was
30 days later
than normal.

5
and egg population model. The objective of this model is to mimic the
number of eggs laid by VBC adults in a 1 ha soybean field. To
accomplish this objective, experiments were conducted to understand or
quantify (1) egg identification, (2) egg developmental rates, (3)
estimates of the absolute density of eggs, (4) adult identification, (5)
observations of adult behavior in the field, (6) estimates of the
relative and absolute densities of adults, (7) categories of female
reproductive states, and (8) the impact of various environmental
variables (e.g., temperature) on adult and egg dynamics. Experimental
methods, results, and discussions are presented in the chapters and
appendices that follow.
Chapter II is a general review of soybean ecology, VBC ecology, and
VBC/soybean interactions. Chapter III is a study on the field behavior
of adult VBC. Chapter IV is a study on sampling for adults, of the
relationships between adult density and selected environmental
variables, and of the determination of female reproductive categories.
In Chapter V, an egg sampling technique and egg density data are
presented. In Chapter VI, a model of VBC adult and egg populations is
presented, and Chapter VII contains the summary and conclusions.

CHAPTER II
LITERATURE REVIEW
Introduction
Accomplishment of present objectives (see Chapter I) demanded that
soybean, velvetbean caterpillar (VBC), and the environment of both be
viewed as interacting components of a system. Velvetbean caterpillar
use soybean as an adult ovipositional substrate (see Greene et al.
1973), a larval food source (see Moscardi et al. 1981a), and an adult
habitat (see Herzog and Todd 1980). Soybean foliage and yield decrease
with VBC larval consumption (Strayer 1973), and temperature affects the
growth of both species (see Parker and Borthwick 1943, Johnson et al.
1983). Obviously, to view soybean and VBC as components of a system
requires an understanding of the ecology of each species. The objective
of this chapter is to review briefly the ecology of soybean and VBC,
their relevant interactions, and environmental factors that affect both.
Soybean Ecology
Soybean, Glycine max (L.) Merrill, became a domesticated species
probably in the North China Plains around the 11th century (Hymowitz
1970). The progenitor species apparently was G. ussuriensis Regel and
Maack (Morse et al. 1949). Polhill and Raven (1981) provide part of the
hierarchical classification for soybean as follows:
Order: Rosales
Family: Leguminosae
Subfamily: Papilionoidae
- 6 -

7
Tribe: Phaseoleae
Subtribe: Glycininae
Introduced into the United States as early as 1804, this legume did not
become an important crop in this country until about 1890 (Morse 1927).
Soybean currently is distributed worldwide (Weiss 1983).
General Description
Soybean is a summer annual, usually bushy and upright, and 30-122
cm in height (McGregor 1976, Weiss 1983). The main stem has 14-26
nodes; however, the first 2 nodes actually are composed of 2 opposite
nodes. Two cotyledons are borne at the first node, whereas the second
node bears two primary leaves. All other nodes on the main and lateral
stems bear alternate and pinnate trifoliolates on long petioles;
however, some multi-foliolate lines do occur (Shibles et al. 1975).
Pubescence occurs on most of the above-ground plant surface and may act
as a resistance mechanism to insect oviposition or feeding (see
Kobayashi and Tamura 1939, Nishijima 1960, Kogan 1975, Turnipseed 1977,
Oliveira 1981).
"The root system is extensive, with a tap-root which may exceed 1.5
m in length, giving rise to many lateral branches usually in the 0-30 cm
horizon. However, there is considerable variation between cultivars in
respect of rate of growth, total amount, spread and degree of
penetration of roots. Roots initially elongate faster than above-ground
growth, and in the field under normal conditions, roots of rain-growth
plants will be twice as long as above-ground plant height at the
six-node stage" (Weiss 1983, p. 344). Root nodules occur due to
symbiosis with a nitrogen fixing bacterium, Bradyrhizobium japonicum

- 8 -
(Buchanan 1980) comb, nov.* (see Weiss 1983). From a study on the
partitioning of C14 photosynthate in soybean, Housely et al. (1979)
speculate that less carbon is channeled into amino acids of nodulated
plants, as opposed to non-nodulated plants. The significance of this
channeling is unclear, but perhaps nodulated soybean can channel more
carbon into seed formation and plant defense.
Development and Growth
Fehr and Caviness (1977) describe and illustrate the stages of
soybean development based on vegetative and reproductive states (Tables
2.1 and 2.2). Soybean is a short-day plant, and reproduction (or
flowering) is triggered by photoperiod (Garner and Allard 1930).
Temperature and variety can be important in determining the beginning of
flowering (van Schaik and Probst 1958, Fehr and Caviness 1977).
Flowering occurs over a four to six-week period (Shibles et al. 1975).
Flowers are self-pollinated (Shibles et al. 1975, McGregor 1976), but
Erickson (1975) demonstrated a significant yield increase in two
varieties due to honey-bee, Apis mellifera L., pollination. Soybean
flowers do produce nectar (Jaycox 1970) and possess most, if not all, of
the anatomical adaptations of entomophilious plants (e.g., the nectar
guide)(Erickson and Garment 1979).
Soybean exhibits two types of growth habit, determinate and
indeterminate. Canopies of these two growth types are distinctly
different. The largest leaves of indeterminates occur at the center of
the plant, with gradations in size toward each end of the stem. With
determinate cultivars, all mature leaves above the middle of the plant
*Synonym is Rhizobium japonicum Buchanan (Jordon 1982).

- 9 -
Table 2.1. Description of soybean vegetative stages (Fehr and Caviness
1977).
Stage
Stage Title
Description
VE
Emergence
Cotyledons above the soil surface.
VC
Cotyledon
Unifoliolate leaves unrolled sufficiently
so that leaf edges are not touching.
VI
First-Node
Fully developed leaves at unifoliolate nodes.
V2
Second-Node
Fully developed trifoliolate leaf at node
above the unifoliolate nodes.
V3
Third-Node
Three nodes on the main stem with fully
developed leaves beginning with the
unifoliolate nodes.
V (n)
nth-Node
The number of nodes on the main stem is equal
to 'n', beginning with the unifoliate nodes.

10 -
Table 2.2. Description of soybean reproductive-stages (Fehr and
Caviness 1977).
Stage Stage Title
Description
R1 Beginning Bloom
One open flower at any node on the
main stem.
R2 Full Bloom
Open flower at one of the two
uppermost nodes on the main stem with
a fully developed leaf.
R3 Beginning Pod
Pod 5 mm long at one of the four
uppermost nodes on the main stem with
a fully developed leaf.
R4 Full Pod
Pod 2 cm long at one of the four
uppermost nodes on the main stem with
a fully developed leaf.
R5 Beginning Seed
Seed 3 mm long in a pod at one of the
four uppermost nodes on the main stem
with a fully developed leaf.
R6 Full Seed
Pod containing a green seed that fills
the pod cavity at one of the four
uppermost nodes on the main stem with
a fully developed leaf.
R7 Beginning Maturity
One normal pod on the main stem that
has reached its mature pod color.
Mature pod color varies with variety.
R8 Full Maturity
Ninety-five percent of the pods that
have reached their mature pod color.
Five to ten days of drying weather are
required after R8 before the soybeans
have less than 15% moisture, and can
be harvested.

11
are approximately the same size, and their resultant canopies are
thought to have poorer light-distribution characteristics.
Indeterminate cultivars continue to grow vegetatively during flowering,
and early pod, and seed development. Flowering begins when these
cultivars have reached about half their height and continues as the
plant grows taller. For determinate varieties, plants reach full height
at flowering and flowers emerge at approximately the same time from all
nodes (Fehr et al. 1971, Shibles et al. 1975, Fehr and Caviness 1977).
Fehr and Caviness (1977) provide average and range estimates of
soybean development between stages (see Table 2.3). The average number
of days for complete development is 125, with a range of 74 to 218. The
large range in developmental time results from effects of temperature,
variety, photoperiod, and water stress (Doss et al. 1974, Fehr and
Caviness 1977) The major factor that influences vegetative growth is
temperature. Seedling emergence and leaf development are retarded by
low temperatures and enhanced by high temperatures (Fehr and Caviness
1977).
Soybean leaves exhibit Calvin-cycle photosynthesis, but stems and
pods also contribute to carbon dioxide uptake (Weiss 1983). Leaf area
production begins slowly, then increases rapidly and increases almost
linearly during mid-vegetative growth. Maximum leaf-area index (LAI*)
values of five to eight can be achieved by late flowering. During seed
filling and after flowering, LAI declines progressively by abscission of
lower leaves (Shibles et al. 1975).
*Leaf Area Index (LAI) is "the surface area of leaves per unit surface
area of ground" (Lewis 1977, p. 87).

12 -
Table 2.3. Average and range of developmental time required for a
soybean plant to develop between stages (Fehr and Caviness
1977).
Stage
Average3
Developmental Time
(day)
Range in*5
Developmental Time
(day)
0C VE
10
5
-
15
VE VC
5
3
-
10
VC VI
5
3
-
10
VI V2
5
3
-
10
V2 V3
5
3
-
8
V3 V4
5
3
-
8
V4 V5
5
3
-
8
V5 V6
3
2
-
5
R1 R2
0d, 3
0
-
7
R2 R3
10
5
-
15
R3 R4
9
5
-
15
R4 R5
9
4
-
26
R5 R6
15
11
-
20
R6 R7
18
9
-
30
R7 R8
9
7
-
18
Average total developmental time is 125 days.
^Range varies from 74 to 218 days.
q
0 = planting
dRl and R2 generally occur simultaneously in determinate varieties.
The time interval between R1 and R2 for indeterminate varieties is
about three days.

13 -
Water Stress
"Soybeans use a lot of water" (Shibles et al. 1975, p. 159). With
sufficient water, total water use from beginning bloom to maturity is
nearly the equivalent of 95% open-pan evaporation (Peters and Johnson
1960). Water consumption by soybean is determined substantially by leaf
area until full ground-cover is achieved. After full ground-cover,
evaporative demand is the most influential variable. Leaf area
distribution and water supply also affect water consumption. Soybean is
water-stressed easily and may be under water stress more frequently and
severely than many other plants. Water stress is caused by soil water
deficit or high evaporative demand. Even on wet soils, plants can
exhibit wilting under high evaporative demand (Shibles et al. 1975).
Susceptibility to Insect Attack
Soybean is susceptible and sensitive to insect attacks for at least
three reasons: (1) It is grown in monoculture in large acreages
approximately 25 million hectares were harvested in the United States in
1983 (see FAO 1984). The "plant apparency" of soybean, due to this
acreage, makes it potentially highly vulnerable to insect herbivory (see
Feeny 1975). (2) As part of a simplified agroecosystem with high-
energy input, soybean, like other crops of the Green Revolution,* is
highly susceptible to insect attack (see Perelman 1977, Altieri 1983).
(3) Soybean may have inadequate defenses against many insects, as man has
introduced soybean into the range of these insects. For example, VBC
apparently evolved in the Neotropical region (see Buschman et al. 1977)
while soybean evolved elsewhere (see Weiss 1983).
*The Green Revolution is an attempt to solve crop production problems
through the development of high-yielding varieties that require high
inputs of pesticides, fertilizers, irrigation, and machinery.

14 -
Velvetbean Caterpillar Ecology
Anticarsia gemmatalis Hubner was described by Hubner (1816, cited
by Ford et al. 1975). Kimball (1965) and Borror et al. (1981) provide
part of the hierarchial classification for this insect as follows:
Order: Lepidoptera
Suborder: Ditrysia
Superfamily: Noctuoidea
Family: Noctuidae
Subfamily: Erebiinae.
Seven synonyms for gemmatalis are listed by Schaus (1940). The
common name for A^_ gemmatalis, as accepted by the Entomological Society
of America, is the velvetbean caterpillar (Sutherland 1978). Severe
defoliation of velvetbean (Stizolobium deeringianum Bort.) by this
insect in the early 1900's resulted in its common name (Chittenden 1905,
Watson 1916a).
Distribution
The VBC is a tropical to subtropical species of the Western
Hemisphere (Ford et al. 1975) and ranges over much of North and South
America, and all of Central America and the West Indies. In North
America, the northern limits of the range are slightly above the 45N
parallel, extending into Ontario and Quebec, Canada. In South America,
the southern limit of the range appears to be approximately the 35S
parallel, extending to Buenos Aires, Argentina (Ford et al. 1975, Herzog
and Todd 1980).
The range of VBC in North America fluctuates temporally due to (1)
suspected migration of adults (Watson 1916a), (2) winter mortality of
immature stages (Buschman et al. 1981a), and (3) lack of occurrence of
immature stages (Ellisor 1942, Buschman et al. 1977, Waddill et al.

15
1982). Evidence to support migration is either speculative (see Watson
1916a) or indirect (Baust et al. 1981, Buschman et al. 1981a). No
intensive studies of adult distribution in the winter exist, nor have
direct-evidence studies (e.g., capture, mark, release, recapture) of
adult migration been made. The 28N parallel has been indicated as the
northern limit for winter distribution (Buschman et al. 1977), but some
reports appear to conflict with this limit. A number of adults were
caught in Gainesville, FL, following a freeze that occurred on 21
November 1914 (Watson 1915). Adults were caught again in Gainesville on
29 January 1916 (Watson 1916a) and on 4 March 1932 (Watson 1932) at the
2938'N parallel, 188 km above the 28N parallel.
Life Stages
A description of VBC life stages is given by Watson (1916a) as egg,
six larval instars, pupa, and adult. The egg is nearly 2 mm in
diameter, less than 2 mm in height, prominently ribbed, and flattened on
its lower surface (Watson 1916a). Egg coloration varies greatly:
white, delicate pink, pale green, cryptic green, orange, reddish brown,
transparent, slightly green, and green with red marks (see Watson 1916a,
Douglas 1930, Hinds 1930, Ellisor 1942, Greene et al. 1973, Gutierrez
and Pulido 1978). Larvae vary greatly in color and markings,
particularly after the second instar. Longitudinal lines are usually
black, white, yellow, or pink. Background color varies from light
yellowish-green to mahogany brown. Length of a sixth instar larva
varies from 38 to 48 mm (Watson 1916a).
Pupae are light green for approximately 24 hours, then turn brown.
Pupation occurs usually at or below soil surface and in a loose, frail,
earthen cell (Watson 1916a, Hinds 1930). Dorsal wing coloration of the
adults is highly variable, with color ranging from ashen gray to light

16 -
yellowish-brown to reddish brown (Watson 1916a, Kimball 1965, Leppla et
al. 1977). Ventral coloration is more consistent, a cinnamon brown with
a submarginal row of white spots (Watson 1916a). Sexual dimorphism of
adult leg scales allows for accurate and rapid sexual identification.
Males have tufts of long setae that are present on the femora of
prothoracic legs and the tibiae of metathoracic legs. These long setae
are absent on female legs (Anonymous 1974).
Life History
The life history of VBC in the field is discussed by Watson
(1916a), Douglas (1930), Hinds (1930), Hinds and Osterberger (1931),
Ellisor (1942), Buschman et al. (1977), Gutierrez and Pulido (1978), and
Buschman et al. (1981a). Leppla (1976) and Leppla et al. (1977) report
the life history under laboratory conditions. Larval development and
consumption on different phenological stages of soybean are reported by
Reid (1975), Moscardi et al. (1981a), and Olivera (1981). Nickle (1976)
gives larval consumption rates on peanut leaves. Moscardi et al.
(1981b) and Olivera (1981) report the effect of different soybean
phenological stages on VBC oviposition, egg hatch, and adult longevity.
Finally, Moscardi et al. (1981c) demonstrate the effects of temperature
on oviposition, egg hatch, and adult longevity, and Johnson et al.
(1983) present a temperature-dependent developmental model of VBC.
Adult Behavior
Field and laboratory studies have been conducted on adult behavior.
In general, the field studies have been qualitative, with little
quantification of data. The reverse exists for the laboratory studies.
Observations of adults with regard to oviposition, mating, feeding, and
flight activity are reported by Watson (1916a), Douglas (1930), Hinds
(1930), Greene et al. (1973), and Ferreira and Panizzi (1978). Greene

17
et al. (1973) present the most detailed observations, but their data
were collected over a short, seven-day time period. Johnson et al.
(1981) report a behavioral study on the response of VBC to its
pheromone. Heath et al. (1983) elucidate the chemical composition of
VBC pheromone and the pheromonal effect on male and female behavior.
Leppla (1976) and Leppla et al. (1979) indicate the circadian rhythms of
locomotion and reproductive behavior of adults in the laboratory. Wales
et al. (1985) demonstrate the flight and ovipositional dynamics of adult
females during tethered flight.
Host Plants
At least 40 legumes and five non-legumes appear to serve as host
plants for larvae of the VBC (Table 2.4). The authenticity of many of
the records in Table 2.4 is questionable because they were not
accompanied with (1) host scientific name, (2) confirmation of
oviposition, (3) verification of complete larval development, (4)
verification of larval and host identities, and (5) multiple sightings.
Based on these records VBC probably is restricted to leguminous host
plants and is therefore either monophagous (see Krieger et al. 1971) or
oligophagous (see Slansky 1976).
Velvetbean caterpillars appear to have a marked preference for
soybean over other hosts. Douglas (1930) states that neither larvae nor
feeding damage was sighted, except on soybean, in fields planted with
soybean and the following crops: cotton,* kudzu, cowpea, and
velvetbean. Hinds and Osterberger (1931) note a similar preference for
soybean grown with velvetbean, cowpea, and other legume crops (names
*Some larvae crawled from completely defoliated soybean to cotton and
fed on the cotton. Complete larval-development on the cotton was not
assessed.

Table 2.4.
Reported host plants of larval velvetbean caterpillar (modified from Moscardi 1979, Herzog
and Todd 1980).
Family Scientific Name
Common Name
Reference
Leguminosae Aeschynomenes sp.
Agati grandiflora (L.) Desv.
Arachis hypogaea L.
Cajanus cajans (L.) Millsp.
Cajanus indicus Spreng
Canavalia gladiata (Sav.)
Canavalia martima Aub.
Canavalia rosea Sw.
Canavalia sp.
Joint Vetch
Gallito Trees
Peanut
Pigeon Pea
Pigeon Pea
Sword Bean
de Cond.
Horse Bean
Canavalia
Cassia fasciculata Michx.
Cassia obtusifolia L.
Desmodlum floridanum Chapm.
Partridge Pea
Coffeeweed
Beggar Lice
DPIb
Wolcott (1936)
Anonymous (1928)
McCord (1974)
DPIb
Ellisor (1942)
Buschman et al. (1977)
Tietz (1972)
Watson (1916a), Ellisor (1942),
Tietz (1972)
Herzog (unpublished)
Buschman et al. (1977)
Buschman et al. (1977)

Table 2.4 (continued)
Family
Leguminosae
Scientific Name
Dolichos lablab L.
Galactia spiciformis
Glycine max (L.) Merrill
Indigofera hirsuta L.
Lespedeza sp.
Medicago sativa L.
Melilotus alba Desr. in Lam.
Pachyrhizus erosus (L.) Urban
Phaseolus calcaratus Roxb.
Phaseolus lathyroides L.
Phaseolus limensis Macf.
0
Phaseolus max
0
Phaseolus semierectus
Phaseolus speciosus H.B.K.
Common Name
Reference
Hyacinth Bean
Buschman et al. (1977)
Galactia
Torr. and Gray
Buschman et al. (1977)
Soybean
Nickels (1926)
Hairy Indigo
Buschman et al. (1977)
USDA (1954a)
Alfalfa
Ellisor and Graham (1937)
White Sweet Clover
Waddill (1981)
Yam Bean
Buschman et al. (1977)
Frijolito Rojo
Gutierrez and Pulido (1978)
Wild Bean
Buschman et al. (1977)
Lima Bean
Ford et al. (1975)
Wolcott (1936)
Tietz (1972)
Sweet Pea Vine
Buschman et al. (1977)

Table 2.4 (continued)
Family
Leguminosae
Scientific Name
Phaseolus vulgaris var.
Pisum sativum L.
Pisum sp.
Pueraria lobata Willd.
Pueraria phaseoloides (Roxb)
Pueraria thumbergiana
(Siebold and Zucc.) Benth
Rhynchosia minima L.
Robinia pseudoacacia L.
Sesbania emerus (Aubl.)
Britton and Wilson
Sesbania exaltata (Raf.)
V.L. Cory
Sesbania macrocarpa Muhlenb.
ex Raf.
Common Name
Reference
Bush Bean
humilis Alef.
Ford et al. (1975)
English Pea
DPIb
Field Pea
DPIb
Kudzu
Buschman et al. (1977)
Tropical Kudzu
Benth
Ford et al. (1975)
Kudzu Vine
Watson (1916a)
Least Rhynchosia
Buschman et al. (1977)
Black Locust
Ellisor (1942)
Long Pod
DPIb
Sesbania
Tietz (1972)
Coffee Weed
Hinds and Osterberger (1931)

Table 2.4 (continued)
Family Scientific Name
Common Name
Reference
Leguminosae
Stizolobium deeringianum Bort.
Velvetbean
Chittenden (1905)
Tephrosia sp.

USDA (1954b)
Vigna luteola Jacq.
Vigna
Buschman et al. (1977)
Vigna repens (L.) Kuntze
Cowpea
DPIb
Vigna sinensis (L.) Endl.
Cowpea
Hinds and Osterberger (1931)
Begoniaceae
Begonia sp.
Begonia
DPIb
Gramineae
Oryza sativa L.
Rice
Tarrago et al. (1977)
Triticum sp.
Wheat
Wille (1939)
Malvaceae
Gossypium herbaceum L.
Cotton
Douglas (1930)
Hibiscus esculentus L.
Okra
Todd (unpublished)*^

Table 2.4 (continued)
g
The authenticity of many of these records is questionable because they were not accompanied with (1)
host scientific name, (2) confirmation of oviposition, (3) verification of complete larval development,
(4) verification of larval and host identities, and (5) multiple sightings.
^Host records on file at Florida Department of Agriculture and Consumer Services, Division of Plant
Industry (DPI), Gainesville, FL 32611.
c
D. C. Herzog, Professor, Entomology and Nematology Department, University of Florida, Agriculture and
Education Center, Quincy, FL 32351.
^J. W. Todd, Assoc. Professor, Department of Entomology, University of Georgia, Georgia Coastal Plain
Experiment Station, Tifton, GA 31794.
0
Author unknown.
i
ho
ro
l

- 23 -
not provided). Ellisor and Graham (1937, p. 278) state that "moths
select soybeans in preference to velvet beans for oviposition, even when
the two crops are grown in adjacent fields." Ellisor (1942) reports
soybean is preferred to alfalfa, cowpea, peanut, and velvetbean. Oddly,
no studies of VBC and its hosts, except for soybean (see Moscardi et al.
1981a, 1981b) and peanut (see Nickle 1976), have been conducted to
assess complete larval development, and adult eclosin.
Natural Enemies
An extensive review and discussion of the parasitoids, predators,
and pathogens of VBC is provided by Moscardi (1979). Two striking
generalizations about VBC natural enemies that emerge from a synthesis
of Moscardi's review are (1) the predators and parasites are generalists
and (2) the pathogens are highly specific. O'Neil (1984) reports that
predators are unable to control VBC populations because the predators
are generalists and do not search sufficient leaf area. At the present
time, pathogens appear to be the best natural enemy for controlling VBC
populations (see Kish and Allen 1978).
Sampling and Economic Thresholds
Sequential sampling and economic thresholds for management of VBC
larvae in soybean are presented by Strayer (1973). Estimates of the
relative and absolute densities of larvae in soybean are presented by
Luna (1979). Linker (1980) provides sampling procedures for larvae in
peanuts and soybeans, and presents an analysis of seasonal abundance.
Techniques and methodologies for sampling of all VBC stages are reviewed
and discussed by Herzog and Todd (1980).
Models
At least six models of VBC dynamics in soybean are reported. Menke
(1973) and Menke and Greene (1976) present a stochastic simulation model

24 -
in which VBC dynamics and soybean defoliation are examined. Kish and
Allen (1978) present a model predicting the incidence of Nomuraea rileyi
(Farlow) Samson on VBC larvae. Luna (1979) reports an economic
threshold model for chemical control of VBC larvae on soybean. O'Neil
(1984) presents a model of predation on larvae. Predator and VBC
densities, soybean leaf-area, and predator searching-behavior are
incorporated into O'Neil's model. The Soybean Integrated Crop
Management (SICM) model is a soybean plant-growth model that is coupled
to multiple stress submodels (e.g., an insect-pest submodel). One of
these submodels represents the population dynamics of the velvetbean
caterpillar (Wilkerson et al. 1983). Wilkerson et al. (in press)
present a temperature dependent VBC dynamics model.
Velvetbean Caterpillar as a Soybean Pest
Velvetbean caterpillars are a chronic and primary pest of soybean
for many reasons. Adults are highly mobile, exhibit early reproduction,
and have a very high reproductive rate, while larvae develop rapidly and
exhibit high survival. In short, VBC appears to be an r-strategist*
(see MacArthur and Wilson 1967) Adults are caught as far north as
Canada (Watson 1916a) and on oil-rig platforms in the Gulf of Mexico
(Baust et al. 1981). Further, adults exhibit a low wing-loading ratio**
that may require little energy for flight and may be an adaptation for
flying long distances in search of host plants (Angelo and Slansky
1984); larvae utilize host plants that are widely dispersed and
*The crucial evidence needed for r- and K-selection is whether an
organism allocates a greater proportion of its resources to
reproductive activities (r-strategist) than another related organism
(K-strategist) under any and all density-dependent and
density-independent mortality conditions.
**Wing loading ratio is body weight/wing area.

25
ephemeral (see Herzog and Todd 1980), so adults must be able to fly
between hosts. Mated females exhibit early reproduction, laying 50% of
their eggs within four to nine days after emergence, and with
oviposition steadily declining thereafter (Moscardi et al. 1981c).
Total mean oviposition, for females reared as larvae on soybean, can be
as high as ca. 963 eggs/female, with an extremely high net reproductive
rate of ca. 365 (Moscardi et al. 1981b). In conjunction with this high
reproductive rate, the mean developmental time from egg hatch to adult
eclosin is ca. 22 days (Moscardi et al. 1981a). Finally, immature VBC
stages exhibit high survival, except for larval mortality during late
soybean growth from the pathogen, N. rileyi (Kish and Allen 1978, Elvin
1983, O'Neil 1984).
Velvetbean Caterpillar/Soybean Interactions
The VBC is believed to overwinter in southern Florida, the West
Indies, Central America, and much of South America. This pest is
hypothesized to migrate each year from overwintering areas into the
southern United States (Watson 1916a, Herzog and Todd 1980, Buschman et
al. 1981a). The temporal occurrence of immigration is unknown, as no
direct evidence exists (Buschman et al. 1981a), but moths invade soybean
fields in northern Florida from May to July (Greene 1976). Following
colonization, larvae reach peak densities in August or September, or
occasionally in early October (see Greene 1976, Linker 1980). As
soybean senesces, usually in mid to late October, larval populations
decline rapidly and VBC adults move to different hosts, both cultivated
and wild (Ellisor 1942, Greene 1976, and Buschman et al. 1981a). Larvae
and pupae apparently are incapable of overwintering in soybean fields,
so infestation of soybean the next year begins with adult immigration
(Watson 1916a, Buschman et al. 1981a).

26 -
Soybean and VBC interact in several ways: (1) oviposition by
moths, (2) foliage consumption by larvae, (3) nutritional quality of
plants, and (4) canopy dynamics of the plants. Soybean serves as an
ovipositional substrate (Greene et al. 1973), and differences in
infestation levels on some varieties may be due to an ovipositional
preference (see Genung and Green 1962). Soybean varieties and
phenological stages vary nutritionally (see Hammond et al. 1951,
Henderson and Kamprath 1970, Hanway and Weber 1971), and this variation
significantly affects VBC development, consumption, survivorship, and
reproduction (Moscardi et al. 1981a, Moscardi et al. 1981b, Reid 1975,
Oliveira 1981). Also, as larvae develop, their consumption rate
(cm2/day) increases: instar 2 = 0.31; instar 3 = 1.47; instar 4 = 3.94;
instar 5 = 8.11; and instar 6 = 14.39 (Reid 1975).
The dynamics of the soybean canopy have an enormous effect on two
aspects of VBC dynamics: (1) adult colonization and (2) larval
mortality. Colonization by adults may be related to changes in soybean
canopy (see Chapter IV). Canopy dynamics affect larval mortality in
four ways. First, canopy closure establishes favorable microclimatic
changes that can lead to an epizootic of Nomuraea rileyi (Farlow)
Samson, an entomopathogenic fungus (Kish and Allen 1978). Second,
mortality rates of immature VBC that have fallen to the ground are
significantly higher before the canopy closes due to high soil surface
temperature (Elvin 1983). Third, canopy leaf area is a key element in
the predator/prey dynamics of VBC larvae. Leaf-area increase provides a
spatial escape for VBC larvae (ONeil 1984). Fourth, female moths
appear to oviposit on the lowest two-thirds of the plant and small
larvae are apparently distributed in the bottom third of the canopy (see
Ferreira and Panizzi 1978). Mortality of eggs and small larvae may

27
decrease significantly after canopy closure because closed canopies are
darker than unclosed canopies and predators may not be able to see as
well in a closed canopy.
The completion of the present review of the ecology of soybean and
VBC, and their interactions, sets the stage for presentation of the
chapters that follow. In the next chapter (Chapter III), a description
of the behavioral ecology of adult VBC within soybean is presented.
Observations of adult behavior in the field were necessary for the
design and implementation of the experiments presented in the chapters
that follow Chapter III.

CHAPTER III
BEHAVIORAL ECOLOGY OF ADULT VELVETBEAN CATERPILLAR
Introduction
Ethology, the study of behavior, has been slow to emerge as a
scientific discipline (Kennedy 1972, McFarland 1976). This slow
emergence seems odd, particularly with respect to pests, because pest
management mandates an understanding of pest behavior (Kennedy 1972,
Lloyd 1981, Gould 1984, Lockwood et al. 1984). Ignorance of the
behavioral ecology of pests has led to a poor understanding of
population dynamics and management (see Kennedy 1972, Stimac 1981, Burk
and Caulkins 1983, Barfield and O'Neil 1984).
Insect behavioral data, particularly for pests, is limited (Nielsen
1958, Matthews and Matthews 1978). Not surprisingly, information on the
behavioral ecology of adult velvetbean caterpillar (VBC), a major pest
of soybean in the Gulf Coast area of the United States, is sparse (see
Greene et al. 1973, Herzog and Todd 1980). The present study on the
behavioral ecology of adult VBC was initiated as part of a project to
explore the movement of adults into soybean. To examine this movement
quantitatively, a mathematical relationship needed to be established
between adult and egg densities in a soybean field (see Chapter VI). To
obtain estimates of adult and egg densities (see Chapters IV and V), and
to establish a relationship between these estimates, a number of
questions about adult behavior in the field had to be resolved: (1) Did
flight activity vary through time? (2) Did ovipositional occurrence and
frequency vary through time? (3) What environmental factors affected
- 28 -

- 29 -
flight activity and oviposition? and (4) What environmental factors
affected the movement of adults in and out of soybean? In addressing
these questions, additional behavioral observations were recorded.
Literature Review
General Activity
Circadian rhythms of locomotion for colonized adults have been
determined with a vibration-sensitive actograph (Leppla 1976). Males
and pairs were diurnal predominately during the first 6 days after
emergence and nocturnal from the sixth day until death. Females became
nocturnal within 48 h of emergence. The general activity of adults in
all categories (i.e., isolated sexes and pairs) was age dependent; most
activity occurred in the first week after emergence. For paired adults,
74% of all activity was expressed during the first week.
Flight in the Laboratory
Circadian rhythms of flight frequency for colonized adults were
determined with an actograph system (Leppla et al. 1979). Flight
activity, monitored for 18 days, was exceptionally erratic. Nocturnal
and diurnal flights were common during the first six days after
emergence for isolated sexes and pairs. Following the sixth day,
flights were nocturnal predominately. No significant differences in
flight activity were noted among males, females, or pairs, but pairs
exhibited the least activity and isolated females exhibited the most
activity. Flight activity for all categories decreased with age.
A pivot-stick actograph was used to examine tethered flight of VBC
adults (Wales et al. 1985). No significant differences were detected
with regard to mean flight frequency (number of flights) or mean flight
duration (time of flight) among all seven comparisons of colony versus
wild adults and mated versus unmated adults. For mated and unmated

30 -
colony females, mean dally flight frequencies were erratic, but
relatively few flights were made in early adult life. No obvious
patterns in the hourly distributions of flight frequency for colony or
wild females, mated or unmated, were detected. For mated and unmated
colony females, mean daily flight durations were erratic, but relatively
short flight times were displayed in the second through fourth days. No
obvious patterns in the hourly distributions of flight duration for
colony or wild females, mated or unmated, were detected.
Flight in the Field
Flight activity in the field can be partitioned into three
categories: (1) migratory, (2) movement among various hosts, and (3)
within field. Migration of adults is reviewed in Chapter II, and
movement among hosts is discussed in Chapter IV where relevant adult-
density data are presented. Reports of within-field flight activity
(i.e., daily flight activity) will be reviewed in this chapter.
Watson (1915, 1916a, 1916b), the first to report on flight activity
of VBC, made several observations in velvetbean, Stizolobium
deeringianum Bort.
Although apparently capable of prolonged journeys, the moths as
observed in the field, do not ordinarily take long flights. They
hang about the velvet bean plants closely, coming out for short
flights about sunset. If disturbed, they dart away rapidly but
usually fly only a few yards and do not rise high above the vines.
(Watson 1915, p. 59)
Dusk is the period of greatest activity of the moths. During the
day they lie hidden under the leaves of the host plants. If
disturbed they fly a short distance only. (Watson 1916a, p. 525)
The moths fly mostly toward sunset, but fly up at any time during
the day if the vines are disturbed as by one walking through them.
They do not rise high into the air but keep close to the ground and
where the shade of the vines is dense. (Watson 1916b, p. 11)

- 31
Douglas (1930) indicated that adults were night-flying moths, were
inactive in soybean during the day and, if disturbed, exhibited a very
swift flight. Ellisor (1942, p. 18) noted:
The moths are inactive in the day, usually resting on the ground or
close to the ground on leaves or other debris, and when disturbed
make darting flights for short distances and again become inactive.
Late in the afternoon they become active and can be seen darting in
and out of the plants.
The most detailed observations of flight were reported by Greene et
al. (1973). Moths were observed with a flashlight and a propane lantern
in a 1.83 x 1.83 x 3.66 m screen cage placed over soybean plants in a
field. "Observation of moths in daylight showed undirected flight
behavior. Disturbed moths flew into the cage walls, hit leaves and
other objects, and flew in undirected, sharp, angled patterns, similar
to the observations by Ellisor (1942). At sunset, moth activity in the
field was minor, but 30 min post-sunset, moth movement became directed,
slower, and much more controlled. Moths did not fly into the cage
walls; they would fly to the wall and light upon it; they would fly to a
leaf, flutter, and settle upon it, and they were observed not to bump
into objects. Moths on the cage walls at sundown moved to the plants
and by ca. lj h postsundown few were left on the cage walls" (Greene et
al. 1973, p. 1113).
Another report of flight activity in soybean was made by Gutierrez
and Pulido (1978). They reported that moths were fast fliers and flew
regularly during the night. During the day, moths remained on the soil
surface near the soybean plants or on the middle part of the plants.
Johnson et al. (1981) reported on the flight of colony males under
natural photoperiod in screenwire cages in a greenhouse; females were
present but were unable to fly. "Males became active ca. 45 min after

- 32 -
sunset. This activity was characterized by apparently indiscriminate
flight around the cage, followed by walking on the sides of the cage,
and rapid fluttering of wings" (Johnson et al. 1981, p. 529).
Mating
Watson (1915, p. 60) stated that, "mating undoubtedly takes place
at night." Watson (1916a, p. 525) furthered his observations when "a
single pair was observed mating in the cages [sic]. This occurred about
dusk. They remained in coitu only a few seconds."
The first detailed observations of mating behavior were published
by Greene et al. (1973). Observations were made during seven
consecutive scotophase periods inside a 1.83 x 1.83 x 3.66 m screen cage
placed over soybean. Male activity was observed when a female, "with
her moving wings outstretched horizontally" (Greene et al. 1973, p.
1113), pointed her abdominal tip dorsally (or ventrally as in one
observation). Males, usually two to five, were attracted from .61-1.83
m. A mating pheromone was postulated.
Greene et al. (1973) noted additionally that mating activity
consisted of five stages: pheromone release, male response, mounting by
the male, sperm transfer, and separation. Males flew in an upwind zigzag
pattern to locate a female. Females were approached from behind,
stroked vigorously with the male's antennae, and mounted dorsally for
1-10 sec (x = 5 sec). Males then rotated 180 toward the rear of the
female, so that their heads pointed in opposite directions. The legs of
both adults were on a leaf surface, and females always faced skyward.
Adults remained opposite to each other for the remainder of the
copulatory period, were docile if disturbed, and moved very little.
"The majority of the copulations began within 2 h postsunset and
considerably fewer after 10 PM. The time spent in copulation ranged

- 33 -
from 42 min to over 4 h and averaged 2 h 31 min." (Greene et al. 1973,
p. 1114). Copulations were observed on the cage wall, on the plants,
and in the field outside of the cage. Under natural field conditions,
mating occurred within the plant canopy, with both sexes grasping stems
or leaves. At the completion of copulation, the adults separated.
Usually the female walked a very short distance, remained on the same
plant leaf for a few minutes, and then flew away. Male activity after
separation was not described.
During a ten hour scotophase period in the laboratory, Leppla
(1976) watched 20-50 pairs of adults in three plexiglass cages over an
18-day period. No adults "called" or mated during their first day.
Mating peaked during the 2nd and 3rd day and declined steadily until it
stopped on the 16th day; mating activity was age-dependent. Mating
occurred at all hours of scotophase, with 19% occurring in the first 5
hours and 81% occurring in the second 5 hours. Mated females contained
an average of 1.7 spermatophores per female, with a range of 1-6
spermatophores. Males did not mate more than twice. "Typically, a male
flew to the female, engaged in the well-known lepidopteran 'courtship
dance,' approached the female from behind, moved forward to a parallel
position, mounted dorsally, clasped the genitalia of the female, and
swung down to face the opposite direction" (Leppla 1976, p. 47).
Johnson et al. (1981) confirmed the presence of a female sex
pheromone with behavioral observations and field bioassays. Colony
adults, observed in cages in a greenhouse, became active ca. 45 min
after sunset, but mating was not noted until ca. 2 h after dark. The
courtship sequence was initialized by a female with wing fanning and
dorsal elevation of the abdominal tip. The male response consisted of
flying in a zigzag path toward the female, hovering near the female

- 34 -
(usually with claspers extended), and landing or flying away. In the
field bioassay, male attractiveness to three females in a trap commenced
ca. 1 h after sunset and remained fairly uniform throughout the night.
Pheromone, extracted from females 4 h and 6 h after sunset, was more
attractive to males than pheromone extracted 9 h and 6 h before dark, at
sunset, or 2 h and 9 h after sunset. A significant decrease in male
capture was noted with increasing age of females. Also, mated females
were less attractive to males. The female sex-pheromone was identified
as a blend of (Z,Z,Z)-3,6,9-eicosatriene and (Z,Z,Z)-3,6,9-
heneicosatriene in a blended ratio of ca 5:3, respectively (Heath et al.
1983). Synthesized pheromone elicited responses by adult males
equivalent to those elicited by females in both laboratory bioassays and
field-trapping experiments (Heath et al. 1983).
Oviposition
Early reports of oviposition were not quantified. Watson (1916a)
noted most eggs were laid singly on the bottom leaf-surface of
velvetbean, but some were laid on the upper leaf-surface, petiole, and
stem. He also reported oviposition on the tender shoots, the underside
of the leaves (Watson 1915), mostly on the bottom of younger leaves
(Watson 1916b), and mostly on the bottom of mature leaves (Watson
1916c). Watson apparently was confused as to where the majority of eggs
were laid. Watson (1921, p. 2) further reported that, "the moths are
shade-loving creatures and collect under the vines in the densest shade
and there lay their eggs."
Douglas (1930) indicated that eggs were deposited singly on the
underside of soybean leaflets and sometimes on the upper leaflet
surface. Females often laid one egg per plant, sometimes several.
Hinds (1930) reported that eggs were deposited singly on soybean,

- 35 -
scattered about the plant and found on leaves and stems. On leaves, the
midrib was preferred because the pilosity was heaviest. Oviposition was
observed by Hinds (1930) at dusk and assumed to continue into the night.
Observations by Ellisor (1942) indicated the following: (1) oviposition
on soybean began in late afternoon and extended through the night, (2)
eggs were laid singly and many eggs were laid on each plant, (3) eggs
were found on the stems, seed pods, and leaves, and (4) eggs were found
often on the midrib and veins of a leaflet underside.
The only detailed observations of oviposition have been presented
by Greene et al. (1973). Wild adults in soybean were observed in a 1.83
x 1.83 x 3.66 m cage during scotophase over a seven-day period.
Observations started at sunset (ca. 2000) and stopped at 0300, except
for the first night when observations stopped at 0800. Females laid
eggs singly, but two or three eggs were laid occasionally at a given
site with the eggs ca. 1 cm apart. Females fluttered quickly between
ovipositional sites and deposited an egg in 2-60 sec. Frequently,
females exhibited ovipositional behavior but no eggs were laid. Eggs
were deposited on stems, pods, and leaf bottoms.
"Oviposition was closely observed several times and consisted of
the moth first clasping part of the plant with her feet, then arching
the tip of her abdomen ventrally. When the plant surface was touched by
her abdomen, it expanded; the conjunctiva anterior of her ovipositor
became visible, and an egg was deposited. The egg was usually placed
between the plant hairs close to the surface, and adhered tightly to the
plant. Rain or dew did not remove the eggs, and they were nearly
impossible to remove from the leaf with a camel's hair brush" (Greene et
al. 1973, p. 1115).

- 36 -
Oviposition occurred throughout scotophase but was most common from
0.5 h after sunset until 0200. A peak in egg laying occurred
2-4 h after sunset. Temperature, humidity, and dew were reported to
affect ovipositional activity. Oviposition increased as temperature
decreased and humidity increased. Also, oviposition seemed to decrease
as dew accumulated, except for the first night. Dew formed from 2200 to
2400 (Greene et al. 1973).
With 20 pairs of colony adults in each of three cages, Leppla
(1976) found that egg deposition did not occur during the first 3 days
after emergence, peaked on day 5, and declined from day 6 until day 18
when oviposition stopped. Relative humidity (RH) had a critical effect
on colony performance. A RH of 85 5%, at least during scotophase, was
required for adequate mating. Without adequate conditions for mating,
few viable eggs were produced. The placement and vertical distribution
of VBC eggs on soybean (cultivar UFV-1) were reported by Ferreira and
Panizzi (1978). Eggs were found mainly on the lower two-thirds of
plants and most were on pods (59%), some on stems (37%), and a few on
leaves (4%).
Moscardi et al. (1981c) investigated the effects of temperature on
oviposition, egg hatch, and adult longevity, under constant and variable
temperatures. Mean total oviposition was highest at 26.7C (842.2
26.1 eggs) and steadily decreased in either direction from 26.7C to the
lowest mean at 32.2C (310.0 14.7 eggs). At temperatures < 18.2C or
> 32.2C, adult survival and reproductive capacity were retarded
significantly. Mean percent egg hatch was (1) highest at 26.7C, (2)
not significantly different for 26.7, 29.4, or 32.2C, and (3) lowest at
21.1C. Mean longevity for mated females was longest at 21.1C (24.8
1.0 days) and steadily decreased to the shortest longevity at 32.2C

- 37
(11.2 0.6 days). At 26.7C unmated females lived longer (22.8 0.8
days) than mated females (18.0 1.0 days). As temperature increased
from 21.1 to 32.2C, mated females laid the majority of their eggs at
progressively earlier ages. At all temperatures, 50% of all oviposition
occurred within four to nine days after emergence and steadily declined
thereafter.
Females reared from larvae maintained on different soybean
phenological stages exhibited variation in mean total oviposition, mean
percent egg hatch, mean longevity and Rq (Moscardi et al. 1981b). "Mean
oviposition-rates ranged from 963.4 to 515.0 eggs/female when larvae fed
on early vegetative and senescent leaves, respectively. Average daily-
oviposition peaked ca. 4 days after adult emergence, decreased sharply
to day 10, and remained at a low level until adult mortality. Mean
daily egg-hatch decreased with female age, but female longevity was not
affected significantly" (Moscardi et al. 1981b, p. 113).
Using a pivoted-stick actograph, Wales (1983) confirmed that mated
females lay most of their eggs early in life. Unmated females delayed
oviposition until very late in life. The hourly distribution for lab
mated and wild mated females, ages one to nine days old, indicated that
most eggs were laid in the first four hours of scotophase, but that
oviposition occurred all night.
Feeding
Not much is known about adult feeding in the field. Hinds (1930)
reported adults fed on the nectar of a Crotalaria sp. Greene et al.
(1973, p. 1115) observed feeding during all hours of scotophase, "with
peak activity from sundown to after 12:00 midnight [sic]." Primarily
females, but also some males, fed on crushed grapes from sunset until
0230 when observations stopped. Adults fed at the seed heads of

- 38 -
bahiagrass, Paspalum notatum Flugge, throughout scotophase but most
abundantly at sunset. The food source on the bahiagrass seed heads was
not determined. Moths were observed to feed on dew droplets on soybean
and on water in a cup. The chemical content of the dew and water was
not determined.
Various honey solutions have been used for adult food in numerous
laboratory studies (see Leppla 1976, Leppla et al. 1979, Johnson et al.
1981, Moscardi et al. 1981b, Moscardi et al. 1981c, Oliveira 1981, Wales
1983). The effect of variation in adult diet on oviposition and
longevity was explored by Wales (1983). "Moths fed 5% or 10% honey
solution had mean longevities of 19.6 and 16.4 days and mean fecundities
of 846.1 and 866.2 eggs/female, respectively. Water-fed females lived
9.3 days and produced 212.7 eggs, and unfed females lived 5.7 days and
produced 41.6 eggs/female" (Wales 1983, p. ix).
Predators
Little is known about predators of adult VBC. Watson (1915, 1916c)
reported dragonflies as predators but listed no common or scientific
names. Neal (1974) reported two predatory species, the green jacket
dragonfly, Erythemis simplicicollis (Say), and the striped earwig,
Labidura riparia (Pallas).
Research Goals
The present study on the behavioral ecology of adult VBC was
initiated as part of a project to explore the movement of adult VBC into
a soybean field (review pp. 27-28). To examine this movement, a
mathematical relationship had to be established between adult and egg
densities in a soybean field (see Chapter VI). To obtain estimates of
adult and egg densities (see Chapters IV and V), and to establish a
relationship between these estimates, a number of questions about adult

- 39 -
behavior in the field had to be resolved: (1) Did flight activity vary
through time? (2) Did oviposition occurrence and frequency vary through
time? (3) What environmental factors affected flight activity and
oviposition? and (4) What environmental factors affected the movement
of adults in and out of soybean? In addressing these questions,
additional behavioral observations were recorded and are reported below.
Materials and Methods
From 1980-1982,* field observations were conducted at the
University of Florida's Green Acres Research Farm, located 22.5 km west
of Gainesville, FL (Alachua County). This farm covers ca. 93 ha, and
consists of crop fields, fallow fields, and wooded areas. The principal
observation site was a 1 ha soybean field (cv. Bragg), but observations
were made also at other sites on the farm. Agronomic practices and
soybean phenological stages of each soybean field in all three years are
listed in Appendix A.
All behavioral observations were made by remaining stationary or
walking slowly, and were recorded verbally on a hand-held Panasonic
TM
Microcassette Recorder, Model RN-001D. The time of each observation
£
was recorded to the nearest minute. A six-volt Everready Freedom
TM
Light (i.e., a head lamp) was used for nocturnal observations; the
lighting fixture was covered with a section of Ziptone color sheet,
Vermillion Hue #2545. Adult VBC were sexed with leg-scale morphological
differences (see Anonymous 1974 and Appendix B), but were not aged.
Another moth, Mocis latipes Guenee (Lepidoptera: Noctuidae),
*During the summer of 1983, a few records of adult feeding and spider
predation were obtained at various localities. These records are
considered ancillary to the text of this chapter but were added where
appropriate and with the necessary detail.

- 40 -
occurred at the study site and looked similar to VBC. Differences
between adults of these two species are discussed in Appendix B.
Temperature and humidity were monitored continuously with a
hygrothermograph (Weather Measure Corporation Model No. H311). Also,
£
temperature was monitored hourly with an Esterline Angus PD2064
Microprocessor. Rainfall was recorded continuously by a Universal
Recording Rain Gage (12" chart with dual springs, Belfort Instrument
Co.). Sunset and sunrise times were obtained from Oliver* (personal
communication). Phase and temporal occurrence of the moon were obtained
from the Astronomical Almanac (Smith and Smith 1981, and Vohden and
Smith 1982) and were noted with visual observation in the field. In
1981 and 1982, wind speed was recorded at 15 min intervals with a gill,
3-cup, anemometer (Model 12102, R. M. Young Co.). In 1981, wind
direction was recorded at 15 min intervals with a gill microvane (Model
12302, R. M. Young Co.).
Quantitative Technique
The temporal occurrence and frequency of several adult activities
(oviposition, mating, and feeding) during scotophase were examined
quantitatively. Scotophase was partitioned into hourly increments after
sunset, with the hours numbered consecutively from 1 (sunset) to 12
(sunrise). For an activity on a particular night, the amount of
observation time and the number of observations were segregated
according to their hour of occurrence. Observations were weighted with
respect to observation time to correct for a time bias (i.e., the number
of observations were divided by the amount of observation time). No
*J. P. Oliver, Associate Professor of Astronomy, Department of
Astronomy, University of Florida, Gainesville, FL 32611.

- 41
significant differences occurred between years according to the
Kruskal-Wallis Test (a = .05). Therefore, weighted observations from
different years, months, and nights were grouped by hour of occurrence.
The sample mean of the weighted observations of each hour was
calculated. These sample means were normalized, multiplied by 100 to
yield percentages, and plotted against their respective hour.
Sample means were normalized by totaling the 12 hourly sample means
and dividing each sample mean by the total. Normalization of the sample
means allowed for proportionality among the means. Percent normalized
sample means were used for ease of discussion, as opposed to the use of
normalized sample means. The standard error of each sample mean was
determined, normalized and multiplied by 100. A detailed explanation of
the quantitative technique and the raw data are presented in Appendix C.
Assumptions
To analyze the behavioral observations quantitatively, several
assumptions were made: (1) an activity had an equal chance of being
observed whether I was stationary or walking, (2) adult age did not
affect the temporal or spatial occurrence of adult activities (i.e.,
observed adults were not aged), and (3) the temporal length of
scotophase (sunset to sunrise) was the same for all nights.
Results and Discussion
Approximately 355 h were spent observing adult behavior (Table
3.1). The majority of the time (90%) was spent in the field during
July, August, and September, and more time occurred during photophase
(201 h and 19 min) than during scotophase (153 h and 13 min).
The first adult sightings in 1981 and 1982 occurred during
photophase on 3 August and 19 July, respectively. In both years, the
first adults were found in areas of the field where the
canopy was

Table 3.1. Amount of time dedicated to behavioral observation of adult velvetbean caterpillar in a 1
ha soybean field at
the Green
Acres
Research
Farm, Alachua
County,
FL, from
1980-82.
Month
Scotophase
Time
Observation
(min)
Photophase^
Time
Observation
(min)
Total
Observation
Time (min)
1980C
1981
1982
Total
1980C
1981
1982
Total
June
0
180
359
539
0
90
630
720
1259
July
0
609
1080
1689
0
876
3481
4357
6046
Aug.
180
2159
1158
3497
0
2489
1735
4224
7721
Sept.
0
1717
1401
3118
10
335
1894
2239
5357
Oct.
0
0
350
350
0
30
509
539
889
Total
(min)
9193
12079
21272
Total
(hr/min)
153/13
201/19
354/32
Scotophase was sunset to sunrise.
kphotophase was sunrise to sunset,
c
In 1980, most of the observation times were not recorded.

- 43 -
almost or completely closed. The initial occurrence of adults in the
field may be related to microclimatic differences in moisture (see
Chapter IV). During the field season, adults were not observed in areas
of the field where the canopy was open. Movement of moths out of the
field in September and October coincided with the senescing of the
soybean and movement into stands of wild hairy indigo (Indigofera
hirsuta L.). During photophase, moths demonstrated a definite
preference for residing in the field, as opposed to the edge of the
field. Occasionally, adults were found at the field edge in thick
clumps of grass or weeds but, regardless of the location, moths were
found always on the ground or close to the ground on plants or dead
plant-matter. Areas of high moisture (see Chapter IV), low light, and
negligible wind appeared to be preferred. Moths were not observed in
areas that were opened and exposed to sunlight and wind.
Flight Activity
Flight activity was assessed qualitatively with visual
observations. When approached (or flushed) during photophase, adults
flew ca. 1-10 m, landed on the ground or on low vegetation, and became
immobile. Flight speed and pattern varied from slow to fast and
flutter-like to darting, respectively. Flight direction was highly
variable. Adults flew between rows, across rows, within the canopy,
over the canopy, and demonstrated numerous combinations of these
directions. Flight was controlled, and moths did not hit leaves or
other objects, contrary to the report of Greene et al. (1973). Aside
from flushed adults, flight activity during the day was very uncommon
but consisted of flight just above the canopy and flight while feeding.
See the section below entitled "Feeding" for a discussion of in-flight
feeding during the day. With regard to flight just above the canopy,

- 44 -
one or more moths were observed in this activity on four different days.
Flight activity occurred within ca. 15 min of sunset and flight distance
varied from ca. 1 m to greater than 100 m; after 100 m adults were too
difficult to observe. Flight speed and pattern usually were fast and
darting, respectively.
During scotophase, flight activity was highly evident and
temporally variable. During the first ca. 15 min after sunset, flight
activity usually was negligible with ca. 0 to 20 flights. Between ca.
15 and 30 min after sunset, flight activity appeared to double but, on
one night in September of 1980 (no record of date), several hundred
adults were observed flying at this time. From ca. .5 to 2.5 h after
sunset, flight activity peaked and then slowly decreased from ca. 2.5 to
4.5 h after sunset. Between 4.5 h post-sunset and sunrise, flight
activity was minimal and decreased steadily to zero flights at sunrise.
Flight was utilized for oviposition, mating, feeding and,
presumably, general dispersal. Flight distance varied from ca. .01 m to
greater than 100 m, but after 100 m flying adults were not observable.
Flight speed and pattern varied from slow to fast and flutter-like to
darting, respectively.
The most striking flight activity consisted of ca. 3 to 10 adults
of unknown sex that appeared to fly in formation. Five of these
3
formations were observed. Each occupied ca. 1 m in volume, occurred at
or below the top of the soybean canopy, moved in one direction across or
between rows, and varied in speed from moderately fast to fast. Flight
paths of individual moths were highly convoluted. Formations looked
like a writhing group of moths, lasted from ca. 7 to 30 sec and covered
from ca. .03 to 10 m. The nature of these formations is obscure but may
be involved with mating.

- 45 -
Flight activity did not appear to be affected by moon phase,
moonlight, humidity, dew, wind speed or wind direction. During light
rainfall, flight activity was unaffected but, during intermediate to
severe rainfall, flight activity was reduced. If moderate or severe
rainfall stopped between sunset and ca. 4.5 h post-sunset, flight
activity resumed. If rain stopped after ca. 4.5 h post-sunset, flight
activity was negligible.
Flight activity was affected by temperature. On 19 September 1981,
ambient temperature decreased from 17.7C at 2000 to 11.9C at 2230,
when flight activity stopped. Twenty-three adults (11 males and 12
females) were picked up or touched. None of these moths were able to
fly but some slowly flapped their wings once or twice. Thus, 11.9C was
designated as the lower threshold-temperature for flight activity.
In general, present observations of flight activity agree with
previous observations of feral adults (see Watson 1915, 1916a, 1916b,
Douglas 1930, Ellisor 1942, Greene et al. 1973, Gutierrez and Pulido
1978), but do not agree with observations of colony adults (see Leppla
et al. 1979, Wales 1983). Leppla et al. (1979) found a high frequency
of flight during photophase of the first six days for paired adults and
Wales (1983) was unable to resolve hourly patterns of flight frequency
during scotophase. Results from both studies contrast sharply with
present findings. Differences among the present study and those of
Leppla et al. (1979), and Wales (1983) may be an artifact of adult
colonization. Colonized adults apparently behave differently than wild
adults.
Mating
Of the five stages in the courtship sequence reported by Greene et
al. (1973), four were observed in the field: pheromone release, male

- 46 -
response, mounting by the male, and separation. Sperm transfer was not
observed. Greene et al. (1973) must have assumed sperm transfer took
place between coupled moths because they did not present their
techniques for observation of this internal process. Greene et al.
(1973) noted that calling females pointed their abdominal tip either
dorsally or ventrally, and Johnson et al. (1981) noted wing fanning
followed immediately by dorsal elevation of the abdominal tip. In
present observations, "calling" females were observed rarely with an
arched abdomen (ventrally or dorsally) or a protruding pheromone-gland.
In "calling," a female positioned her feet on a plant surface; wings
were extended horizontally, vibrated, and flattened to the substrate.
Wing vibration was very rapid, lasted ca. 3-10 secs, and was difficult
to observe because of the high frequency of the vibrations and the small
vertical pitch of the wings (ca. 1-2). Typically, feral females
appeared to release pheromone without abdominal arching or displaying a
pheromone gland. The discrepancy among present observations and those
of Johnson et al. (1981) and Greene et al. (1973) is unclear but may be
due to observer interference. When releasing pheromone, moths appeared
"agitated" by my light and would rapidly withdraw their pheromone gland
(if everted).
During courtship, a male approached a calling female by flying in a
zigzag path. This zigzag flight-path was essentially horizontal,
although the male gradually descended toward the female. Male flight-
speed was moderate, wing beat was flutter-like, and the male hovered
briefly over the female before mounting her. The time from mounting to
opposing position lasted ca. 2-10 sec. A similar time (x = 5 sec) was
reported by Greene et al. (1973). Opposing position was obtained when
the male swung to the left, and downward, 180; swinging may occur to

- 47
the right but was never observed. Following the swing manuver, both
adults essentially were in the same horizontal plane, heads were pointed
in opposite directions, and their abdominal ends were connected caudally
(see Fig. 3.1). Typically, in opposing position, the female faced
skyward and the male faced earthward. Males were observed with their
feet on plant substrate or dangling in air.
Couples were immobile during the opposing position. If touched,
couples remained immobile, walked less than 5 cm, or fell to the ground
or a plant structure. In falling, adults slowly fluttered their wings.
Wing movement stopped upon landing and adults became immobile. Upon
separation, males flew away within ca. 5 min but females remained at the
copulation site for a longer but undetermined length of time. Greene et
al. (1973) noted a similar scenario of immobility during copulation and
of separation activities. Typically, coupled adults were not disturbed
by other adults but on two separate occasions an adult male flew into
and bumped a mating pair. After several bumps the males flew away.
Perhaps these females were still emitting pheromone.
In 1981, 7 pairs of adults were timed for length of opposing
position. All pairs were found on soybean within one hour after sunset,
and all pairs had coupled prior to their location (except for one pair).
These adults may have been coupled for an hour prior to their location,
but mating was uncommon in the first .5 h after sunset and was never
observed during photophase (see below). Opposing position was
maintained for 2 h 10 min 32 min (x SD), and this time closely
agrees with that reported by Greene et al. (1973).
Adults in opposing position were observed 157 times, with 135 on
soybean, 11 on beggarweed [Desmodium tortuosum (Sw.) DC.], 9 on hairy
indigo (Indigofera hirsuta L.), and 2 on bahiagrass (Paspalum notatum

Figure 3.1. Mating pair of adult velvetbean caterpillar on a soybean leaflet. Adults
are in opposing position, with the male facing downward, or earthward.
Photograph taken at Green Acres Research Farm, University of Florida,
Alachua County, FL, 19 September 1982.

- 49 -
Flugge). On soybean and beggarweed, each pair was found on a leaflet.
On hairy indigo, one of the opposing pairs was observed on developing
seeds. The other eight pairs were found with each pair on several
leaflets; a hairy indigo leaflet is smaller than a VBC adult. On
bahiagrass, each opposing pair was observed on a raceme. Of the records
that were kept of adult position on leaflets, the following can be
noted: (1) for soybean, 29 pairs were on the bottom and 2 pairs on the
top, (2) for beggarweed, 4 pairs were on the bottom and 5 pairs on the
top, and (3) for hairy indigo, 1 pair was on the bottom and 1 pair on
the top. No definite preference between leaflet top and bottom was
noted for beggarweed or hairy indigo. A definite preference for the
bottom of a soybean leaflet was noted. The relevance of this preference
is unknown, but it may be a behavioral trait to avoid predation. Moths
mating on the bottom of a leaflet are more difficult to see than moths
on the top of a leaflet. As moths are docile and immobile during
mating, adults on the top of a leaflet may be seen and preyed upon more
readily by predators.
Mating occurred exclusively on legume plants, except for 2 pairs in
1980 that mated on bahiagrass at the field edge. Of the 157 observed-
pairs of coupled adults, 135 pairs (ca. 86%) mated on soybean, 11 pairs
(ca. 7%) mated on beggarweed, and 9 pairs (ca. 6%) mated on hairy
indigo. All matings on beggarweed and hairy indigo were observed in
1982, except for one pair on beggarweed in 1981.
A shift in mating site appeared to occur in late September, 1982.
Limited observations in late September of 1980 and 1981 prohibited the
disclosure of such a shift during those years. In 1982, the shift
appeared to be from soybean to hairy indigo. Mating occurred on soybean

- 50 -
in August and September and on hairy indigo in late September in a
fallow border area (see Appendix C, Table C.3). The border area was
composed predominately of hairy indigo plants that were tall (ca. 1.5 m)
and exhibited lush, thick vegetative growth. The shift from soybean to
hairy indigo may have occurred for three reasons. First, a high
moisture level is required for VBC mating (Leppla 1976). The hairy
indigo appeared to maintain a high moisture microclimate, while soybean
was senescing. Many leaves had fallen from the soybean and moisture
around the plants was decreasing (see Chapter IV). Secondly, hairy
indigo was an ovipositional site (see below). Soybean received a low
complement of VBC eggs in late September (see Chapter V). Thirdly,
female VBC may have been attracted to the height of the hairy indigo
plants. VBC tended to mate on soybean at a height of ca. .8 m or
higher. "Calling" at this height may have increased mating success
through better pheromone dispersal.
Mating was observed only during scotophase, between sunset and
sunrise, from 1980-82 (see Appendix C, Table C3). Mating may have
occurred during photophase (sunrise to sunset), but this occurrence is
doubtful, except for times close to sunset. Low levels of moisture at
the canopy top during photophase should inhibit mating during photophase
(see Leppla 1976 and Chapter IV). Also, predation of mating moths
should be higher during photophase, as moths would be visually exposed
and immobile.
Based on the percent-normalized sample means of the weighted
observations, 79.25% of all mating occurred within the first four hours
after sunset [see Fig. 3.2(A) and Appendix C, Table C.4]. Greene et al.

PERCENT- NORMALIZED SAMPLE MEAN
HOUR AFTER SUNSET
Figure 3.2. The percent-normalized sample mean ( SE) of each post-sunset hour for activities of adult
velvetbean caterpillars: (A) mating, (B) oviposition, (C) feeding, males in aggregations,
(D) feeding, males not in aggregations, (E) feeding, all males, (F) feeding, females, (G)
feeding, unsexed adults, (H) feeding, males (all), females, and unsexed adults, and (I)
feeding, males (not in aggregations), females, and unsexed adults. Observations were made
from 1980-82 at the Green Acres Research Farm, Alachua County, FL, in a 1 ha soybean field.
i
U)
I

- 52 -
(1973) obtained similar results and found that 66%* of all mating
occurred over the same time period. Both of our results contrast
sharply with those of Leppla (1976), where 81%** of all mating for
colony adults occurred in hours 6-10 of scotophase.
The difference in Leppla's (1976) results from the results in this
study and from Greene et al. (1973) may be related to (1) colony
artifact, (2) temperature and predation, (3) moisture, or (4)
reproductive isolation. Colony adults may mate at a different time from
feral adults due to colonization. As noted above, colony adults do
behave differently than feral adults with regard to the temporal
occurrence of flight. With regard to temperature and predation, colony
adults are maintained at a constant temperature and are not exposed to
predation. Wild adults are exposed to variable and cyclic temperatures
(See NOAA 1982) and should be vulnerable to predation when mating at
certain times, as moths are highly visible and very docile. If mating
is temperature-dependent, more time will be required to complete mating
as temperature decreases during the night. Wild moths that mate in
early scotophase will complete mating before sunrise. Wild moths that
mate in late scotophase probably will not complete mating before sunrise
and will be exposed visually to predators. In a colony with constant
temperature and a lack of predation, females may "assess" the
temperature/predator risk and mate during late scotophase. Mating by
colony adults in late scotophase may favor the completion of a more
beneficial activity during early scotophase (e.g., oviposition). Also,
*Percentage value determined with calculations of data in Table 1 of
Greene et al. (1973, p. 1114).
**Percentage value determined with calculations of data in Fig. 3 of
Leppla (1976, p. 47).

52 -
(1973) obtained similar results and found that 66%* of all mating
occurred over the same time period. Both of our results contrast
sharply with those of Leppla (1976), where 81%** of all mating for
colony adults occurred in hours 6-10 of scotophase.
The difference in Leppla's (1976) results from the results in this
study and from Greene et al. (1973) may be related to (1) colony
artifact, (2) temperature and predation, (3) moisture, or (4)
reproductive isolation. Colony adults may mate at a different time from
feral adults due to colonization. As noted above, colony adults do
behave differently than feral adults with regard to the temporal
occurrence of flight. With regard to temperature and predation, colony
adults are maintained at a constant temperature and are not exposed to
predation. Wild adults are exposed to variable and cyclic temperatures
(See NOAA 1982) and should be vulnerable to predation when mating at
certain times, as moths are highly visible and very docile. If mating
is temperature-dependent, more time will be required to complete mating
as temperature decreases during the night. Wild moths that mate in
early scotophase will complete mating before sunrise. Wild moths that
mate in late scotophase probably will not complete mating before sunrise
and will be exposed visually to predators. In a colony with constant
temperature and a lack of predation, females may "assess" the
temperature/predator risk and mate during late scotophase. Mating by
colony adults in late scotophase may favor the completion of a more
beneficial activity during early scotophase (e.g., oviposition). Also,
*Percentage value determined with calculations of data in Table 1 of
Greene et al. (1973, p. 1114).
**Percentage value determined with calculations of data in Fig. 3 of
Leppla (1976, p. 47).

- 54 -
The temporal occurrence of oviposition in the field may be due to
the selective pressures of egg predators and parasites. Eggs are mint
green when laid (see below and Chapter V) and are easy to see on
soybean. As eggs age, they develop a speckling pattern (see below and
Chapter V) and are extremely difficult to see on a plant (i.e., speckled
eggs are cryptic). The occurrence of this speckling pattern is
temperature dependent (see Chapter V). Eggs laid during early
scotophase speckle at or just after sunrise (see Chapter V) and probably
are difficult for predators to see. Eggs laid during late scotophase
are still mint green after sunrise, are easy to see, and probably are
exposed to more predation. Females that oviposit in early scotophase
should demonstrate a higher reproductive fitness over females that lay
eggs in late scotophase.
Oviposition was difficult to observe. Only 121 sightings were made
during the 153 h 13 min of scotophase observation (see Appendix C, Table
C.5). Female density may have affected the viewing of oviposition. In
1982, an estimate of female absolute density in the field was obtained
at weekly intervals with an adult trap-cage (Table 3.2, see also Chapter
IV). Estimates of female density were highest from August 26 to
September 23. Interestingly, 61 of 73 ovipositional sightings (81%)
were made at this time with an investment of only 41% of total
observation time (1764 of 4348 min)(see Appendix C, Table C.5).
Obviously, a productive time period to view oviposition occurred when
total female density was greater than ca. 764 individuals.
Concentration of more observation time during this time period may have
generated more sightings.
Flight speed of ovipositing females was moderate and wing beat was
flutter-like. The distance between ovipositional sites varied from ca.

55
Table 3.2. Estimates of the absolute density of adult females
of the velvetbean caterpillar in a soybean field.
Density was determined with an adult trap-cage
(see Chapter IV) in 1982 at the Green Acres
Research Farm, Alachua County, FL.
Absolute Density
Date of Adult Females
(number/.87 ha)
July 15
0
July 22
0
July 29
0
August 5
416.8
August 12
347.3
August 19
416.8
August 26
1806.2
September
2
2570.4
September
9
2292.5
September
16
694.7
September
23
764.1
September
30
208.4
October 7
347.3
October 14
416.8

- 56 -
.10 to 1.25 m, based on visual estimates. When ovipositing on a
leaflet, a female (1) landed on the leaflet, (2) moved her abdominal tip
back and forth across the leaflet surface and sometimes walked at the
same time, (3) positioned her abdominal tip against a leaflet vein, (4)
arched her abdomen with the abdominal tip directed downward, (5) pressed
her abdominal tip against the leaflet surface and the vein, exposing the
conjunctiva anterior of the ovipositor, and (6) laid an egg.
Oviposition on plant structures other than leaflets followed the same
procedure, with the obvious exception that eggs were not laid on leaflet
veins. Time required to lay an egg varied from ca. 2 to 30 sec, and
eggs were glued to the surface and trichomes of the plant structure.
Twenty-four hours later, eggs were impossible to remove without
crushing. Contrary to present observations, Greene et al. (1973)
indicated that eggs were nearly impossible to remove immediately after
oviposition and that oviposition occurred in 2-60 sec, twice as much
time as observed here.
All eggs were laid singly on leaflets, pulvini, or petioles, except
for 19 September 1981 (ca. 2000) when one female laid seven eggs on a
leaflet and another female attempted to lay three eggs on a leaflet.
Low ambient temperature (17.7C) affected the behavior of these two
females. While ovipositing, both females continuously vibrated their
wings, a previously unobserved ovipositional activity. Presumably, wing
vibration allowed for ovipositonal activity at this temperature; wing
vibration without flight in Lepidoptera allows for activities at
suboptimal temperatures (Chapman 1971). Both females vibrated their
wings for ca. 1 min before flying to another leaflet. Their flight
speed was very slow and wing beat was flap-like.

- 57 -
At 2230 on 19 September 1981, all flight and oviposition stopped
when the temperature fell to 11.9C. Twelve females were picked-up or
touched and none were able to fly. Most remained very rigid and did not
move, but a few flapped their wings once or twice, or took a few steps.
Evidently, 11.9C is near the lower threshold for oviposition. Overall,
these observations indicate that temperature affects egg dispersion and
deposition.
Greene et al. (1973) found that ovipositional activity increased
with decreasing temperature. Neither my results nor those of Moscardi
et al. (1981c) agree with the findings of Greene et al. (1973).
Moscardi et al. (1981c) found that mean total oviposition varied
significantly with temperature (Table 3.3). In a linear regression of
their data and the assumed ovipositional threshold of 11.9C* (see Fig.
3.3), a correlation (r2 = .75, n = 74) was found between total
oviposition per female and temperature with the model:
y = -694.97 + 58.40(x),
where y = total oviposition per female, and
x = temperature between 11.9 and 26.7C.
Slope and intercept parameters were determined with observations and not
mean estimates, but mean estimates are shown in Fig. 3.3 for ease of
view. The regression line was forced through the x intercept at 11.9C.
No other weather factors besides photophase and temperature were
observed visually to affect oviposition (i.e., humidity, rainfall,
moonlight, wind speed and wind direction). Greene et al. (1973) found
*Data used in the regression are listed in Appendix C, Table C.7. Data
of Moscardi et al. (1981c) were stored on computer cards in Building
175, Insect Population Dynamics Laboratory, at the University of
Florida, Gainesville, FL, at the time that this regression model
calculated.
was

- 58 -
Table 3.3. Mean total oviposition by adult females of the
velvetbean caterpillar reared from eggs at constant
temperatures, 14L:10D photoperiod, and RH > 80%
(modified from Moscardi et al. 1981c).
Temperature Number of
(C) Mated Females
Mean
Total-Eggs/Female ( SE)a
21.1
19
482.8
+
21.3C
23.9
29
732.3
+
22.9B
26.7
25
842.2
+
26.1A
29.4
15
713.5
+
28.IB
32.2
19
310.0

14.7D
^eans followed by the same letter are not significantly
different according to Duncan's multiple range test (a = .05).

- 59 -
10 13 16 19 22 25 28
TEMPERATURE (C)
Figure 3.3. Linear relationship between total eggs per velvetbean
caterpillar adult female and temperature. Regression line
is y = -694.97 + 58.40(x), (r2 = .75, n = 74), where y =
total oviposition per female, and x = temperature between
11.9 and 26.7C. Mean estimates are shown in the figure
for ease of view. Data are from Moscardi et al. (1981c),
while the assumed threshold temperature is from field
observations at Green Acres Research Farm, Alachua County,
FL.

60 -
oviposition was more common as RH increased and less common as dew
formed during scotophase. Current observations do not support the
findings of Greene et al. (1973) for the following reasons: (1) RH
during the first hour after sunset was typically lower than all other
hours during scotophase (see NOAA 1982), (2) the. highest percentage of
oviposition [29%, see Fig. 3.2(B)] occurred during the first hour
post-sunset, and (3) females were observed frequently to oviposit after
dew set.
Fifty-four of the 121 ovipositional sites were searched for eggs;
at 20 sites eggs were found, at 34 sites no eggs were found, and no
search was made at 67 sites. Greene et al. (1973) noted also that
females exhibit ovipositional behavior without leaving an egg. The
nature of this behavior is obscure, but at least three possible
explanations exist: (1) eggs may not adhere to substrate, (2) females
may lack a proper ovipositional cue, and (3) females might leave egg
kairomones that may "confuse" egg predators and parasites.
Of the twenty sightings at which an egg was laid, all eggs were
light green in color. Twenty-four hours later, all eggs had numerous
small reddish-brown speckles over a light-green background color. These
small reddish-brown speckles indicated egg viability (see Chapter V).
Oviposition was observed on soybean 48 times (1981) and 72 times
(1982), and on hairy indigo one time (1982). On soybean, all
ovipositions occurred on leaflets except for one sighting each on a
pulvinus and on a petiole. Fourteen records were kept of egg placement
on leaflets. Thirteen eggs were placed by main veins and one egg was
placed by a secondary vein. All eggs were glued to the plant substrate
and to closely associated trichomes. Trichome density on the leaflets

- 61
was highest along the main vein and less dense along the secondary
veins. Pulvini were covered in a thick "carpet" of trichomes and
petioles had trichomes that occurred in longitudinal rows. Both Hinds
(1930) and Ellisor (1942) noted an ovipositional preference for areas of
high trichome density.
Feeding
More individuals were observed feeding than for any other activity.
A total of 458 individuals were sighted: 268 males, 129 females, and 61
unsexed adults (Table 3.4). Unsexed adults flew away before a positive
sexual identification could be made. Feeding occurred predominately at
night, when 448 of the moths (or 98%) were observed (Table 3.4).
When feeding, the proboscis was extended, touched the food source,
and was maneuvered across the food source surface. Except for flowers,
all moths were observed to feed on moist surfaces. This moisture was
either rain water, dew, plant-guttated water, or plant exudates. When
feeding at a flower, a moth would probe the flower with its proboscis.
The attainment of nectar or pollen was not assessed. No adults were
observed to feed at soybean flowers and none of the food sources were
chemically analyzed.
Overall, feeding was the easiest behavioral activity to observe.
At night, adults were easy to approach and observe. Individuals
"rested" on an available substrate while feeding, as opposed to flying.
During the day, adults were more difficult to approach and observe. On
six occasions, moths were observed feeding at flowers (Table 3.5).
These moths hovered in flight while feeding, were in the open, and were
easy to see. When approached from ca. 1.5 m moths stopped feeding, flew
a short distance and "hid" among weeds. Apparently, adults can see very

62 -
Table 3.4. Number of unsexed, male, and female adults
of the velvetbean caterpillar observed
feeding in a soybean field at Green Acres
Research Farm, Alachua County, FL, in
1980-82.
Temporal
Occurrence
UnsexedC
Adults
Male
Female
Total
Photophase
8
1
1
10
Scotophase'3
53
267
128
448
Total
61
268
129
458
Photophase = sunrise to sunset.
^Scotophase = sunset to sunrise,
c
Unsexed adults flew out of sight before sexual
identification could be made.

Table 3.5. Observational records of feeding by adult velvetbean caterpillar during photophase at the Green
Acres Research Farm, Alachua County, FL, from 1980-83.
Date
Time of
Sunset
Time of
Observation
Time Before
Sunset (h/min)
Number of
Adults
Adult Sex3
Food Source*5
19 September 1980
1930
1900
0/30
2
Adult
Horse Mint
20 September 1980
1928
1900
0/28
2
Adult
Horse Mint
24 September 1982
1923
1900
0/23
2
Adult
Hairy Indigo
02 October 1982
1914
1515
3/59
1
Female
Hairy Indigo
2
Adult
Hairy Indigo
02 October 1982
1914
1535
3/39
1
Male
Hairy Indigo
08 November 1983C
1739
1730
0/09
2
Female
Common Beggar Tick
Sexually unidentified moths are listed as adult.
**The food source was always at a flower.
Horse Mint is Monarda punctata L.
Hairy Indigo is Indigofera hirsuta L.
Common Beggar Tick is Bidens alba (L.) DC.
c
Observed on the campus of the University of Florida, Gainesville, FL.

64 -
well in daylight or detect human presence. Why these moths stopped
feeding and flew is unknown.
A definite preference for feeding sites at the edge of the field (
ca. 2 m) was exhibited, where ca. 57% (261 of 458 adults) of all feeding
was observed. Of the 197 observations in the field, 163 were of adult
males at human-altered feeding sites. Re-examination of the data
without these human-altered sites reveals that ca. 88% (261 of 295
adults) of all feeding occurred at the edge of the field. Due to the
strong bias of feeding at field-edge sites, and because most observation
time was spent in the field and not at the field edge, results on the
temporal occurrence of feeding should be viewed with caution. Proper
assessment of the temporal occurrence of feeding should be examined with
a separate study.
Adults fed at numerous sites (Tables 3.6-3.8). The most striking
feature about site selection was the dichotomy between male and female
sites. Although males and females shared common sites (Table 3.7), some
sites were visited strictly by males (Table 3.8). At these sites, males
were observed usually in aggregations of two or more individuals (see
Figs. 3.4 and 3.5). Of the 179 males at these sites, 159 were found in
aggregates, and 121 of these aggregated males were on aerial and sweep
nets (bags and poles). These nets were used frequently in the field
(soybean and fallow areas) to collect arthropods, were stained heavily
with arthropod and plant substances, and were coated with human sweat
and oil. The Saran Screens, additional sites of male aggregations, were
handled also by people and coated with human sweat and oil. Male
aggregations were observed only at human-altered sites and not at
naturally occurring sites. When feeding in aggregates, males were

a
Table 3.6. Number of unsexed adults of the velvetbean caterpillar observed feeding in a soybean
field at Green Acres Research Farm, Alachua County, FL, in 1980-82. Description of food
site and host provided.
No. of Unsexed^
Adults Feeding
FoodC
Site
Food Host
Common Name
Scientific Name
Family
4
Flower
Horse Mint
Monarda puntata L.
Labiatae
43
Raceme
Bahiagrass
Paspalum notatum Flugge
Gramineae
2
Raceme
Unknown Grass

Gramineae
1
Flower, Unopened
Florida Pusley
Richardia scabra L.
Rubiaceae
6
Flower, Outside
Hairy Indigo
Indigofera hirsuta L.
Leguminosae
5
Flower
Hairy Indigo
Indigofera hirsuta L.
Leguminosae
Unsexed adults flew out of sight before a positive sexual identification could be made.
bTotal = 61.
c
Adults fed at the surfaces of plant structures or in flowers.

Table 3.7. Number of male and female adults of the velvetbean caterpillar feeding in
a soybean field at Green Acres Research Farm, Alachua County, FL, from
1980-82. Description of food site and host provided.
No. of3
Males
Feeding
No. ofb
Females
Feeding
Food SiteC
Food Host
Common Name
Scientific Name
Family
i
i
Seed
Slender Amaranth
Amaranthus vlrldis L.
Amaranthaceae
50
84
Raceme
Bahlagrass
Paspalum notatum Flugge
Gramineae
12
11
Leaflet
Soybean
Glycine max (L.) Merr.
Leguminosae
3
2
Leaflet Dead
Soybean
Glycine max (L.) Merr.
Leguminosae
0
1
Stem, Dead
Unknown Plant**


3
2
Leaflet, Dead
Beggarweed
Desmodlum tortuosum (Sw.) DC.
Leguminosae
2
2
Roots, Stems, Dead
Beggarweed
Desmodlura tortuosum (Sw.) DC.
Leguminosae
1
0
Seed
Beggarweed
Desmodlum tortuosum (Sw.) DC.
Leguminosae
0
1
Seed
Florida Pusley
Rlchardla scabra L.
Rublaceae
3
2
Leaflet
Slcklepod
Cassia obtuslfolla L.
Leguminosae
2
2
Flower, Outside
Hairy Indigo
Indlgofera hirsuta L.
Leguminosae
1
1
Flower, Outside, Dead
Hairy Indigo
Indlgofera hirsuta L.
Leguminosae
9
18
Flower
Hairy Indigo
Indlgofera hirsuta L.
Leguminosae
2
0
Leaflet
Hairy Indigo
Indlgofera hirsuta L.
Leguminosae
0
2
Leaflet, Dead
Hairy Indigo
Indlgofera hirsuta L.
Leguminosae
0
2
Flower
Common Beggar Tick
Bldens alba (L.) DC.
Composltae
aTotal males 89.
^Total females 131.
Adults fed at the surfaces of plant structures or in flowers.
^Dicotyledonous plant.

Table 3.8. Number of adult males of the velvetbean caterpillar feeding in a soybean field at
Green Acres Research Farm, Alachua County, FL, from 1980-82. Also, number of males
per aggregate, number of aggregates, and description of food site are provided.
No. of3
Males Feeding
No. of Males^
Per Aggregate
No. ofC
Aggregates
Description of Food Site^
5
0
0
Human Skin
4
0
0
Vinyl Raincoat
1
0
0
White Cotton Pants
1
0
0
Aluminium Push Button, Head Lamp
1
3
0
0
Bamboo Sticks
ON
123
29, 22, 18, 17, 12,
9, 5, 3, 3, 3
10
Aerial and Sweep Nets (Bag and Pole)
1
16
15
1
Black Saran Screen
24
15, 5, 3
3
Brown Saran Screen
2
0
0
Barb Wire Fence
aTotal Male Feeding = 179.
^Total Males in Aggregates = 159.
c
Total Aggregates = 14.
^Males fed at the surfaces of food sites.

68
Figure 3.4. Aggregation of velvetbean caterpillar males on an aerial
net. Males are feeding at the surface of the net (bag and
pole). Photograph was made in a 1 ha soybean field at the
Green Acres Research Farm, Alachua County, FL, September 7,
1983.

Figure 3.5. Aggregation of velvetbean caterpillar males on the screen of an insectary. Males are
feeding at the surface of the screen. Photograph was taken at the edge of a 1 ha soybean
field at the Green Acres Research Farm, Alachua County, FL, September 14, 1983.

70
extremely docile and could be touched frequently without cessation of
feeding. How males were attracted to these sites is unknown, but they
may have utilized these sites to acquire salts, as some male lepidoptera
aggregate and acquire salts (see Arms et al. 1974).
The most prevalent feeding site was the raceme of bahiagrass,
accounting for 177 (39%) of all observations (see Tables 3.4, 3.6 and
3.7). Fifty males and 84 females were observed, for a sex-bias ratio of
1:1.7 (male to female). The nature of this bias (if valid) is unknown,
as is the nutritional source obtained on or from the bahiagrass. An
adult is shown feeding at a raceme of bahiagrass in Fig. 3.6. Adults
fed frequently on legumes, accounting for 99 (22%) of the observations
(see Tables 3.4 and 3.5-3.7). No sexual bias was noted. These adults
may have acquired various plant compounds, but the compounds and their
utilization are unknown. Nineteen adults fed at dead plant tissue, and
no sexual bias was exhibited (see Table 3.7 and Fig. 3.7). With one
exception, these dead tissues were all from legumes. The compounds
acquired from these dead plant tissues, as well as their utilization,
are unknown. Some moths of the Ctenuchidae and Arctiidae feed on dead
and withered plants as a possible nitrogen source (see Goss 1979).
The occurrence of males feeding in aggregations was an uncommon
sight in the field and contributed to the large standard errors shown in
Fig. 3.2(C) (see also Appendix C, Table C.9). Male aggregations may
have been found more often if an effort had been devoted solely to
aggregate location during each observation period. Observation of
additional aggregates may have resulted in smaller standard errors, as
well as a different temporal pattern in their occurrence. Nevertheless,
males were prevalent in aggregates during the fifth hour after sunset

Figure 3.6. Adult velvetbean caterpillar feeding at the surface of a
bahiagrass raceme. Photograph was made at the edge of a 1
ha soybean field on the Green Acres Research Farm, Alachua
County, FL, 16 September 1985.

Figure 3.7. Adult velvetbean caterpillar feeding at the surface of a dead soybean leaflet. Photograph
was made in a soybean field in Melrose, FL, Alachua County, 7 October 1983.

73 -
when ca. 60% of all aggregated males were observed. Interestingly,
almost all mating (79.25%) occurred in the first four hours after
sunset, but the adaptive significance of the temporal relationship
between mating and aggregating is obscure.
Feeding by non-aggregated males occurred throughout scotophase,
except for the seventh hour when no feeding was recorded [Fig. 3.2(D)
and Appendix C, Table C.10]. Feeding by males probably occurred in the
seventh hour but only four observational periods were completed at this
time. The temporal occurrence of feeding by all males (aggregated and
non-aggregated) was non-uniformly distributed throughout scotophase, as
ca. 82% occurred within the first 6 h after sunset [see Fig. 3.2(D) and
Appendix C, Table C.11]. This non-uniform distribution was dominated by
the fifth post-sunset hour (43.65%) when large numbers of males
aggregated. Leppla (1976) found that colony males fed uniformly
throughout scotophase.
The temporal occurrence of feeding by females was non-uniformly
distributed, as 74.67% occurred between hours 5 and 11 post-sunset [see
Fig. 3.2(F), Appendix C, Table C.12]. The sample mean of hour 8
accounted for 32% of all female feeding, but why is unknown.
Interestingly, the first four hours post-sunset appeared to be devoted
to mating and oviposition when 79.25% and 84.72% of each activity
occurred, respectively. Females apparently partitioned their time
between feeding, mating, and ovipositing and may have acquired an
increased reproductive fitness from this partitioning (i.e., ovipositing
and mating during early scotophase may be more beneficial than feeding).
Leppla (1976) found that colony females fed throughout scotophase but
that feeding increased during the second half of scotophase.

74 -
The temporal occurrence of feeding by unsexed adults was reasonably
uniform throughout the night [see Fig. 3.2(G) and Appendix C, Table
C.13]; unsexed adults flew out of sight before a positive sexual
identification could be made. The uniform inability to sexually
identify adults indicates no temporal bias occurred in identification of
unsexed adults during scotophase. The occurrence of feeding by all
adults (males, females, and unsexed) differed noteable for hours five,
eight, and twelve [see Fig. 3.2(H) and Appendix C, Table C.14]. These
hours corresponded, respectively, to peaks in male (aggregated) and
female feeding and to no feeding at all. The feeding occurrence of
males (not aggregated), females, and unsexed adults was different,
particularly for the eighth hour, which corresponded to peak female
feeding [see Fig. 3.2(1) and Appendix C, Table C.15]. Overall, feeding
by VBC adults occurred at all hours of the night (except for the 12th
hour).
Predators
Spiders were the only observed predators of VBC adults. No effort
was made to identify all the spider species at the study site or to
obtain density estimates of the recorded spider predators. Peucetia
viridans (Hentz) and Misumenops spp. were the most frequently observed
spiders. Peucetia viridans was found throughout the field (edge and
interior), usually on dicotyledonous plants and high above the ground
(ca. 1 m or higher). Misumenops spp. were found only at the field edge,
usually on monocotyledonous plants and close to the ground (ca. .5 m or
less). Most of the orbweavers were found at the field edge, with webs
at a height between ca. .5 and 1.5 m.
Six species of spiders were recorded as predators, with 26
predation records (see Table 3.9); all records were obtained during

Table 3.9. Records of spider predation on adult velvetbean caterpillar (VBC) from 1980-83
at Green Acres Research Farm, Alachua County, FL, in a 1 ha soybean field. All
records occurred during scotophase.
Spider6 _
Spider Stage VBC
Date
(D-M-Y)
Time^
c
Location
Spider Scientific
Name4*
Common
Name
Spider
Family
and
Sex
Adult
Sex
19-S-81
2047
E.
Bahlagrass
Peucetla
vlrldans
(Hentz)
Green Lynx
Oxyopldae
*. +
M
19-S-81
2058
I.
Soybean
Peucetla
vlrldans
(Hentz)
Green Lynx
Oxyopldae
*, +
M
24-S-82
2112
I.
Florida Pasley
Peucetla
vlrldans
(Hentz)
Green Lynx
Oxyopldae
*, +
M
I7-S-81
2115
E,
Bahiagrass
Peucetia
vlrldans
(Hentz)
Green Lynx
Oxyopldae
*, +
F
19-S-83
2130
E.
Sandbur
Peucetla
vlrldans
(Hentz)
Green Lynx
Oxyopldae
A A

M
24-S-82
2147
I.
Soybean
Peucetla
vlrldans
(Hentz)
Green Lynx
Oxyopldae
F
24-S-82
2223
I.
Soybean
Peucetla
vlrldans
(Hentz)
Green Lynx
Oxyopldae
* +
F
09-S-81
2303
I.
Soybean
Peucetla
vlrldans
(Hentz)
Green Lynx
Oxyopldae
*. +
M
03-S-82
2323
E,
Beggarweed
Peucetla
vlrldans
(Hentz)
Green Lynx
Oxyopldae
A, +
M
03-S-82
2340
I.
Slcklepod
Peucetla
vlrldans
(Hentz)
Green Lynx
Oxyopldae
A. +
M
25-S-82
0023
I.
Hairy Indigo
Peucetia
vlrldans
(Hentz)
Green Lynx
Oxyopldae
* P
M
04-S-82
0052
I.
Soybean
Peucetia
vlrldans
(Hentz)
Green Lynx
Oxyopldae
A, +
M
04-S-82
0111
I.
Slcklepod
Peucetla
vlrldans
(Hentz)
Green Lynx
Oxyopldae
A, F
M
04-S-82
0136
I.
Soybean
Peucetla
vlrldans
(Hentz)
Green Lynx
Oxyopldae
*, +
M
21-A-81
0545-0701
I.
Soybean
Peucetia
vlrldans
(Hentz)
Green Lynx
Oxyopldae
I. +
+
25-A-81
0545-0703
E,
Grass
Peucetla
vlrldans
(Hentz)
Green Lynx
Oxyopldae
*. +
M
15-S-8I
0545-0714
I.
Soybean
Peucetia
vlrldans
(Hentz)
Green Lynx
Oxyopldae
*, +
M
03-S-8I
2230
E.
Bahlagrass
Mlsumenops celer
(Hentz)
Crab
Thomlsldae
A, +
M

Table 3.9 (continued)
Date3
(D-M-Y)
Time^
Q
Location
Spider Scientific Name1*
Spider
Common
Name
Spider
Family
Spider6
Stage
and
Sex
VBCf
Adult
Sex
16-A-8I
0000-0700
E,
Grass
Mlsumenops celer (Hentz)
Crab
Thomisldae
A, +
M
09-0-82
0530
E,
Hairy Indigo
Mlsumenops celer (Hentz)
Crab
Thomisldae
A, +
M
01-S-81
0545-0607
E,
Grass
Mlsumenops celer (Hentz)
Crab
Thomisldae
A, +
F
15-S-81
0545-0714
E,
Bahlagrass
Mlsumenops formoclpes (Walckenaer)
Crab
Thomisldae
A, F
M
I7-S-8I
2100
I.
Soybean
Eriophora ravllla (C. L. Koch)
Orbweaver
Araneldae
A. F
M
24-S-82
2332
E.
Soybean
Neoscona arabesca (Walckenaer)
Orbweaver
Araneldae
A, F
M
05-0-82
0550
E,
Soybean
Neoscona arabesca (Ualckenaer)
Orbweaver
Araneldae
A, +
M
I5-S-83
0200
E.
Bahlagrass
Acanthepelra sp.
Orbweaver
Araneldae
I. +
F
aD-M-Y -
Date, Month,
, Year; A August,
S = September, 0 October; 81 1981
, 82 1982,
83 1983.
If the exact time of a predation record is not given, the record occurred during the hyperated times.
c
E = Edge of field; record was observed within I m of the field edge. I Inside field; record was observed in the
field and at least 1 m from the field edge. Grass unidentified grass. Bahlagrass Paspalum notatum Flugge.
Hairy Indigo Indlgofera hirsuta L. Soybean Glycine max (L.) Merr. Beggarweed Desmodlum tortuosum (Sw.)
DC. Slcklepod Cassia obtualfolla L. Florida Pusley Rlchardla scabra L. Sandbur Cenchrus sp.
^Except for P. vlrldans, all spiders were identified by Dr. G. B. Edwards, Taxonomic Acarologlst and Curator, Florida
State Collection of Arthropods, Gainesville, FL. P. vlrldans1 were identified by the author, but four of these
specimens were reconfirmed by Dr. Edwards.
6
I = immature, A adult, F female, = undetermined stage, + undetermined sex.
* + = undetermined sex, M male, F female

77
scotophase. A male-prey bias exists, as 20 of 26 prey were males; adult
VBC sex-ratio was ca. 1:1 (see Chapter IV). The nature of this bias is
unknown but may be due to aggressive chemical mimicry of VBC mating-
pheromone by some or all of these spiders (see Foelix 1982).
Most of the predation records, 17 out of 26 (65%), were of P.
viridens. Fourteen of these records occurred between 2047 and 0136, the
time period when VBC adults were most active. Misumenops spp. accounted
for 5 of the 26 records (19%) and the orbweavers accounted for 4 of the
26 records (15%). The large number of P. viridens records may be a
reflection of where observation time was concentrated (i.e., in the
field). Also, the webs of orbweavers were destroyed frequently by
research personnel walking through the field. Figures 3.8 and 3.9 are
photographs of two spider predation records.
Conclusions
The temporal patterns of several adult activities (flight, mating,
oviposition, and feeding) were observed and quantified in the present
study, as were some environmental factors that affected these patterns.
The suspected adaptive significance of these activity patterns was
discussed. Flight occurred primarily at night. During the day, adults
resided in the field but only after the soybean canopy had begun to
close or was closed. During the day adults flew only when disturbed or
rarely if feeding. Approximately 79% of all mating occurred within the
first four hours of scotophase. Mating occurred usually at the top of
soybean plants, a height of ca. .8 m. Placement of pheromone traps near
the canopy top in the field would result probably in the largest capture
of males. Approximately 96% of all oviposition occurred within the
first six hours of scotophase and feeding occurred primarily at night.
Females utilized nutritional sources that may have affected egg

Figure 3.8. Green lynx spider [Peucetia viridans (Hentz)] preying on an adult male velvetbean
caterpillar. Photograph was made at the edge of a 1 ha soybean field at the Green Acres
Research Farm, Alachua County, FL, 19 September 1983.

Figure 3.9. Orbweaver spider (Acanthepeira sp.) preying on an adult female velvetbean caterpillar.
Photograph was made at the edge of a 1 ha soybean field at the Green Acres Research
Farm, Alachua County, FL, 15 September 1983.

80 -
production. Males utilized some food sources that females did not use.
At these sources, males usually occurred in aggregations. Future
research efforts might examine more quantitatively the affect of adult
age, adult nutrition, host plant density and physiology, and weather
factors on flight, mating, oviposition, and feeding. Some of these
efforts might be accomplished by observing individual moths.
Observations of adult activities were density-dependent. Sightings
of mating, oviposition, feeding, and mortality were not observed in June
and July at low adult density, but were observed in August, September,
and early October at high adult density (see Chapter IV for adult
density data). In future studies of adult behavior, concentration of
observation time during high adult density should yield more behavioral
observations.
The present study has expanded our knowledge of VBC behavior and
provided information essential for the construction of a model of adult
and egg populations (see Chapter VI). Knowledge of the temporal
occurrence of flight and some environmental factors affecting flight
allowed for the development of an unique adult sampling method (and the
subsequent acquisition of adult density data) and a better understanding
of adult density fluctuations (see Chapter IV). Knowledge of the
temporal occurrence of oviposition allowed for the development of an
unique sampling method for eggs and the subsequent acquisition of egg
density data (see Chapter V). The measurements of adult and egg
densities are presented in the next two chapters. These density
measurements were necessary for model construction and validation (see
Chapter VI).

CHAPTER IV
MEASUREMENT AND ANALYSIS OF INTRAFIELD
ACTIVITY OF ADULT VELVETBEAN CATERPILLAR
Introduction
The velvetbean caterpillar (VBC) is believed to "overwinter" in
much of the Caribbean Basin and South America and is conjectured to move
annually into the southern United States (Watson 1916a, Herzog and Todd
1980, Buschman et al. 1981a). The magnitude and timing of VBC
immigration are unknown, as no direct evidence exists (Buschman et al.
1981a). Based on density data of larvae, adult VBC evidently invade
soybean in northern Florida during late June, July and August (see
Greene 1976, Menke and Greene 1976, Linker 1980). Following adult
colonization, larvae reach peak densities in August September and,
occasionally, early October (Greene 1976, Menke and Greene 1976, Linker
1980). With the October onset of soybean senescence, VBC adults are
suspected to move onto alternate hosts where their larvae have been
collected (Ellisor 1942, Greene 1976, Buschman et al. 1981a). Larvae
and pupae appear incapable of overwintering in northern Florida
(Buschman et al. 1977); thus, infestation of soybean the following year
depends on VBC adult immigration (see Watson 1916a, Buschman et al.
1977, 1981a).
Current management of VBC is directed at control of in-field larval
densities (Linker 1980). This type of management treats the symptoms of
the pest problem and not the cause (see Stimac and Barfield 1979,
Barfield and O'Neil 1984). In a simulation model of soybean/VBC
81

- 82
dynamics, Wilkerson et al. (1983) found that changes in the density and
influx timing of adults into soybean resulted in notable differences in
soybean yield and grower profit (from -$289.63 to $169.21/ha)(see Table
1.1). Clearly, knowledge of when and why adults immigrate into soybean
could provide a better understanding of VBC dynamics and lead to more
enlightened management.
The present study was initiated to quantify and model adult and egg
populations of VBC within soybean. Model construction depended on
estimates of adult and egg densities. Data on adult density were
essential for model initialization and data on egg density (see Chapter
V) were required to assess the impact of adult reproduction in the field
(i.e., the mere presence of adults does not connote the presence of eggs
and resultant larval defoliators). In the present study, adult VBC
density was monitored in soybean, the reproductive status of adult
females was determined, and select environmental variables were
monitored.
Materials and Methods
Adult Sampling
Adult VBC density was monitored (1980-82) in a 1 ha soybean field
(cv. Bragg), at the University of Florida's Green Acres Research Farm
(ca. 22.5 km west of Gainesville, FL, Alachua County). Specific
agronomic practices and soybean phenological stages are listed in
Appendix A. Adult VBC density was measured with two devices. The first
device, a blacklight trap (BLT), was used in all three years, was placed
in the field, and was situated 21.2 m diagonally from a field corner and
15 m from the closest field edges. The blacklight trap in 1980 did not
conform to the BLT standards recommended by the Entomological Society of
America, but the trap in 1981 and 1982 did meet the society's

- 83 -
recommendations (see Harding et al. 1966). New 15 w bulbs (General
Electric F15T8-BL) were installed each field season, and the funnel top
of each trap was positioned 1.5 m above the ground. Isopropanol (99%)
was used as the killing agent and was changed daily (1.89 L/day). Adult
VBC were segregated daily from total trap catch, counted, sexed and
stored in 5% formalin.
The second adult monitoring device, an adult trap-cage, was used
during the day in 1982 (Fig. 4.1). Development of this trap resulted
from the observation that adults reside in the soybean field during the
day (see Chapter III). Outside dimensions of the cage were 4.6 x 4.6 x
2.1 m, and the frame was constructed of 1.25 inch polyvinylchloride pipe
(PVC, PR160). The frame was covered with Lumite Saran Screen (Chicopee,
Style //51821000) that extended 0.3 m below the cage on all sides (i.e.,
extension flaps). Four people carried the cage (one at each corner) via
0.9 m handle and walked one row distant from the sampled rows. The cage
covered six rows of soybean and was carried above the crop canopy to
avoid the flushing of VBC adults. At each sample site, bearers dropped
the cage rapidly and quickly buried the extension flaps with soil. The
cage was entered via a full length zipper on one side.
Each week, six simple random samples were taken with the adult
trap-cage. One hour was spent inside the cage at each sample site. To
assist in the exposure and capture of adults inside the cage, all weeds
were removed and soybean foliage was shaken vigorously. Adults were
caught with an aerial net and placed initially in a vial of 99%
isopropanol. Most adults were caught within 20 min and none were caught
after 40 min. Adults were counted, sexed, and stored in 5% formalin.

Figure 4.1. Trap-cage used to collect adult velvetbean caterpillar in a 1 ha soybean field during
1982 at the University of Florida's Green Acres Research Farm, Alachua County, FL.

85 -
Female Dissections
Females from the 1981 blacklight trap were dissected and placed
into four reproductive categories (i.e., physiologically aged) based on
a visual assessment of fat body content, ovary development, and the
number of spermatophores (see Callahan 1958), Categories were (1)
unmated, no spermatophore, (2) mated, fat body content full to 1/3
depleted, (3) mated, fat body content between 1/3 and 2/3 depleted, and
(4) mated, fat body content 2/3 or more depleted. These categories were
established with the assumption that category 1 females had the lowest
reproductive output, category 2 females had the highest, and categories
3 and 4 had successively lower outputs. Unmated females were placed
into three categories: (1) full, fat body content full to 1/3 depleted,
(2) medium, fat body content between 1/3 and 2/3 depleted, and (3)
empty, fat body content 2/3 or more, depleted.
Physical Variables
Various physical variables were monitored during the study.
Variable descriptions, monitoring devices or sources of information,
monitor locations, frequency of variable readings, and years monitored
are provided in Table 4.1. Mean nightly measurements of the following
physical variables were regressed against BLT catch (unweighted and
weighted): vapor pressure deficit,* flight temperature, moonlight
illuminence, rainfall, wind speed, wind direction, and barometric
pressure. Equations used to determine mean physical variable values,
and those values, are given in Appendix D, Tables D.4-D.6. Weighted
*Vapor pressure deficit is a better representation of atmospheric
moisture than relative humidity (RH) because interpretation of RH
values are dependent upon temperature values (Anderson 1936).

Table 4.1. Description of physical variables monitored in Alachua County, FL, in 1981-82.
Physical
Variable
Monitoring Device
or Source
Site3
Location
Frequency
of Reading
Yearb
Monitored
Temperature (C)
Hygrothermograph, Weather
Measure Corp., Model H311
Edge (Ambient)
and Field
Continuous
81,82
Temperature (C)
Esterline AngusR PD2064
Microprocessor
Edge (Ambient)
Continuous
81,82
Relative Humidity (%)
Hygrothermograph, Weather
Measure Corp., Model H311
Edge (Ambient)
and Field
1 h
81,82
Rainfall (cm)
Universal Recording Rain
Gauge, Belfort Instr. Co.,
12" chart with dual springs
Edge
Continuous
81,82
Wind Speed (m/sec)
Gill, 3-cup Anemometer,
R. M. Young Co., Model
12102
Edge, 6.4 m
Height
15 min
81
Wind Direction0
Gill Microvane, R. M.
Young Co., Model 12302
Edge, 6.4 m
Height
15 min
81
Barometric Pressure
(MB)
Mirobarograph, Weather
Measure Corp., Model B211
Edge (Ambient)
Continuous
81,82
Sunset and Sunrise
Times, Length of Day
and Night
Oliverd
Alachua County,
FL
24 h
80,81,82

Table 4.1 (continued)
Physical
Variable
Monitoring Device
or Source
Site8
Location
Frequency
of Reading
Yearb
Monitored
Moon Phase and
Temporal Occurrence
Smith and Smith (1981),
Vohden and Smith (1982)
Alachua County,
FL
Nightly
81,82
Proportional
Moonlight Intensity
(lumens/m2)
Gardiner (1968)
Alachua County,
FL
Nightly
81,82
Opaque Cloud
Coverage
NOAA (1981; 1982)
Alachua County,
FL
Nightly
81,82
Edge was within 50 m of
the field edge. Ambient was
at a height of 1.5 m.
Field was within
the field,
at least 15 m from nearest field edge, and at a height of .2m.
b81 = 1981; 82 = 1982.
c
Actual readings were recorded by the Esterline Angus PD2064 Microprocessor.
^J. P. Oliver, Associate Professor of Astronomy, Department of Astronomy, University of Florida,
Gainesville, FL 32611.

88 -
values of BLT catch were determined with the equation:
WBLT = (RBLT SBLT)/(SBLT),
where WBLT = weighted blacklight trap catch,
RBLT = raw blacklight trap catch, and
SBLT = smoothed blacklight trap catch.
Weighted values of BLT catch represent the change in the proportional
magnitude of moths captured per night in the BLT. Smoothed values were
determined with a nonlinear data smoothing algorithm (3RSSH, twice)
based on running medians (see Velleham 1980, Ryan et al. 1982). Three
variable selection procedures were utilized: forward selection,
backward elimination, and maximum r2 improvement (i.e., forward
selection with pair switching). Models were selected based upon
parameter significance, residual plots, r2, and Mallows' Cp statistic
[for discussions of Cp see Mallows (1973) and Daniel and Wood (1980)].
Results and Discussions
Blacklight Trap
The total number of females, males, and adults (females and males)
captured per night (1980-82) in the BLT are shown in Fig. 4.2 (A-C) and
listed in Appendix D, Tables D.1-D.3. Comparisons of the number of
captured moths among years are difficult to make because of (1)
differences in BLT sizes, (2) electrical problems with the '80 BLT that
resulted in no catch during 9 nights, and (3) variation in the temporal
occurrences of trappingthe BLT ran for 71 days in '80, 116 days in
'81, and 123 days in '82. Nevertheless, initially-captured adults were
females in '80, males in '81, and both sexes in '82. Apparently, both
sexes make initial flights into soybean. Adult density during July and
August (Julian date 182 to 243) varied considerably among years. In
1981, BLT catch was depressed as only 698 adults were captured. In '80

TOTAL NUMBER/NIGHT TOTAL NUMBER/NIGHT TOTAL NUMBER/NIGHT
- 89 -
JULIAN DATE
Figure 4.2. Total number of velvetbean caterpillar moths captured in a
blacklight trap per night in a 1 ha soybean field at the
Green Acres Research Farm, Alachua County, FL: (A) 1980,
(B) 1981, and (C) 1982.

- 90 -
and '82, ca. three times that number were captured (2106 and 1989
adults, respectively). At this time of the field season, most of these
adults were moving into the field from outside sources. Differences in
the number of captured adults among years may have been due to the
amount of rainfall in the general area; adult dynamics are sensitive to
moisture (see Leppla 1976). In July and August of '81, 20 cm of rain
fell, while in '80 and '82 ca. 30 cm of rain fell or ca. 33% more rain
(see Table 4.2). Rainfall for all three years was below normal, but
July and August in '81 were particularly dry with less than half of the
70 year mean.
In '80, males were the predominant BLT catch during the first half
of the field season and females were predominant in the latter half. In
'81 males were the predominant catch throughout the field season and in
'82 both sexes were equally predominant [see Fig. 4.2 (A-C)]. The
reason for variation in sex predominance between years is unknown.
Adult appearance in the field was synchronized with the appearance
of eggs. In '81, eggs were found on July 24 (date 205) and consistently
thereafter (see Chapter V). Adults were captured consistently from July
22 (date 203). The first adult female was captured on this same date
[see Fig. 4.2(B) and Appendix D, Table D.2]. In '82, eggs were found
initially on July 6 (date 187) and consistently after July 17 (date
198)(See Chapter V). Adults were captured consistently from July 9
(date 190)[see Fig. 4.2(C) and Appendix D, Table D.3].
Female Dissections
All females captured in the BLT in 1981 were dissected and placed
into four reproductive categories (see Materials and Methods). A total
of 1288 females were dissected. Category 2 contained the largest number
of females (543), category 3 had the next largest (376), and categories

- 91 -
Table 4.2. Amount of rainfall recorded at the number 3 WSW
climatological station of the University of Florida,
Gainesville, FL, Alachua County. Cooperative
climatological station of the Agronomy Department and
NOAA.
Month
1980
Rainfall (cm)
1981
1982
Normal3
Rainfall (cm)
July
22.00
7.39
17.17
20.40
August
8.08
12.65
15.70
20.96
Total
30.08
20.04
32.87
41.36
Normal is 70 year mean.

92 -
4 and 1 contained smaller numbers (207 and 162, respectively); all mated
females (1126) contained mature and/or maturing eggs. Seventy-one
percent of all females belonged to categories 2 and 3. The total number
of females per category per night mirror similar results (see Fig. 4.3).
Based on BLT catch and dissections, most of the females in the field on
any given night were females with high reproductive potential.
Only mated females (categories 2 and 3) were caught initially.
Apparently, they moved into the field seeking oviposition sites*.
Unmated females were caught in increasing numbers after date 241, and
may have been individuals that completed their immature development in
the field. Adult generations in another noctuid pest of soybean, the
green cloverworm [Plathypena scabra (Fabricius)], have been indicated by
cyclic patterns of unmated females (see Buntin and Pedigo 1983), but
these cyclic patterns were not apparent in 1981 with VBC females (see
Fig. 4.3).
Unmated females were placed into three categories (see Materials
and Methods). Full and medium categories had essentially the same total
number of individuals (78 and 79, respectively), while the empty
category had only five individuals. The total number of unmated females
per category per night mirror similar results (see Fig. 4.4). Based on
BLT catch and these dissections, most unmated females in the field
should demonstrate a high reproductive output after mating. Also, most
females mated before their fat body had been depleted.
Spermatophores were removed from all mated females (1126) caught in
the BLT during 1981 with the following results: 1587 spermatophores
were counted, females contained one to four spermatophores, and the mean
*Eggs were first found in the field on date 205 (see Chapter V).

NUMBER OF FEMALES/REPRODUCTIVE CATEGORY
- 93 -
Figure 4.3. Total number of adult velvetbean caterpillar females per
reproductive category per night. Categories are (1)
unmated, no spermatophore, (2) mated, fat body content full
to 1/3 depleted, (3) mated, fat body content 1/3 to 2/3
depleted, and (4) mated, fat body content 2/3 or more
depleted. Females were caught in a blacklight trap during
1981 at the Green Acres Research Farm, Alachua County, FL.

NUMBER OF UNMATED-FEMALES/FATBODY CATEGORY
- 94 -
Figure 4.4. Total number of velvetbean caterpillar unmated adult
females per fat body content category per night.
Categories are full (fat body content full to 1/3
depleted), medium (fat body content 1/3 to 2/3 depleted)
and empty (fat body content 2/3 or more depleted). Females
were caught in a blacklight trap during 1981 at the Green
Acres Research Farm, Alachua County, FL.

95 -
number of spermatophores per female (SE) was 1.41 .019. Leppla
(1976) found that colony females contained one to six spermatophores
with a mean of 1.7 spermatophores per female. Wild females contained a
smaller range of spermatophores but about the same mean.
The mean number of spermatophores per female per reproductive
category (SE) is listed in Table 4.3. All three categories of mated
females exhibit a significantly different mean, indicating that the
number of successful matings tended to increase with female age. The
mean number of spermatophores per female per week varied between only
one and two spermatophores (see Fig. 4.5), indicating that mating
frequency was fairly constant over the field season and that most
females mated at least once. The large confidence intervals at dates
203 and 210 are due to small sample size (n = 2 and 3, respectively).
Adult Trap-Cage
The mean number of VBC per 21.16 m2 captured in the adult trap-cage
during 1982 rose and fell steadily through the field season [see Fig.
4.6(A-C), and Appendix D, Tables D.4 and D.5 for raw data and mean
values]. Initially, females were caught for two weeks before males were
captured (Fig. 4.6). Perhaps females move into and reside in soybean
before males. Densities of females and males, measured with the trap
cage and BLT, peaked at ca. the same time (see Figs. 4.2 and 4.6). The
mean densities of males and females from the trap cage peaked on date
246 seven days before female density peaked in the BLT and four days
after male density peaked in the BLT.
The capture of the first adults in the trap-cage (date 217, 5
August) corresponded with the closure of the soybean canopy; the canopy
closed from late July to early August. No adults were caught with the
traP-ca8e in the field prior to canopy closure but adults were caught in

- 96 -
Table 4.3. The mean number (SE) of spermatophores per female per
reproductive category of adult velvetbean caterpillar.
Females were caught in a blacklight trap during 1981 at
the Green Acres Research Farm, Alachua County, FL.
£
Reproductive
Category
Total Number
of Females
Mean*3
Spermatophores/Female
(SE)
1
162
0
2
543
1.19 .02 A
3
376
1.40 .03 B
4
207
2.00 .05 C
1 = unmated, no spermatophore.
2 = mated, fat body content full to 1/3 depleted.
3 = mated, fat body content between 1/3 and 2/3 depleted.
4 = mated, fat body content 2/3 or more depleted.
^Means followed by different letters are significantly different
according to the Kruskal-Wallis Test (a = .05).

MEAN NUMBER OF SPERMATOPHORES
4 -
3 -
2 -
I -
01 1 __i
200
I
VO
I
-1
210
_i
220
i i i i i i i i 1 1 1 1 1
230 240 250 260 270 280 290
JULIAN DATE (1981)
Figure 4.5. The mean number of spermatophores per adult velvetbean caterpillar female per week.
Females were caught in a blacklight trap during 1981 at the Green Acres Research Farm,
Alachua County, FL.

MEAN NUMBER OF ADULTS MEAN NUMBER OF MALES MEAN NUMBER OF FEMALES
- 98 -
I0r
6 -
4 -
2 -
A.
I I
O M I I I i I
200 210 220 230 240 250 260 270 280 290
IOr
2 -
0 u
B.
L
-J I I L.
I I
J 1 I 1 I l
200 210 220 230 240 250 260 270 280 290
|6r
- C.
12
L
l I
l 1 I L.
200 210 220 230 240 250 260 270 280 290
JULIAN DATE (1982)
Figure 4.6. Mean number ( 90% confidence interval) of velvetbean
caterpillar moths captured per sample (21.16 m2) with the
adult trap-cage: (A) females, (B) males, and (C) adults
(females and males). Trap-cage was used in a 1 ha soybean
field during 1982 at the Green Acres Research Farm, Alachua
County, FL.

- 99 -
the BLT prior to canopy closure. From dates 190-216, 121 adults were
caught in the BLT (see Fig. 4.2 and Appendix D, Table D.3). Based on
BLT and trap-cage data, and on behavioral observations (see Chapter
III), adults moved into the field at night but did not stay in the field
during the day until the canopy began to close. Also, females laid
eggs* in the field prior to being captured in the trap-cage. Adults may
take-up "residence" in the field at canopy closure due to changes in
atmospheric humidity or vapor pressure deficit.
Effect of Vapor Pressure Deficit
In 1981-82, ambient** vapor pressure deficit (VPD) was higher
during the day [see Figs. 4.7(A) and 4.8(A)], Field** VPD was high
during the day until the canopy closed ca. 30 July '81 (date 211) and 27
July '82 (date 208)[see Figs. 4.7(B) and 4.8(B)], In 1981, field VPD
during the day fell below 5 mm Hg consistently after date 210 [see Fig.
4.7(B)], Adults were first observed in the field on date 215. In 1982,
field VPD during the day fell consistently below 5 mm Hg after date 207
[see Fig. 4.8(B)], Adults were first observed in the field on date 214
and first captured in the trap-cage on date 217. In 1981 and 1982,
adults moved into the field after the VPD had fallen below 5 mm Hg.
Late in the field season of 1982, as the soybean began to senesce
and the VPD rose above 5 mm Hg, adults continued to be caught in the
trap-cage. The reason for the continued presence of adults in soybean
at this time is unclear but may have been due to physiological changes
*Eggs were first collected in samples on 5 July 1982, or date 186 (see
Chapter V).
**Ambient and field VPD (day and night) are mean values based on
readings of temperature and humidity that were recorded at 1 h
intervals. See Appendix D, Table D.6, for formula used to calculate
VPD.

FIELD VPD (mmHg) AMBIENT VPD (mmHg)
100 -
JULIAN DATE (1981)
Figure 4.7. Vapor pressure deficit (VPD) in a 1 ha soybean field in
1981 at the Green Acres Research Farm, Alachua County, FL:
(A) ambient VPD, and (B) field VPD.

FIELD VPD (mmHg) AMBIENT VPD (mm Hg)
101
JULIAN DATE (1982)
Figure 4.8. Vapor pressure deficit (VPD) in a 1 ha soybean field in
1982 at the Green Acres Research Farm, Alachua County, FL
(A) ambient VPD, and (B) field VPD.

102 -
within the moths; i.e., adults may have been more tolerant of higher VPD
at this time of the year. Behavioral observations* tend to support this
idea, as adults have been observed outside of soybean in areas of
apparent dryness at this time of the year. The occurrence of VBC in
these dry areas may be in response to the dry season that typically
begins at this time in tropical areas. Adults appear to be well adapted
for residing in dry leaf litter, as adults apparently are leaf mimics.
The strong diagonal line across the wings may mimic a leaf main-vein.
This diagonal line is maintained when the wings are held at rest. Other
markings and patterns on the wings may represent various shadings of
dried leaves and patches of lichens (see Figs. 3.1, 3.4, 3.6 and 3.7).
Sex Ratio
The sex ratio of adults caught in the BLT (per night) and the adult
trap-cage (per week) are shown in Fig. 4.9; sex ratio is expressed as
the number of males to total adults (Pianka 1978) The dashed line in
each figure represents the seasonal mean sex ratio. The sex ratio of
BLT adults was biased toward males for all three years but tended to
show a decrease in bias as the season progressed (i.e., the sex ratios
dropped below their mean values (see Fig. 4.9). The sex ratios for 80
and '82 are .54 and .51 (respectively) and are not significantly
different, while the sex ratio in 1981 was much higher at .69 and is
significantly different (see Table 4.4). Why the sex ratio for 1981 was
so high is unknown. The sex ratio of the trap-cage adults is .35, is
*0n 25 October 1981, 12 adults were observed at Osceola National Forest
(Baker County, FL) in the grass and leaf litter of Sandhill and Pine
Flatwood Communities. On 3 October 1982, 30 adults were observed at
Cumberland Island (Camden County, GA) on dead oak leaves in the dry
understory of a Maritime Community.

SEX RATIO/NIGHT SEX RATIO/NIGHT
JULIAN DATE JULIAN DATE
Figure 4.9. Sex ratio of velvetbean caterpillar adults caught in blacklight traps (BLT) and an adult
trap-cage (ATC) in a 1 ha soybean field at the Green Acres Research Farm, Alachua County,
FL: (A) 1980, BLT, (B) 1981, BLT, (C) 1982, BLT, and (D) 1982, ATC. Dashed line in all
graphs represents the seasonal mean sex ratio.
103

104
Table 4.4. Mean seasonal sex ratios of adult velvetbean
caterpillar caught in blacklight traps and an adult
trap-cage in a 1 ha soybean field at the Green Acres
Research Farm, Alachua County, FL.
Year
Trap3
Number
of Samples
Mean Sex Ratio*5
(SE)
1980
BLT
59
.54
.03 B
1981
BLT
89
.69
.02 C
1982
BLT
103
.51
.02 B
1982
ATC
49
.35
.05 A
aBLT = blacklight trap.
ATC = adult trap-cage.
^Means followed by different letters are significantly different
according to Duncan's Multiple Range Test (a = .05).

105
distinctly biased toward females, and is significantly different from
the other sex ratio values (see Table 4.4). Why this sex ratio is so
low and biased toward females is unknown, but perhaps females prefer to
reside in soybean while males prefer other sites.
Impact of Physical Variables
Select physical variables were regressed against BLT catch
(1981-82) of females, males, and adults (females and males). Regression
results with total BLT numbers are shown in Table 4.5. The parametric
coefficient of flight temperature was significant in all of the models,
except for females in 1982 (see Table D.6 for an explanation of flight
temperature). The parametric coefficient of vapor pressure deficit was
significant in three of the models, while the parametric coefficient of
moonlight intensity was the only other coefficient to show significance.
The effects of flight temperature and vapor pressure deficit on adult
catch are understandable, as temperature (see Chapter III) and VPD (see
Leppla 1976) affect VBC dynamics. The effect of moonlight intensity was
unexpected as field observations (see Chapter III) had not disclosed
such an affect; however, moonlight is known to affect the flight of many
moths (see Nemec 1971, Bowden and Church 1973, Douthwaite 1978). Values
of r2 were much higher in 1981 than in 1982, but a large amount of
variation in BLT response for both years was not explained.
Regression models for weighted BLT numbers are shown in Table 4.6.
The predictive capabilities of these models are very poor, as reflected
in their extremely low r2 values. Low r2 values for both total and
weighted BLT models demonstrate that the proportion of total variation
in the BLT responses, explained by the physical variables, is extremely
low in most cases. Unknown and/or non-monitored environmental variables
affected adult capture. Adult number may have varied due to area-wide

106 -
£
Table 4.5. Regression equations of physical variables and total
numbers of males, females, and adults of the velvetbean
caterpillar. Moths were caught in a blacklight trap at the
Green Acres Research Farm, Alachua County, FL. All
parametric coefficients significant at a = .05.
1981
Female = 39.18 3.15 (Temp) + 6.46 (VPD) 24.03 (Moon)
(r2 = .45)
Male = 75.91 4.73 (Temp)
(r2 = .18)
Adult = 110.96 6.73 (Temp)
(r2 = .23)
1982
Female = 37.82 11.04 (VPD)
(r2 = .05)
Male = 9.63 + 2.26 (Temp)
(r2 = .06)
Adult = 37.56 + 3.95 (Temp) 21.05 (VPD)
(r2 = .10)
Temp = temperature (C).
VPD = vapor pressure deficit (mm Hg).
Moon = moonlight illuminence.

107
£
Table 4.6. Regression equations of physical variables and weighted
numbers of males, females, and adults of the velvetbean
caterpillar. Moths were caught in a blacklight trap at the
Green Acres Research Farm, Alachua County, FL. All
parametric coefficients are significant at a = .05.
1981
Female = 16.74 0.25 (Moon) + 0.02 (Baro)
(r2 = .03)
Male = 0.58 0.003 (Windd)
(r2 = .01)
Adult, no variables met the .05 significance level.
1982
Female = 24.66 0.14 (VPD) + 2.94 (Rain) 0.02 (Baro)
(r2 = .05)
Male = 0.17 0.24 (VPD) + 0.26 (Moon) + 3.34 (Rain)
(r2 = .06)
Adult = 0.15 0.20 (VPD) + 0.27 (Moon) + 3.62 (Rain)
(r2 = .06)
Moon = moonlight illuminence.
Baro = barometric pressure (MB).
Windd = wind direction.
VPD = vapor pressure deficit (mm Hg).
Rain = rainfall (cm).

108 -
20 ha) occurred in the general area of the study and supported
populations of VBC.
Calibration of Adult Density
Linear regression was used to examine the relationship between the
total number of moths captured in the BLT and the total number of moths
in the field determined from trap-cage sampling data (see Appendix D,
Table D.4). Significant relationships were found for females, males,
and adults (females and males), although the proportion of the total
variation, as explained by the BLT catch, is low for all three models
(see Table 4.7). This low explanation is not surprising because BLT
catch fluctuates nightly (see Fig. 4.2) and can not be predicted very
well from weather variables (see Tables 4.5 and 4.6). Also, the models
in Table 4.7 are not realistic biologically. Based on positive
intercept values, these models demonstrate that moths are caught in the
field before they are caught in the BLT. Sample data do not support
this demonstration, as adults were caught in the BLT before they were
caught in the field. Smoothing* the BLT data provides more realistic
regression equations (i.e., negative intercepts) and increases r2 ca.
20% (see Table 4.8).
Conclusions
This study represents the first quantitative assessment of adult
VBC movement within a soybean field. Adult appearance (or density) in
the field was measured with a blacklight trap (BLT) and coincided with
the appearance of eggs, demonstrating that adult density can be
monitored with a BLT and that a BLT is sensitive to adult capture at low
*Data were smoothed with a nonlinear data smoothing algorithm (3RSSH,
twice) based on running medians (see Velleman 1980, Ryan et al. 1982).

109 -
Table 4.7. Regression equations of total daily number of velvetbean
caterpillar moths in the field and total nightly number of
moths caught in the blacklight trap during 1982 at the Green
Acres Research Farm, Alachua County, FL. Total number of
moths (females, males, and total adults) were determined
with adult trap-cage data.
Female
FF = 134.11 + 23.20 (FBLT),
where r2 = .26
FF = total number of field females,
FBLT = total number of BLT females.
Male
MF = 26.40 + 16.81 (MBLT)
where r2 = .28,
MF = total number of field males,
MBLT = total number of BLT males.
Adults
AF = 129.25 + 20.20 (ABLT)
where r2 = .32,
AF = total number of field adults,
ABLT = total number of BLT adults.

110
Table 4.8. Regression equations of total daily number of velvetbean
caterpillar moths in the field and total nightly smoothed
number of moths caught in the blacklight trap (BLT) during
1982 at the Green Acres Research Farm, Alachua County, FL.
Total number of moths (females, males, and total adults)
were determined with adult trap-cage data. BLT data were
smoothed with a nonlinear data smoothing algorithm (3RSSH,
twice) based on running medians (see Velleman 1980, Ryan et
al. 1982).
Female
FF = -68.55 + 30.06 (FBLT),
where r2 = .43,
FF = total number of field females,
FBLT = smoothed number of BLT females.
Male
MF = -218.40 + 31.10 (MBLT)
where r2 = .50,
MF = total number of field males,
MBLT = smoothed number of BLT males.
Adult
AF = 340.74 + 31.66 (ABLT)
where r2 = .55,
AF = total number of field adults,
ABLT = smoothed number of BLT adults.

Ill
densities. Placement of the trap in the field was necessary to achieve
this sensitivity. A number of physical variables were explored for
their effect on BLT catch. No consistently adequate correlations among
these variables and BLT catch were uncovered with regression techniques,
suggesting that other variables might affect adult density fluctuations
or that no simple linear relationships exist between these variables.
Future experimental work should be directed toward determining the
affect of various environmental variables on adult flight (e.g., wind
speed). Quantitative descriptions of these affects in the form of
mechanistic equations could be used to predict the capture of adults in
blacklight traps. Dissections of adult females revealed that most
females were found to be mated and potentially highly reproductive.
Early in the field season, mated females flew into the field and
contained large amounts of fat body, indicating that these females
probably completed their larval development on nearby hosts.
Absolute estimates of adult absolute density were obtained with a
unique sampling device, an adult trap-cage. Design and utilization of
this trap resulted from adult behavioral observations (see Chapter III).
Adult residency in the field during the day, as measured with this trap,
appeared to be delayed until an appropriate humidity level (5 mm Hg) had
been reached in the field during the day. Adult departure from the
field, as soybean senesced, apparently was not affected by the same
humidity level. To assess the true impact of humidity on VBC dynamics
will require extensive experimentation in the field on a year-round
basis in both soybean and other hosts, as well as the completion of
detailed laboratory experiments.
Estimates of the relative and absolute densities of adults were
calibrated with a regression equation. This equation could be used to

112
predict the number of adults in the field, given BLT catch. The number
of adults in the field, as predicted by this equation, could be modified
with mechanistic equations that describe the impact of environmental
variables on adult capture in a blacklight trap. These mechanistic
equations would exert their influence on the parametric coefficients of
the regression equation. Overall, data that were critical to the
construction of a model of adult and egg numbers of VBC were obtained
(see Chapter VI): adult female density, female reproductive potential,
and a calibration equation to convert BLT catch into field densities.
Model completion required only one more piece of information, egg
density data (see Chapter V).

CHAPTER V
MEASUREMENT OF EGG DENSITY
Introduction
Velvetbean caterpillar (VBC) larvae are a major defoliators of
soybean in the Gulf Coast area of the United States (Herzog and Todd
1980). Adult VBC immigrate into soybean fields annually and pest
problems result from oviposition by females and eclosin of larvae (see
Ellisor 1942, Greene 1976, Herzog and Todd 1980, Buschman et al. 1981a,
1981b). As is the case for most pests, current management of VBC is
directed at the symptoms of the pest problem (i.e., controlling larvae)
and not the cause (i.e., sources of adults)(see Barfield and O'Neil
1984). Not surprisingly, virtually nothing is known about the timing
and magnitude of adult movement or oviposition in soybean (see Rabb and
Kennedy 1979, MacKenzie et al. 1985). Wilkerson et al. (1982) used a
soybean/VBC dynamics model to describe how variation in the timing and
magnitude of adults resulted in notable differences in soybean yield and
grower profit (from -$289.63 to $178.43, see Table 1.1). Adult and egg
densities used in the model were determined from estimated larval
densities (Stimac,* personal communication). Examination of adult
*J. L. Stimac, Associate Professor, Department of Entomology and
Nematology, University of Florida, Gainesville, FL. 32611. Larval
densities at time "t" were used to determine egg and adult densities at
time "t-1" by calculating the densities of adults and eggs required to
produce the known larval densities. Mortality values of adults and
eggs were used in these calculations.
113

114
movement into soybean by quantifying adult and egg densities should
provide better insight into the management of this pest.
Movement of VBC adults in a soybean field will be examined with a
model of adult and egg populations in Chapter VI. Adult and egg density
data were required for model construction. Adult density data are
reported in Chapter IV and the present study is a report of egg density
data.
Determination of egg density demanded the resolution of several
methodological problems. First, confusion existed in the literature on
the physical appearance of VBC eggs, particularly egg color (see Watson
1916a, Douglas 1930, Hinds 1930, Ellisor 1942, Greene et al. 1973,
Gutierrez and Pulido 1978). Second, little was known about Lepidoptera
eggs found on soybean plants (see Herzog and Todd 1980). Third,
conflicting reports existed as to whether VBC eggs could be sampled (see
Greene et al. 1973, Ferreira and Panizzi 1978). Lastly, egg and adult
densities needed to be assessed simultaneously to describe the
relationship between the two life stages, a formidable problem (see
Oloumi-Sadeghi et al. 1975, Lopez et al. 1979, Buntin 1980, Hogg and
Gutierrez 1980, Pedgley and Betts 1980).
Materials and Methods
Egg Development and Coloration
From 1980-84, VBC eggs from colony and wild adults were examined to
determine their developmental times and coloration. Colony females were
used in all years, except for wild females in 1983. Wild females were
collected on 27 September 1983 with an aerial net in a 10 ha soybean
field (cv. USV1) in Alachua County, FL. All females were maintained at
26.7 1C,

115
an individual oviposition cage and supplied with an ovipositional
substrate of green paper* (see Moscardi 1979). Eggs were collected at
0.5 h after darkness by removal of the ovipositional substrate.
To determine temperature-dependent egg development, all collected
eggs (from colony and wild adults) were maintained in growth chambers at
a series of constant temperatures, 14L:10D photoperiod, and > 90% RH.
In 1980-82, eggs were kept in Percival Growth Chambers (Model I-35LL)
and, in 1983-84, in walk-in chambers (2.2 x 2.5 x 2.3 m). Egg
development was studied at 4.0, 6.4, 10.4, 14.8, 19.5 and 26.7 1C
(1980-81); at 23.9 and 26.7 1C (1982); at 26.7 1C (1983); and at
18.3, 21.1, 23.9, 26.7, 29.9, and 32.2 1C (1984). Egg coloration
and development were monitored with a 70X dissecting microscope at
variable time intervals (1980-81) and at hourly intervals (1982-84).
Field Sampling of Velvetbean Caterpillar Eggs
Eggs were sampled (1981-1982) twice a week in a 1 ha soybean field
(cv. Bragg)** at the University of Florida's Green Acres Research Farm
(ca. 22.5 km west of Gainesville, FL, Alachua County). Plants were
selected with simple random allocation, cut at soil line, removed from
the field and placed in a walk-in growth chamber (2 1C); plant stems
were placed in water to delay leaf wilt. In 1981, 70 randomly selected
plants were sampled on each sample date during the hour just before and
after sunset***. Sample unit size equaled one plant. In 1982, 30 to
*Springhill Bond/Offset International Paper Co., color green, 10M
weight, long grain.
**See Appendix A for agronomic practices and soybean phenological
stages.
***Oviposition rate during these times is known to be extremely low (see
Chapter III).

116 -
140 plants were sampled on each sample date between 0430 and 0630*.
Sample unit size varied from one to two plants (see Appendix F for egg
density data). Differences in sampling between 1981 and 1982 reflected
knowledge gained on the temporal occurrence of oviposition (see Chapter
III) and on temperature-dependent egg development. In all years, plants
were removed individually from the walk-in chamber and all plant
surfaces were searched for eggs. Typically, one to three days were
required to search all the plants. Eggs were examined with a 70X
dissecting microscope and identified to species (see Appendix E for an
identification key of Lepidoptera eggs on soybeans). All VBC eggs were
aged by coloration. On the first day of each sample date, all light-
green VBC eggs were held and checked for viability. Eggs that speckled
were considered viable (see below). Field temperature was monitored
continuously at 0.2 m above ground with a hygrothermograph (Weather
Measure Corp., Model H311).
Results and Discussion
Egg Development and Coloration
Velvetbean caterpillar eggs demonstrated a series of color changes
during development that were temperature-dependent. "Freshly-laid" eggs
typically were light green but also demonstrated off-white, transparent
and faintly-green colors [Fig. 5.1(A)]. "Middle-aged" eggs were colored
like freshly-laid eggs but were speckled brownish red; speckles also
were brown, reddish brown and rarely white in color [Fig. 5.1(B)], Eggs
about to hatch were light brown, or "brownish", with a visible larval
head-capsule [Fig. 5.1(C)],
*Ovipositional rate during these times is known to be extremely low (see
Chapter III).

117
Figure 5.1. Eggs of the velvetbean caterpillar: (A) "freshly-laid"
egg, light green in color, (B) "middle-aged" egg, light
green in color with brownish-red speckles, and (C)
"brownish" egg (i.e., about to hatch), light brown in
color.

118 -
Mean development times (from 1982 data) for egg speckling,
browning, and hatching were significantly different (a = 0.05) between
23.9 and 26.7C (Table 5.1). All eggs were light green when oviposited,
but 15 failed to speckle (12 at 23.9C and 3 at 26.7C). All 15 of
these eggs withered several days after oviposition and proved to be
non-viable. All other eggs demonstrated the speckling pattern that
persisted until browning. Thus, two vital components of the egg
sampling plan were assessed: (1) the color morphs associated with egg
development and (2) the temperature-dependency of egg development and
color changes.
Eggs from wild females demonstrated the same color changes as those
from colony females at 26.7C (Fig. 5.1); however, wild eggs developed
(and changed color) significantly faster (a = 0.05)(Table 5.1). The
reason for this result is unknown but could be an artifact of the small
number of colony females that were examined (n = 3).
Mean development time and rate for speckling were determined (with
1984 data) at six different temperatures with eggs from colony adults
(Table 5.2). Linear regression between developmental rate and
temperature yielded the following equation:
y = -0.080430 + 0.006566(x),
where y = developmental rate of speckling, and
x = temperature (C).
The coefficient of determination (r2) was 0.90. Slope and intercept
parameters were determined with all observations and not mean values.
The developmental zero (DZ) for speckling was 12.25C (Fig. 5.2), and
the number of degree-hours required for speckling (thermal constant) was
153.27 (Table 5.2). Replacement of the developmental rate of colony

3 Id c
Table 5.1. Mean developmental time of speckled brownish and hatched velvetbean caterpillar eggs
at two
study.
different
temperatures.
Colony (1982)
and
wild (1983) females
were
used in the
Speckled Eggs^
Brownish Eggs^
Hatched Eggs^
Female
No. of
Temp.
n
x SE
n
x SE
n
x SE
Source
Females
(C)
(h)
(h)
(h)
Colony
4
23.9
73
18.9 .23A
67
106.8 .38D
65
117.2 .44G
Colony
3
26.7
65
13.3 .26B
65
60.7 .21E
61
67.1 .24H
Wild
10
26.7
166
9.5 .07C
158
! 59.1 .14F
157
64.0 .151
2
Speckled refers to an egg that is typically light green with brownish-red speckles.
^Brownish refers to an egg that is light brown with a visible head-capsule,
c
Hatched refers to larval eclosin.
^Means followed by different letters are significantly different according to Kruskal-Wallis Test (a =
.05).
119

120 -
Table 5.2. Mean developmental time and rate (SE) for speckling to
occur in VBC eggs from colony females at six different
temperatures. Mean number of degree-hours required for
speckling (thermal constant) was 153.27.
Mean Development
Temp.
(C)
Number
of
Females
Number
of
Eggs
Time (SE)
(h)
Rate (i
(1/h)
:SE)
Degree-Hours
18.3
15
223
21.5 .09
.047 .
0002
130.72
21.1
15
215
16.3 .07
.062 .
0002
144.42
23.9
15
212
14.5 .10
.070 .
0005
168.55
26.7
15
220
12.7 .09
.080 .
0006
182.85
29.4
15
218
8.8 .05
.114 .
0006
151.27
32.2
15
214
7.1 .02
.141 .
0004
141.79

DEVELOPMENTAL RATE (I/HOUR)
121
Figure 5.2. Developmental rate of speckling in VBC eggs at six
different temperatures. Both colony and wild eggs were
studied at 26.7C. Developmental zero (DZ) for speckling
was 12.25C, and 153.27 degree-hours were required for
speckling to occur. Mean estimates are shown in the figure
for ease of view.

122
eggs at 26.7C with the rate for wild eggs (see Table 5.1 and Fig. 5.2)
yielded the following equation:
y = -0.082865 + 0.006826(x).
The coefficient of determination (r2) was 0.94. Slope and intercept
parameters were determined with all observations and not mean values.
The slope of this equation does not differ significantly (a = 0.05) from
the slope of the previous equation, indicating that the difference in
developmental rate between wild and colony eggs at 26.7C does not
significantly affect the relationship between temperature and egg
developmental rate.
Field Sampling of Velvetbean Caterpillar Eggs
The thermal constant (153.27 degree-hours) was used to age eggs
from field samples. Plants were removed from the field before
degree-hour accumulation exceeded the thermal constant and were held for
observation at 2C (well below the DZ for egg development). The number
of degree-hours accumulated between sunset (onset of oviposition) and
plant sampling are listed in Table 5.3. In 1981, the accumulated
degree-hours exceeded 153.27 on two dates (208 and 229) and were very
close to the thermal constant on 7 of the remaining 13 sample dates
(Table 5.3). With experience gained in 1981, plants were removed from
the field in 1982 at an earlier time; consequently, most of the
accumulated degree-hours were well below the thermal constant (Table
5.3).
At least two factors could have affected egg density estimates:
(1) non-viable eggs and (2) egg mortality. All light-green eggs
collected during the first day of sampling were examined for viability
as indicated by the occurrence of speckling. All eggs speckled and
hatched, indicating that females laid only viable eggs. The presence of

123
Table 5.3. The total number of degree-hours accumulated
between sunset (onset of oviposition) and
plant sampling during each sample date in
1981 and 1982. Mean number of degree-hours
required for speckling to occur in VBC eggs
is 153.27.
1981
1982
Julian
Accumulated
Julian
Accumulated
Date
Degree-Hours
Date
Degree-Hours
204
124.1
186
96.4
208
161.3a
190
102.5
211
123.8
193
106.7
215
144.3
197
123.9
218
146.5
200
125.8
222
144.3
204
123.3
225
141.3
207
138.3
229
155.5a
211
131.1
232
140.8
214
144.3
236
143.8
218
93.6
239
140.3
221
118.3
243
128.4
225
112.6
246
132.8
228
117.6
250
113.8
232
107.5
257
11.5
235
125.8
239
111.4
242
105.2
246
118.0
249
107.9
253
100.3
256
110.5
260
109.1
263
116.4
267
91.9
270
75.0
274
85.0
277
118.9
281
104.3
284
115.0
288
23.2
a
Accumulated degree-hours
exceeded
153.27.

124 -
non-viable eggs would have yielded inflated estimates of egg density (as
both viable and non-viable eggs are initially the same color) and
strongly biased adult-to-egg conversions in the oviposition model (see
Chapter VI). With regard to mortality, previous studies (Elvin 1983)
allowed for the assumption that mortality of freshly-laid eggs at night
was minimal.
Mean densities of freshly-laid VBC eggs per .91 m-row in 1981 and
1982 are shown in Fig. 5.3. In 1981, egg density displayed a general
rise from late July (date 204) to mid-September (date 257). In 1982,
egg density demonstrated a general rise and fall through the season,
with two exceptions: (1) unexplainable drops in density occurred on
September 3 and 6 (dates 246 and 249) and (2) the wide confidence
interval at date 264 resulted from sampling a plant with 78 eggs. Why
there were so many eggs on this plant is unknown. Egg and adult
densities in both years tended to change synchronously (see Chapter IV).
Sample size, sample unit size, mean, and standard deviation of freshly-
laid eggs for all sample dates are listed in Appendix F.
Egg-Speckling Hypothesis
Speckled VBC eggs may be colored cryptically as a result of the
selective pressures of predators and parasites. Light-green eggs are
easy to see on soybean, while speckled eggs are extremely difficult to
see. Light-green eggs laid during early scotophase speckle just after
sunrise and probably are difficult for predators to see. Light-green
eggs laid during late scotophase are still light-green after sunrise and
probably are easy for predators to see. Females that oviposit in early
scotophase should demonstrate a higher reproduction fitness over females
that lay eggs in late scotophase because (hypothetically) the sooner an
egg is laid after sunset the greater its chances of survival from

MEAN EGG DENSITY MEAN EGG DENSITY
125
Figure
A.
15 -
10
hh
170 180 190 200
210 220 230 240 250 260
JULIAN DATE (1981)
35
B.
30 -
25 -
20 -
10
* i* r ? *,
}i
i i i Tj
170
180 190 200
210 220 230 240 250 260 270 280 290
JULIAN DATE (1982)
5.3. Mean densities per .91 m-row ( 95% confidence interval) of
freshly-laid VBC eggs on soybean at the Green Acres
Research Farm, Alachua County, FL: (A) 1981, and (B) 1982.

126 -
predation. Evidence supporting this hypothesis can be found in Gregory
(see Chapter III), Greene et al. (1973), and Wales (1983), all of whom
found that the majority of oviposition occurs in the early hours of
scotophase.
Conclusions
Velvetbean caterpillar eggs are polychromatic, which accounts for
the wide variation of color descriptions found in the literature. Color
changes associated with egg development are temperature-dependent and
can be used to age eggs and to determine when to sample for eggs. Eggs
can be sampled readily, but care must be taken as to the time of egg
sampling if eggs are to be aged. Typically, three days will be required
to collect and process any given egg sample. Also, controlled
environmental facilities (for holding plants and eggs at cool
temperatures) are required to "suspend" egg development. The number of
VBC eggs deposited on any given night can be determined using the
methods presented in this study. These methods might be useful also in
studies of other moth species (e.g., Heliothis spp.) with polychromatic
eggs. Estimates of egg density (per night) would have been impossible
without knowledge of the temporal occurrence of oviposition (see Chapter
III). Collection of egg density data represented the final experimental
data needed for model construction. These data were essential for
comparison between model predictions and field estimates (see Chapter
VI).

CHAPTER VI
A MODEL OF VELVETBEAN CATERPILLAR ADULT
AND EGG POPULATIONS
Introduction
Crop/plant models can be used "to simulate the dynamics of a crop
and pests in a single field so that decisions can be made regarding pest
management and other production practices for that field" (Stimac and
O'Neil 1985, p. 323). One such crop/pest model is the Soybean
Integrated Crop Management (SICM) model (Wilkerson et al. 1982, 1983).
This model is composed of an aggregate of submodels that describe the
physiology of soybean growth in the presence or absence of abiotic and
biotic stresses. The model is designed to allow the user to study
various crop production and pest management strategies at the field
level for different weather patterns, cultural practices, and insect
pest scenarios.
One of the SICM submodels represents the population dynamics of
velvetbean caterpillar (VBC), a major defoliating pest of soybean
(Herzog and Todd 1980, Wilkerson et al. in press). Simulations with
SICM and the VBC submodel demonstrate that changes in the pattern
(timing and magnitude) of adult VBC influx and subsequent oviposition,
result in dramatic differences in soybean yield and net profit (see
Table 1.1). Adult and egg densities in the model were determined from
estimated larval densities. Larval densities at time "t" were used to
determine egg and adult densities at time "t-1" by calculating the adult
and egg densities required to produce the measured larval densities at
127

128 -
time "t"; field estimated mortality values for eggs were used in the
calculations. No direct estimates of adult and egg densities existed
prior to the present study. Knowledge of adult influx patterns and
ovipositional capacities within soybean fields is necessary to be able
to adequately model VBC dynamics in soybean. The goal of the present
study is to describe the relationship between VBC adult and egg
densities in soybean and to construct a model that simulates changes in
VBC egg density.
Model Objective
The model objective is to mimic VBC egg density in a soybean field.
The behavioral criterion of this objective is to simulate changes in the
density of VBC eggs in .91 m-row of soybean within the 95% confidence
intervals of field estimates. Field estimates of egg density were made
twice-a-week. Inputs into the model include (1) the number of adult
females caught in a blacklight trap, (2) soybean field size, and (3)
soybean phenological stage.
Data Requirements for Model Construction and Validation
Model construction and validation are based on data collected at
the Insect Population Dynamics Laboratory (1980-84) of the University of
Florida, and at the Green Acres Research Farm (1980-82) near
Gainesville, FL. At the farm, data were collected in a 1 ha soybean
field (cv. Bragg, see Appendix A for agronomic details and soybean
phenological stages). The temporal resolution of the model is daily but
model output is compared to field data taken at twice-a-week intervals.
The spatial resolution of the model is a soybean field and is set by
specifying the number of rows and row length in the soybean field.
Daily temporal resolution was selected so that the number of
females caught on a particular night in the blacklight trap could be

129 -
"compared" with the number of eggs laid during that same night and
because the VBC submodel in the SICM model operates on a daily
resolution. Construction on the same temporal and spatial resolution as
the VBC submodel was necessary if the adult egg population model is to
be incorporated into the dynamics model. Sampling and manpower
constraints restricted the estimation of field egg density to
twice-a-week intervals. Consequently, model predictions of egg density
are compared to field estimates at twice-a-week intervals. Data
required for model structure, determination of parameters, comparison of
model behavior, and validation were acquired from the completion of nine
separate experiments in the following areas:
(1) adult identification (see Appendix B),
(2) observation of adult behavior in the field (see Chapter III),
(3) relative estimates of adult density (see Chapter IV),
(4) absolute estimates of adult density (see Chapter IV),
(5) female reproductive states (see Chapter IV),
(6) egg identification (see Appendix E),
(7) egg developmental rate (see Chapter V),
(8) absolute estimates of egg density (see Chapter V), and
(9) monitoring of various environmental variables (see Chapters
III, IV, and V).
Sampling for adults would have been impossible without proper adult
identification. Behavioral observations of adults in the field revealed
temporal patterns in flight and oviposition. Knowledge of these
patterns was necessary for the development of adult and egg sampling
methodologies and for the acquisition of adult and egg density

130 -
estimates. Relative and absolute estimates of adult densities were
collected in 1981 and 1982 and were used for model construction,
parameterization, and model validation. Dissection data of adult
females indicated that the majority of females in the field were
potentially highly reproductive. These data were used to estimate the
proportion of mated females in the field. Proper identification of VBC
eggs and knowledge of egg developmental rate stipulated explicitly the
temporal occurrence of egg sampling and allowed for the determination of
absolute density estimates of freshly-laid eggs in the field (see
Chapter V). Freshly-laid eggs were one day old or less.
Model Assumptions
Model assumptions are listed below:
(1) There is a linear relationship between the total number of females
captured in the blacklight trap and the total number of females in
the field.
(2) All females are able to mate.
(3) There is no mortality of mated females prior to oviposition.
(4) There is no mortality of eggs during the first day after
oviposition.
(5) Ovipositional rate is the same for all females.
(6) Ovipositional rate is influenced by soybean phenological stage.
(7) Site-specific environmental conditions do not influence capture of
adults in the blacklight trap.
Model Conceptualization
A conceptual model of adult and egg dynamics is shown in Fig. 6.1.
A series of state variables are represented by acronyms shown in boxes
in Fig. 6.1. The state variables represent the numbers of individuals

131
Figure 6.1. Flow diagram of a model of VBC adult and egg populations in
a soybean field. See the text for an interpretation of
this diagram.

132 -
of a particular VBC stage that occur within a soybean field over any
given 24 h period. Arrows between boxes represent the flow of
individuals from one state variable to the next. During each time step
of the model, the total number of females captured in the blacklight
trap (FBLT) is converted to the total number of females in the field
(FTOTAL); all females are assumed to be mated. After female mortality
has been imposed, total egg density (TEGG) is calculated by multiplying
the total number of females and ovipositional rate. The "broken-line"
arrow between FTOTAL and TEGG indicates that the transfer of numbers
between the state variables is not an additive process but a
multiplicative process. A conversion function (PEGG) is used to predict
mean egg density per .91 m-row of soybean.
Model Structure
The model was written in SAS,* which provides tools for information
storage and retrieval, data modification, programming, report writing,
statistical analysis, and file handling. The SAS program and data files
are listed in Appendix G. SAS was operated at the University of Florida
on an IBM 3090, Model 200. Model output is discrete and model functions
are deterministic. Functions used in the model are concerned with (1)
the conversion of the total number of females captured in the BLT into
the number of females in the field, (2) the total number of mated
females in the field, (3) female mortality, (4) the total number of eggs
laid per female, (5) the total number of eggs laid in the field, and (6)
the predicted mean number of eggs per .91 m-row of soybean. Each of
these functions are described below.
*SAS User's Guide: Basics, and SAS User's Guide: Statistics, can be
obtained from SAS Institute Inc., P. 0. Box 8000, Cary, North
Carolina, 27511-8000, 919/467-8000.

133 -
Function for Total Female Population
The total number of females captured in the blacklight trap is
converted into the field density of females based on the following
linear regression equation:
FTOTAL = 134.11 + 23.20 (FBLT),
where FTOTAL is the total number of females in the field, FBLT is the
total number of females captured in the blacklight trap, and 134.11 and
23.20 are the intercept and slope coefficients estimated from linear
least squares. The parameters were estimated using data collected
during 1982 at the Green Acres Research Farm (see Chapter IV for details
on data collection and analysis).
Functions for Mated Female Population and Mortality
Mated female population (M ) is determined with the following
r
function:
M = (FTOTAL) (l-VjCl-MORT),
r l4
where FTOTAL is the total number of females in the field, V is the
F
proportion of virgin females in the population and MORT is the
proportional mortality of mated females per night. The quantity (1-V )
is the proportion of mated females and the quantity (1-MORT) is the
proportional survival of mated females.
In the current version of the model, values for V and MORT are
F
assumed to be zero. There are several reasons why these variables are
set to values of zero. First, both can act in a compensatory fashion in
the present model form. Secondly, data on the number of virgin females
in the population are available only for 1981. These data values are
near zero during most of the field season. Thirdly, there are no data
on mortality estimates of adult females in the field. The current model
version has been used to identify these data deficiencies.

134 -
Functions for Oviposition
Ovipositional rate (OVI) is represented in two ways: (1) by a
constant, and (2) by a variable. OVI is the total number of eggs
oviposited per female per night in the field. In the first function,
OVI is set at a constant value of 220. This value yielded more adequate
model behavior than other constant values (see below). Also, this value
was less than the highest ovipositional rate reported in the literature
(see Olivera 1981). In the second function, OVI is variable:
r
0
if
1
<
SOY
<
5
40
if
5
<
SOY
<
9
220
if
9
<
SOY
<
14
o
00
if
14
<
SOY
<
15
210
if
15
<
SOY
<
17
60
if
17
<
SOY
<
19
0
if
19
<
SOY
<
20,
V
where SOY represents the soybean phenological stage. Values of SOY were
determined by modifying the soybean phenological system developed by
Fehr and Caviness (1977)(see Table 6.1). Values of OVI for a given SOY
value were determined with model simulations using 1982 field data and
thus include the effects of all unknown variables, in addition to the
"true" phenology effect Increases in vegetative growth from VI to V9
were assigned sequentially increasing SOY values from 1 to 9. The
V-stage prior to flowering (V10 in 1982) and the first reproductive
stages (Rl, R2) were assigned the same SOY value. The remaining
R-stages were assigned sequentially increasing SOY values, except for
the R5 and R6 stages. Both of these stages lasted considerably longer

135 -
Table 6.1. Parametric values of ovipositional rate and SOY used in the
oviposition function of the adult and egg population model
of velvetbean caterpillar. Values are based on data
collected in 1982 and model simulations.
Length of3
Soybean Stage
(Days)
Soybean
Phenological
Stage
SOY Value0
Oviposition^
Rate
VE, VC
1
0
4
VI
1
0
4
V2
2
0
4
V3
3
0
3
V4
4
0
7
V5
5
0
4
V6
6
40
3
V7
7
40
4
V8
8
40
-
V9
9
40
4
V10
11
220
7
Rl, R2
11
220
11
R3
12
220
3
R4
13
220
7
Early R5
14
220
18
Mid R5
15
80
10
Late R5
16
210
7
Early R6
17
210
10
Late R6
18
60
3
R7
19
60
1
R8
20
0
A hyphen means that the corresponding soybean phenological stage must
have occurred but was not observed in the field.
See Fehr and Caviness (1977) or Tables 2.1 and 2.2 for a complete
description of these stages. In the stage descriptions "V" refers to
vegetative and "R" refers to reproductive.
c
Values of the parameter SOY were based on modifications of the Fehr and
Caviness (1977) system for determination of soybean phenological stage.
See the text for a discussion of SOY values.
Ovipositional rate is the total number of eggs oviposited per female
per night on soybean.

136 -
than the other stages (35 and 18 days, respectively) and were
partitioned into separate SOY values.
The linkage expressed between ovipositional rate and soybean
phenology in the OVI function constrains the model to give predicted egg
density values only if soybean is available. This linkage allows for
interaction between VBC and soybean. Biological justification, or
support, for the oviposition values in this function are discussed below
in the model behavior section. Use of the OVI function requires that
soybean phenological stage be converted into SOY values for each
simulated data set.
Function for Total Egg Number
The total number of eggs in the field (TEGG) is represented by the
function:
TEGG = (M )(OVI),
r
where M and OVI are the same as described earlier.
r
Function for Predicted Egg Density
The predicted mean number of eggs laid per .91 m-row of soybean
(PEGG) is represented by the function:
PEGG = TEGG/ROW,
where TEGG equals the total number of eggs laid in the field and ROW
equals the total number of .91 m-row of soybean in the field.
Model Behavior
Although all models are an abstraction of reality, their behavior
should be consistent with observations made on the real system (Stimac
1977, Overton 1977). Desired model behavior can be specified explicitly
in the behavioral criteria of a model objective. The degree to which a
model meets these behavioral criteria dictates how well model

137 -
performance is validated against the real system (Stimac 1977, Overton
1977).
The model objective of the present study is to mimic VBC egg
nightly density in a soybean field. The behavioral criterion of this
objective is to simulate densities of VBC eggs per .91 m-row of soybean
within 95% confidence intervals of field estimates made at twice-a-week
intervals. The model inputs are (1) adult female density from a
blacklight trap, (2) field size, and (3) soybean phenological stage.
The goal of the present behavioral analysis is to obtain desired model
behavior with 1982 egg density data (i.e., mimic field estimates of egg
density) and to validate model behavior against the 1981 field estimates
of egg density. Several simulations were conducted to accomplish this
goal.
Simulation of 1982 Egg Population with a Constant Ovipositional Rate
Initial simulations with the model were made with constant nightly
ovipositional rates that did not exceed rates reported in the literature
(see Moscardi et al. 1981b, 1981c, Olivera 1981, Olivera et al. 1984).
A rate of 220 eggs per female per night yielded the most appropriate
model behavior, but this behavior was deemed inadequate as only 12 of 34
predicted values fell within the 95% confidence intervals of the
estimated field densities (see Fig. 6.2). The upper and lower values of
the confidence intervals are represented in Fig. 6.2 as hypens.
Predicted values tended to fall outside of the confidence intervals in
groups, indicating that a variable ovipositional rate might provide more
adequate behavior.
Simulation of 1982 Egg Population with a Variable Ovipositional Rate
Model behavior was explored with an ovipositional rate that varied
with soybean phenological stage. Model behavior was deemed adequate

MEAN EGG DENSITY
Figure 6.2. Kean velvetbean caterpillar egg density per .91 m-row of soybean during 1982 in a 1 ha
field at the Green Acres Research Farm, Alachua County, FL. Estimated density with 95%
confidence intervals determined from field collected data. Upper and lower values of the
confidence intervals are represented as hypens. Predicted density determined with model
simulations. Ovipositional rate was a constant during the simulation.
138

139 -
with this function because 31 of 34 predicted values fell within the 95%
confidence intervals of the estimated field densities for 1982 data (see
Fig. 6.3). The three predicted values that fell outside the confidence
intervals occurred on dates when blacklight trap catch numbers were two
to nine times higher or lower than "expected". A five-day moving
average was used to determine "expected" blacklight trap catch values*.
Use of the "expected" values placed predicted egg densities within their
respective 95% confidence intervals. Why the number of captured females
was higher or lower than expected is unknown. Frequent daily
fluctuations in predicted egg density during the field season (see Fig.
6.3) were caused by numerical fluctuations in BLT catch, as all other
variables were held constant (or changed slowly) in the model.
The rationale for determining the variable ovipositional rate is
specified as follows. Ovipositional rate was set equal to zero during
the early stages of soybean growth (VE to V5) when adult and egg
densities were zero or very low. Based on field data* females were in
the area of the soybean field during early soybean growth but were not
ovipositing in the field (see Chapter IV). As soybean grew vegetatively
(V6 to V9), adult and egg densities increased and ovipositional rate was
set to a value of 40 eggs per female per night. From approximately
soybean flowering (V10) to beginning pod maturity (early R6), a high
ovipositional rate (OVI = 220 or 210) provided adequate model behavior
except for an 18 day period when ovipositional rate had to be reduced to
80 eggs per female per night. Evidently, from flowering to early pod
*A five-day moving average is calculated by determing the mean of five
days: the date of interest and the two days before and after the date
of interest. Expected values were 5.2 (date 218), 77.8 (date 253), and
26.4 (date 270).

Figure 6.3. Mean velvetbean caterpillar egg density per .91 m-row of soybean during 1982 in a 1 ha
field at the Green Acres Research Farm, Alachua County, FL. Estimated density with 95%
confidence intervals determined from field collected data. Upper and lower values of the
confidence intervals are represented as hyphens. Predicted density determined with model
simulations. Ovipositional rate was variable during the simulation.
140

- 141
maturity, females "preferred" to lay large numbers of eggs on soybean,
with the one exception already mentioned. During late pod maturity,
soybean began to senescence and adult and egg densities declined.
Presumably, females found soybean less attractive for oviposition at
this time; consequently, ovipositional rate was set to 60 eggs per
female per night. At full pod maturity (R8) when most foliage had
senesced, eggs were not present in the field, so the ovipositional rate
was set equal to zero. Females apparently will not oviposit on
senescent soybean foliage, which is to their selective advantage as
eclosed larvae would die for lack of suitable host plant material.
The reason for the necessary decline in ovipositional rate from 220
to 80 eggs per female per night during SOY 15 (or R5) is unknown but at
least two explanations are plausible. Perhaps the adult-density
conversion function acts inappropriately at SOY 15 (or R5). This seems
unlikely as the function works well in simulations with data from 1981
(see below). Perhaps females altered their ovipositional rate in
response to an environmental variable. A high daily vapor pressure
deficit (VPD) in the field from dates 240-248 may have been the
environmental factor that affected ovipositional rate in the field and
led to the calculated value of 80 eggs per female per night [see Fig.
4.7(B)], One might anticipate that future model versions use the rate
of 210 or 220 eggs per female per night from R1 to R6, or use a function
that varies ovipositional rate with VPD.
Why or if ovipositional rate in the field varies throughout the
season in response to soybean phenological stage (as depicted in the
model) is unknown. If it does occur, it may be induced by changes in
leaf area, in VPD, in biochemical changes in the soybean, or by changes
in VBC demographics. A great diversity of stimuli are known to

142 -
influence the behavior of ovipositing insects (see Hinton 1981). "Among
species that do not practice any form of parental care following egg
deposition, proper egg placement is particularly crucial. In the final
stages of site selection considerable time and energy may be spent on
fine discriminations regarding a wide variety of factors related to food
availability, food suitability, and predator pressures." (Matthews and
Matthews 1978, p. 404). For example, adult females of the noctuid moth
Autographa precationis (Guenee) prefer to oviposit on soybeans over
dandelions apparently because soybean leaf shape is a more effective
oviposition stimulus; however, larvae demonstrate a marked feeding
preference for dandelions (Kogan 1975). In another example, Heliconius
butterflies in the Neotropics spend considerable time inspecting host
plants prior to oviposition, apparently searching for Heliconius eggs or
larvae because larvae are cannibilistic (Gilbert 1975). Finally,
pipevine swallowtail butterflies, Battus philenor (Linnaeus), select
host plants largely in response to leaf shape cues (Papaj and Rausher
1983).
Simulation of 1981 Egg Population with a Variable Ovipositional Rate
Quantitative validation of model behavior was attempted by
comparing simulated egg density with 1981 field estimates.
Ovipositional rates and other parameters were determined with
experimental data and model simulations from 1982. Data specific to
1981 (i.e., soybean phenological stage and field size) were incorporated
into the 1981 model structure. Simulations depicted in Fig. 6.4, show
that 15 of 23 (65%) predicted egg density values fell within 95%
confidence intervals of field estimates. The six disagreements between
predicted and estimated values from dates 197 to 218 indicate that

MEAN EGG DENSITY
Figure 6.4. Mean velvetbean caterpillar egg density per .91 m-row of soybean during 1981 in a 1 ha
field at the Green Acres Research Farm, Alachua County, FL. Estimated density with 95%
confidence intervals determined from field collected data. Upper and lower values of the
confidence intervals are represented as hyphens. Predicted density determined with model
simulations. Ovipositional rate was variable during the simulation.
143

144 -
oviposition was depressed early in the 1981 season. Why is unknown, but
rainfall in early 1981 was very low and retarded soybean growth (see
Appendix A and Table 4.2). Perhaps VBC ovipositional rate was altered
in response to poor soybean growth or high VPD which would occur in a
drought-stressed crop. Field VPD in the day was very high during dates
200-210 and dropped below 4 mm Hg by date 216 [see Fig. 4.6(B)],
The two disagreements between predicted and estimated values at
dates 243 and 250 reflect a general depression in predicted egg density
from dates 243 to 256 (or R5). This depression resulted from an
ovipositional rate of 80 eggs per female per night as determined from
1982 model simulations. Replacement of this rate with 200 eggs per
female per night yields more acceptable behavior. Evidently, something
depressed ovipositional rate in the field during R5 in 1982 but not in
1981.
Conclusions
Addition of the adult and egg population model into the VBC
dynamics model would make the dynamics model more realistic. Equations
that describe adult and egg numbers in the current dynamics model are
based on relationships that were determined with estimated larval
densities. Therefore, changes in larval density are based on
assumed changes in adult influx. If larval densities are actually
sensitive to adult influx then changes in adult influx must be
demonstrated with experimental data and equations must be written that
are based on these data. These equations would add more realism to the
dynamics model.
Differences in model behavior between 1981 and 1982 indicate that
structural modifications with the model would be needed to achieve more

145
desirable model behavior. These modifications could be made with any or
all of the following functions: (1) total female number, (2) mated
female number, (3) mated female mortality, and (4) ovipositional rate.
Those functions that describe total female number and ovipositional rate
would appear to be the most important functions to modify, as
simulations revealed that the model was sensitive to changes in the
values of these functions. Experimental evidence of a variable
ovipositional rate should be gathered and quantified, particularly with
reference to VPD. Also, further examination of the function that
describes total female number may reveal that the mathematical
description of this function could be described more adequately with a
mechanistic representation. Collection of additional adult density
estimates with the BLT and the adult trap-cage would provide a more
complete data base for determination of the mathematical form of this
function and for determination of what variables might affect this
function. Use of a constant or a function to describe the proportion of
mated females and mated female mortality, based on field collected data,
might provide more adequate model behavior.
The present model has limited applicability as it is a site-
specific model based on two years of data; however, incorporation of
this model into the VBC dynamics model would allow for larval densities
to be predicted with BLT catch. Ultimately, the prediction of larval
densities with BLT catch could be used to eliminate scouting for larvae
in fields until adult populations reach some predetermined density. The
acquisition of additional data on adult and egg numbers from different
years would allow for model analysis, improvements and refinements.
Overall, the establishment of the quantitative relationship between

146 -
adult and egg populations with the current model represents an
accomplishment that many researches have aspired for but have not
obtained.

CHAPTER VII
SUMMARY AND CONCLUSIONS
Simulations with the Soybean Integrated Crop Management (SICM)
model (and its VBC dynamics submodel) served as both a guide and
template for present studies. These simulations indicated that changes
in the pattern of adult VBC influx (i.e., timing and magnitude) resulted
in dramatic differences in soybean yield and profit (see Table 1.1).
Adult and egg numbers used in these simulations were determined from
estimated larval densities, as data on numbers of adults and eggs were
not available. Consequently, equations that describe adult and egg
numbers in the current VBC dynamics model are based on assumed
relationships. Replacement of these equations with others based on
field collected data would probably add more realism to the dynamics
model and allow for the ability to predict economically damaging larval
densities with the use of adult density data.
The present study was conducted to estimate and model populations
of VBC adults and eggs. The objective of this model was to mimic VBC
egg densities in a soybean field within 95% confidence intervals of
estimated means. To accomplish this objective, experiments were
conducted to understand or quantify the following:
(1) adult moth identification (see Appendix B),
(2) adult behavior in the field (see Chapter III),
(3) relative estimates of adult density (see Chapter IV),
(4) absolute estimates of adult density (see Chapter IV),
147

148 -
(5) female reproductive states (see Chapter IV),
(6) egg identification (see Appendix E),
(7) egg developmental rates (see Chapter V),
(8) absolute estimates of egg density (see Chapter V), and
(9) the impact of various environmental variables on adult and egg
dynamics (see Chapters III, IV, and V).
Summary and conclusion sections for each of these experiments are
presented in respective chapters; Appendices B and E contain appropriate
discussion sections. These sections will not be repeated here in their
entirety, but important results will be discussed and highlighted in
respective order.
Adult VBC are similar in morphological appearance to another
noctuid moth, Mods latipes Guenee. Differences and similarities
between these two species are presented in Appendix B and should be
useful information to researchers encountering both (e.g., both are
caught in blacklight traps). Proper identification of VBC adults was
necessary in the present study for acquisition of data on VBC adult
numbers.
The role of the behavioral ecology study in the present work cannot
be overemphasized. Observations of adult behavior were quantified and
revealed temporal patterns in flight, mating, oviposition, and feeding.
Flight occurred primarily at night. During the day, adults resided in
the field but only after the soybean canopy had begun to close or was
closed. During the day adults flew only when disturbed or rarely if
feeding. Approximately 96% of all oviposition occurred within the first
six hours of scotophase.
Knowledge of the temporal occurrence of adult flight and residency
in the field allowed for the development of a unique adult sampling

149 -
methodology (an adult trap-cage) and the acquisition of adult density
data. Model construction and validation required these adult density
data. Knowledge of the temporal occurrence of oviposition allowed for
the development of a unique egg sampling methodology, the determination
of egg age and the acquisition of egg density data. Egg density was
determined for eggs that were less than 24 h old because model
construction and validation required data on the number of eggs
oviposited in the field on a particular night.
Estimates of adult density were obtained with a blacklight trap
(relative density) at nightly intervals and an adult trap-cage (absolute
density) at weekly intervals. These estimates represented the first
quantitative assessment of adult dynamics within a soybean field. Adult
appearance (or density) in the field, as measured with a blacklight trap
(BLT), coincided with the appearance of eggs and demonstrated that adult
density can be monitored with a BLT and that a BLT is sensitive to adult
capture at low densities. Placement of the BLT in the field was
necessary to achieve this sensitivity. Dissection of adult females
caught in the BLT in 1981 revealed that most females during the season
were mated and potentially highly reproductive. Early in the field
season, mated females that flew into the field contained large amounts
of fat body, indicating that these females probably completed their
larval development on nearby hosts. In the model, all females were
mated and had reproductive rates that did not exceed literature-reported
values.
Select physical variables were explored with multiple linear
regression for their effect on blacklight trap catch. No consistently
adequate correlations among these variables and BLT catch were
uncovered, suggesting that there are no simple linear relationships

150 -
among these variables. Use of correlation techniques may be inadequate
for predicting changes in VBC adult trap catch. A mechanistic model may
be required for the prediction of these changes.
The adult trap-cage provided data on the absolute density of adults
that was not obtainable with other techniques. An adult flushing
technique* was tried in 1980 but was considered inadequate because
adults of VBC and M. latipes could not be identified separately while in
flight. Based on data obtained with the trap cage, females established
residency in the field before males, as both sexes were caught in the
BLT prior to female residency. Adult residency appeared to be delayed
until an appropriate humidity level (5 mm Hg) had been reached in the
field during the day. Adult departure from the field, as soybean
senesced, apparently was not affected by the same humidity level. To
assess the true impact of humidity on VBC dynamics will require
extensive experimentation in the field on a year-round basis in both
soybean and other hosts, as well as the completion of detailed
laboratory experiments.
Relative and absolute estimates of adult density were calibrated
with a linear regression equation. This equation was used in the model
structure to predict the number of adults in the field based on BLT
catch. In its present form, the calibration equation is static because
it changes value only if BLT catch changes. Values of this equation
could be modified by mechanistic equations that describe the impact of
environmental variables on adult capture in a blacklight trap (e.g., the
effect of wind speed on adult flight).
*See Pedigo (1980) for a discussion of this sampling method.

151
Velvetbean caterpillar eggs are similar in morphological appearance
to a number of other lepidopteran eggs found on soybean. Differences
and similarities among these eggs are discussed in Appendix E and should
be useful information to researchers encountering these eggs. Accurate
identification of VBC eggs is necessary to sample and measure egg
density.
Velvetbean caterpillar eggs are polychromatic and change color
during development. The appearance of these different colors is
temperature-dependent and was used to age eggs. Determination of the
mean number of eggs oviposited per 0.91 m-row in soybean per night was
possible only after the acquisition of knowledge on the temporal
occurrence of oviposition and the establishment of a sampling time based
on the temperature-dependent color changes of eggs. This approach
avoided the problem of indiscriminately partitioning VBC eggs into
various age categories as model construction and validation required
data on the number of eggs oviposited in the field on a particular
night. Egg density data collected in 1982 were necessary for model
construction and determination of parametric values, while egg density
data from 1981 served for model validation.
Egg densities predicted by the model were more accurate with a
variable ovipositional rate as opposed to a constant rate. The variable
ovipositional rate was linked to changes in soybean phenology and
allowed for interaction between VBC and soybean. In model validation,
65% of the model's predicted values fell within the 95% confidence
intervals of the 1981 field estimates. Differences between predicted
and estimated values were attributed to unpredictable fluctuations in
BLT catch and to variation in ovipositional rate between years. The

152 -
variations in ovipositional rate appeared to be related to higher than
normal canopy VPD caused by drought periods.
Differences in model behavior between 1981 and 1982 indicated that
structural modifications in the model should produce more desirable
model behavior. Model behavior should be improved by writing
mechanistic equations that account for fluctuations in BLT catch and
variation in ovipositional rate. Attainment of these mechanistic
equations will depend on the collection of additional data on adult and
egg numbers and on identification and quantification of those
environmental variables that affect BLT catch and oviposition. For
example, wind tunnel tests could be used to quantify the impact of wind
speed on adult flight. Also, experimental evidence of a variable
ovipositional rate should be acquired and quantified.
The adult and egg population model developed in this study should
be incorporated into the VBC dynamics model, as equations that describe
adult influx in the dynamics model are not based on field collected
adult density estimates. Determination of the robustness of the
population model awaits the collection of additional data on adult and
egg numbers and an evaluation of the model's behavior with these data.
These data should be collected at numerous sites to examine variation in
the effect of site specific environmental conditions. Also, an analysis
of model behavior with the model as part of the overall dynamics model
should be completed.
Overall, the present study has provided the framework, manifested
as a model, necessary to measure the intra-field dynamics of a noctuid
moth. This framework can serve as template for other researchers who
seek to develop a quantitative relationship between adult and egg

153 -
populations. In the past, numerous researchers have attempted
unsuccessfully to establish such a relationship.

APPENDIX A
AGRONOMIC PRACTICES AND SOYBEAN PHENOLOGICAL-STAGES

155
Table A.l. Agronomic practices from 1980-1982 in a soybean field at Green Acres Research Farm, Alachua
County, FL.
Year
Description
1980
1981
1982
Field Size (ha)
.88
.82
.87
Number of Rows
112
102
110
Row Length (m)
103.35
107.00
103.66
Previous Winter Cover Crop
Unknown
Rye Grass
Rye Grass & Lupine
Pre-Plant Herbicide (ml/ha)
585, Surflan
585, Treflan
1169, Treflan
877, Lexone
877, Sencor
877, Lexone
Muriate of Potash (kg/ha)
258
111
104
Planting Date
June 3
June 12
June 9
Soybean Variety
Bragg
Bragg
Bragg
Row Spacing (m)
.76
.76
.76
No. of Plants/.91 row-m,
Sample Date
10, June 3
28.267, July 24
12.733, August 9

Table A.1 (continued)
Cultivation
Irrigation
Harvest Date
Seed Moisture
Yield (kg/ha)
July 9, Sweeps
June 4, 5 cm
(%)
October 17
10.7
901.1
July 13, Sweeps
July 14, Rolling
July 23, Rolling
July 21, Rolling
June 12, 5 cm
June 9, 1.3 cm
July 29, 5 cm
October 14
October 22
13
10.7
1303.6
2030.3
156

157
Table A. 2. Soybean phenological stages in an ca. 1 ha field in 1981
at the Green Acres Research Farm, Alachua County, FL;
phenological stages were not determined in 1980. Sample
size was 70 plants per sample date. Plants were staged
according to the methods of Fehr and Caviness (1977).
Calender
Date
Julian
Date
Vegetative
Stage
Reproduct
Stage
June 22
173
VC
25
176
VI
-
29
180
V2
-
July 6
187
V3
-
9
190
V4
-
13
194
V5
-
16
197
V6
-
20
201
V7
-
23
204
V7
-
27
208
V8
-
30
211
V9
Rl, R2
Aug. 3
215
V10
R2
6
218
Vll
R2
10
222
V12
R3
13
225
V13
R3
17
229
V13
R3
20
232
V13
R4
24
236
V13
R5
27
239
V13
R5
31
243
V13
R5
Sept. 3
246
V13
R5
7
250
V13
R5
14
257
V13
R5
21
264
V13
R6
29
272
V13
R7
Oct. 4
277
V13
R8
13
286
V13
R8

158 -
Table A.3. Soybean phenological stages in an ca. 1 ha field in 1982
at the Green Acres Research Farm, Alachua County, FL;
phenological stages were not determined in 1980. Sample
size varied from 30 to 70 plants, dependent upon sample
date. Plants were staged according to the methods of
Fehr and Caviness (1977).
Calender
Date
Julian
Date
Vegetative
Stage
Reproduct
Stage
June 21
172
VI
25
176
VI
-
28
179
V2
-
July 2
183
V3
5
186
V4
-
9
190
V5
-
12
193
V5
-
16
197
V6
-
19
200
V7
-
23
204
V8
-
26
207
V10
-
30
211
Vll
Rl, R2
Aug. 2
214
V12
Rl, R2
6
218
V13
R3
9
221
V13
R3
13
225
V13
R3
16
228
V14
R4
20
232
V14
R5
23
235
V14
R5
27
239
V14
R5
30
242
V14
R5
Sept. 3
246
V14
R5
6
249
V14
R5
10
253
V14
R5
13
256
V14
R5
17
260
V14
R5

159
Table A.3 (continued)
Calender
Date
Julian
Date
Vegetative
Stage
Reproductive
Stage
Sept. 20
263
V14
R5
24
267
V14
R6
27
270
V14
R6
Oct. 1
274
V14
R6
4
277
V14
R6
8
281
V14
R6
11
284
V14
R7
15
288
V14
R8

APPENDIX B
IDENTIFICATION OF ADULT Anticarsia gemmatalis Hubner
AND Mods latipes (Guenee)

Anticarsia gemmatalis Hubner
A
Wing Span
35-40 mm (Forbes 1954).
Dorsal Wing Surface
Forewing and hindwing: Basic wing coloration is extremely variable
and ranges from ashen gray to light yellowish-brown to reddish-brown
(Watson 1916a, Forbes 1954, Kimball 1965, Leppla et al. 1977). Wing
pattern is mottled and shaded, and wing-mark colorations are highly
variable and include black, white, gray, brown, and ochre [Fig. B.1(A
and C)].
Forewing: The postmedial line is distinctive and runs obliquely
from the wing apex to the approximate middle of the anal margin [Fig.
B.1(A and C), letter a]. The reniform spot on each forewing is large,
irregular, pale, and usually faint (sometimes obscure)[Fig. B.1(A and
C), letter b].
Hindwing: The postmedial line is distinctive and runs essentially
parallel to the outer margin [Fig. B.1(A and C), letter c].
Postmedial line: The postmedial line is distinctive and runs
obliquely from the apex of the forewing to the approximate middle of the
anal margin of the hindwing [Fig. B.1(A and C), letters a and c].
Ventral Wing Surface
Forewing and hindwing: Wing color is light brown or cinnamon brown
(Watson 1916a). Wing pattern is shaded and wing-mark colorations are
restricted to various shades of brown and white. The subterminal line
161

162 -
is a series of white dots that run parallel to the outer wing-margin
[Fig. B.1(B and D), letter d].
Sexual Dimorphism
Males have tufts of long setae that are present on the femora of
prothoracic legs and the tibiae of the metathoracic legs [Fig. B.l(B),
letter e]. These long setae are absent on female legs [Fig. B.l(D)]
(Anonymous 1974).
Mocis latipes (Guenee)
Wing Span
35-40 mm (Forbes 1954).
Dorsal Wing Surface
Forewing: Wing coloration is light gray, light brown, or dull
brownish-red (Hampson 1913, Forbes 1954). Wing pattern is shaded, and
wing-mark colorations are brown, gray, and grayish-brown [Fig. B.2(A and
C)]. The postmedial line is nearly parallel to the outer wing-margin
and is essentially straight, except for a slight bend just below the
costa [Fig. B.2(A and C), letter a]. The reniform spot is generally
evident, vaguely circular, and usually touches the subreinform spot
[Fig. B.2(A and C), letter b]. The subreniform spot is usually
distinct, usually circular, and may open onto the postmedial line [Fig.
B.2(A and C), letter c]. When viewed at the same time, the reniform and
subreniform spot resemble a figure eight [Fig. B.2(A and C), letters b
and c].
Hindwing: Wing coloration is light gray, light brown, or grayish-
brown [Fig. B.2(A and C)](Hampson 1913 and Forbes 1954). In general,
wing marks are vague ot absent. The postmedial line is usually present,
usually vague, and nearly parallel to the outer wing-margin [Fig. B.2(A
and C), letter d].

163 -
Postmedial line: The postmedial line of the forewing and the
hindwing form a line (sometimes vague) that parallels the outer wing-
margins [Fig. B.2(A and C), letters a and d].
Ventral Wing Surface
Forewing and hindwing; Wing color is light brown or light gray and
wing marks are vague or absent, except for the terminal line [Fig. B.2(B
and D)].
Sexual Dimorphism
Males have tufts of long setae that are present on the tibiae and
tarsi of the metathoracic legs [Fig. B.2(B), letter e]. The long setae
of the metathoracic legs can be easily seen. Long setae are absent on
female legs [Fig. B.2(D)](see Bethune 1869, Gundlach 1881, and Wolcott
1948).
Differences Between A. gemmatalis and M. latipes
The main difference between the dorsal wing surface of A.
gemmatalis and M. latipes is the placement of the postmedial line. On
A. gemmatalis the postmedial line runs obliquely from the forewing apex
to the approximate middle of the anal margin of the hindwing [Fig. B.1(A
and C, letters a and c]. On M. latipes the postmedial line of the
forewing and hindwing form a line (sometimes vague) that parallels the
outer wing-margin [Fig. B.2(A and C), letters a and d].
The main difference between the ventral wing surfaces of the two
species is the development of the subterminal line. On A. gemmatalis,
the subterminal line is a series of white dots that run parallel to the
outer wing-margin [Fig. B.1(B and D), letter d]. On M. latipes, the
subterminal line is very vague, or not present. If present, the line is
not a series of white dots [Fig. B.2(B and D)].

164 -
Differences in leg scales of the two species are evident.
A. gemmatalis, tufts of long setae occur only on the tibiae of
metathoracic legs [Fig. B.l(B), letter e]. On male M. latipes,
On male
tufts of
long setae on the metathoracic legs occur on the tibiae and the tarsi
[Fig. B.2(B), letter e].

Figure B.l. View of adult Anticarsia gemmatalis Hubner, the velvetbean caterpillar: (A) male, dorsal
view, (B) male, ventral view, (C) female, dorsal view and (D) female, ventral view.
Legend: a = postmedial line, b = reniform spot, c = postmedial line, d = subterminal line,
e = long setae on male legs. Adults collected by G. Strickland: male, 24 September 1969,
East Baton Rouge Parish, LA; female, 3 October 1970, East Baton Rouge Parish, LA. Both
specimens are on deposit at the Florida State Collection of Arthropods, Gainesville, FL.
165

Figure B.2. View of adult Mocis latipes (Guenee), striped grass looper: (A) male, dorsal view, (B)
male, ventral view, (C) female, dorsal view, and (D) female, ventral view. Legend, a -
postmedial line, b = reniform spot, c = subreniform spot, d = postmedial line, e = long
setae on male legs. Adults collected by Tom Dean (ex ova labrotorio): male and female, 31
October 1984, Alachua County, Gainesville, FL. Both specimens are on deposit at the
Florida State Collection of Arthropods, Gainesville, FL.
166

APPENDIX C
BEHAVIORAL OBSERVATIONS:
QUANTITATIVE TECHNIQUE AND DATA

A detailed explanation and an example of the quantitative
technique, for analysis of observational data on oviposition, mating,
and feeding, are presented. Data in Tables C.l and C.2 are artificial
for ease of discussion. In Table C.l, data are presented on number of
observations, observation times, and weighted observations. The
observational time of hour 1 is 30 min, and the number of observations
of the activity is 1. The weighted observation for hour 1 is .03; one
observation divided by 30 min equals .03. Six observations occur during
hours 2 and 3. Based on the number of observations for hours 2 and 3,
the activity is equally prevalent during each hour. This equality is
misleading because 60 min were required to make the observations in hour
2, while 30 min were required in hour 3; i.e., twice as much time was
spent in hour 2 to see the same number of observations. The weighted
observations for hours 2 and 3 are .10 and .20, respectively. The value
for hour 3 is twice as large as the value for hour 2. The difference
between the weighted values for the two hours properly reflects the
differences in observational time between the two hours.
In Table C.2, data are presented on weighted observations, sample
means, normalized means, and percent normalized means. Data are grouped
by hour after sunset, irregardless of year, month, and day. For hour 1,
the sample mean of the weighted observations is determined as follows:
.03 + .01 + .02 = .06/3 = .02. The sum of the sample means for all 12
hours is .82. Each sample mean is normalized by division with .82. The
normalized sample means add up to the value of one. A percent
normalized sample mean is obtained by multiplying the appropriate
normalized sample mean by 100.
168 -

169 -
Table C.l. Artificial data of an adult activity and the
technique for determination of the temporal
frequency of that activity during scotophase
calculation of the weighted observations for a
particular day.
Hour After
Sunset
Number of
Observations
Observational
Time (min)
Weighted
Observations
(obs./min)
1
1
30
.03
2
6
60
.10
3
6
30
.20
4
2
60
.03
5
1
60
.02
6
0
0
.00
7
0
0
.00
8
0
0
.00
9
0
60
.00
10
0
45
O
o

11
0
45
.00
12
0
30
.00
Weighted Observations
Number of Observations
Observational Time

170 -
Table C.2. Artificial data of an adult activity and the technique for
determination of the temporal frequency of that activity
during scotophase calculation of sample means,
normalized means, and percent normalized means with
weighted observations. Different years, months, and nights
have been combined.
Hour After
Sunset
Date3 Weighted*3
(D-M-Y) Observation
c
Sample
Mean
Normalized^
Mean
Percent
Mean
1
27-A-80
.03
.02
.0244
2.44
07-S-80
.01
20-A-81
.02
2
27-A-80
.10
.15
.1829
18.29
20-A-81
.10
14-S-82
.20
21-S-82
3
21-A-81
.25
.25
.3049
30.49
29-A-81
.30
24-S-81
.25
25-S-81
.20
4
17-S-81
.14
.16
.1951
19.51
10-S-82
.18
5
23-A-81
.11
.14
.1707
17.07
17-S-81
.17
6
23-A-81
.05
.06
.0732
7.32
13-S-81
.07
04-S-82
.06
7
13-S-81
.01
.02
.0244
2.44
04-S-82
.01
25-S-82
.04
8
13-S-81
.00
.01
.0122
1.22
25-S-81
.02
13-S-81
.01
9
13-S-81
.00
.00
.0000
0.00
24-A-82
.00
28-A-82
.00
10
21-A-81
.02
.01
.0122
1.22
25-A-81
.00

171
Table C.2 (continued)
Hour After
Date3
Weighted^
c
Sample
Normalized^
e
Percent
Sunset
(D-M-Y)
Observation
Mean
Mean
Mean
11
28-A-81
.00
.00
.0000
0.00
01-S-81
.00
04-S-81
.00
08-S-81
.00
13-S-81
.00
12
25-A-81
.00
.00
.0000
0.00
28-A-81
.00
Total
.82
1.0000
100.00
aD-M-Y = Day, Month, Year; A = August, S = September; 80 = 1980, 81 =
1981, 82 = 1982.
^For calculation of individual weighted observations see Table C.l.
c
Sample mean of weighted observations for each hour; e.g., for first
hour after sunset, sample mean = .02 = (.03 + .01 + .02)/3.
^Normalized Mean = Sample Mean/.82.
6
Percent Mean = Normalized Mean x 100.

172
Table C.3. Observation data on mating of adult velvetbean caterpillar
in a 1 ha soybean field at Green Acres Research Farm,
Alachua County, FL, 1980-82. Weighted observations are also
given.
Number of
_ a
Date
(D-M-Y)
Hour After
Sunset
Observations
of Mating
c
Observational
Time (min)
Weighted
Observations
05-A-80
1
0
49
0.000000
15-A-81
1
1
60
0.016667
19-A-81
1
0
60
0.000000
22-A-81
1
1
60
0.016667
26-A-81
1
0
60
0.000000
29-A-81
1
2
35
0.057143
02-S-81
1
0
60
0.000000
05-S-81
1
0
59
0.000000
09-S-81
1
1
49
0.020408
12-S-81
1
0
60
0.000000
17-S-81
1
1
60
0.016667
19-S-81
1
1
50
0.020000
24-S-81
1
0
60
0.000000
26-A-82
1
0
40
0.000000
03-S-82
1
3
10
0.300000
24-S-82
1
0
60
0.000000
05-A-80
2
1
60
0.016667
15-A-81
2
1
60
0.016667
19-A-81
2
0
39
0.000000
22-A-81
2
2
60
0.033333
26-A-81
2
0
30
0.000000
29-A-81
2
2
35
0.057143
02-S-81
2
1
60
0.016667
05-S-81
2
0
3
0.000000
09-S-81
2
12
28
0.428571
12-S-81
2
1
21
0.047619
17-S-81
2
4
60
0.066667

173
Table C.3 (continued)
Date3
(D-M-Y)
Hour After
Sunset
Number of
Observations
of Mating
c
Observational
Time (min)
Weighted^
Observations
19-S-81
2
0
60
0.000000
24-S-81
2
1
60
0.016667
26-A-81
2
5
60
0.083333
03-S-81
2
15
60
0.250000
24-S-81
2
0
45
0.000000
05-A-80
3
4
60
0.066667
15-A-81
3
2
35
0.057143
22-A-81
3
2
32
0.062500
26-A-81
3
1
60
0.016667
29-A-81
3
2
40
0.050000
02-S-81
3
1
15
0.066667
09-S-81
3
10
42
0.238095
12-S-81
3
4
49
0.081633
17-S-81
3
4
60
0.066667'
19-S-81
3
1
18
0.055556
24-S-81
3
0
37
0.000000
26-A-82
3
0
18
0.000000
03-S-82
3
11
40
0.275000
10-S-82
3
1
38
0.026316
24-S-82
3
0
50
0.000000
05-A-80
4
1
11
0.090909
15-A-81
4
2
50
0.040000
16-A-81
4
0
10
0.000000
22-A-81
4
0
45
0.000000
23-A-81
4
0
3
0.000000
26-A-81
4
1
36
0.027778
29-A-81
4
1
35
0.028571
09-S-81
4
5
38
0.131579
12-S-81
4
2
60
0.033333

174 -
Table C.3 (continued)
Date3
(D-M-Y)
Hour After
Sunset
Number of
Observations
of Mating
c
Observational
Time (min)
Weighted^
Observations
17-S-81
4
5
45
0.111111
19-S-81
4
3
45
0.066667
03-S-82
4
14
60
0.233333
10-S-82
4
2
60
0.033333
24-S-82
4
9
60
0.150000
16-A-81
5
0
35
0.000000
23-A-81
5
0
60
0.000000
27-A-81
5
0
33
0.000000
12-S-81
5
0
21
0.000000
17-S-81
5
0
28
0.000000
03-S-82
5
0
11
0.000000
04-S-82
5
1
19
0.052632
10-S-82
5
0
19
0.000000
24-S-82
5
1
37
0.027027
25-S-82
5
0
18
0.000000
16-A-81
6
0
55
0.000000
23-A-81
6
0
42
0.000000
13-S-81
6
2
44
0.045455
04-S-82
6
1
60
0.016667
25-S-82
6
4
60
0.066667
16-A-81
7
0
30
0.000000
13-S-81
7
1
21
0.047619
04-S-82
7
0
11
0.000000
25-S-82
7
0
3
0.000000
16-A-81
8
0
60
0.000000
13-S-81
8
0
39
0.000000
25-S-81
8
1
33
0.030303
16-A-81
9
0
60
0.000000
13-S-81
9
0
60
0.000000

175 -
Table C.3 (continued)
Number of
Date3
(D-M-Y)
Hour After
Sunset
Observations
of Mating
c
Observational
Time (min)
Weighted^
Observations
28-A-82
9
0
27
0.000000
31-A-82
9
0
24
0.000000
04-S-82
9
0
19
0.000000
07-S-82
9
0
1
0.000000
ll-S-82
9
0
11
0.000000
14-S-82
9
0
7
0.000000
18-S-82
9
0
2
0.000000
25-S-82
9
1
52
0.019231
16-A-81
10
0
45
0.000000
18-A-81
10
0
23
0.000000
21-A-81
10
0
20
0.000000
25-A-81
10
0
16
0.000000
28-A-81
10
0
13
0.000000
Ol-S-81
10
0
8
0.000000
04-S-81
10
0
4
0.000000
13-S-81
10
0
60
0.000000
28-A-82
10
0
53
0.000000
31-A-82
10
1
60
0.016667
04-S-82
10
0
51
0.000000
07-S-82
10
0
59
0.000000
ll-S-82
10
0
59
0.000000
14-S-82
10
0
60
0.000000
18-S-82
10
0
60
0.000000
21-S-82
10
0
58
0.000000
25-S-82
10
0
53
0.000000
16-A-81
11
0
48
0.000000
18-A-81
11
0
51
0.000000
21-A-81
11
0
56
0.000000
25-A-81
11
0
60
0.000000

176 -
Table C.3 (continued)
Date3
(D-M-Y)
Hour After
Sunset
Number of
Observations
of Mating
Q
Observational
Time (min)
Weighted*^
Observations
28-A-81
11
0
60
0.000000
Ol-S-81
11
0
60
0.000000
04-S-81
11
0
60
0.000000
08-S-81
11
0
60
0.000000
13-S-81
11
0
6
0.000000
15-S-81
11
0
51
0.000000
31-A-82
11
1
36
0.027778
14-S-82
11
0
8
0.000000
18-S-82
11
0
23
0.000000
21-S-82
11
0
17
0.000000
25-S-82
11
0
32
0.000000
25-A-81
12
0
2
0.000000
28-A-81
12
0
7
0.000000
Ol-S-81
12
0
14
0.000000
04-S-81
12
0
19
0.000000
08-S-81
12
0
25
0.000000
15-S-81
12
0
38
0.000000
aD-M-Y = Day, Month, Year; A = August, S = September; 80 = 1980,
81 = 1981, 82 = 1982.
b
c
d
Total number of observations of mating was 157.
Total number of observational minutes was 5162.
Number of Observations
Weighted Observations =
Observational Time

177
Table C.4. Sample mean and standard error of the weighted
observations of mating velvetbean caterpillar
adults are grouped by post-sunset hour, along with
the percent normalized sample mean and standard
error. Observations were made from 1980-82 at the
Green Acres Research Farm, Alachua County, FL, in a
1 ha soybean field.
Hour After
Sunset
a
n
Sample Mean of
the Weighted
Observations
(SE)
Percent Normalized^
Sample Mean
(SE)
1
16
.0280
.0185
9.60
+
6.36
2
16
.0646
.0288
22.15
+
9.87
3
15
.0709
.0208
24.31
+
7.13
4
14
.0676
.0183
23.19
+
6.27
5
10
.0080
.0056
2.73
+
1.94
6
5
.0258
.0132
8.84
+
4.52
7
4
.0119
.0119
4.08
+
4.08
8
3
.0101
.0101
3.46
+
3.46
9
10
.0019
.0019
.66
+
. 66
10
17
.0009
.0010
.34
+
.34
11
15
.0019
.0019
.64
+
.64
12
6
.0000
.0000
.00
+
.00
n = number of weighted observations per sample mean; n is not
the number of mating observations. See Table C.3 for complete
listing of all observations and observational times.
Percent normalized sample mean = (sample mean of weighted
observations/0.291516)*100. Percent normalized sample mean =
(standard error of sample mean/0.291516)*100.

178
Table C.5. Observational data on oviposition by adult velvetbean
caterpillar females in a 1 ha soybean field at the Green
Acres Research Farm, Alachua County, FL, 1981-82. Weighted
observations are also given.
Date3
(D-M-Y)
Hour After
Sunset
Number of
Observations
of Oviposition
0
Observational
Time (min)
Weighted^
Observations
19-A-81
1
2
60
0.033333
22-A-81
1
3
60
0.050000
26-A-81
1
1
60
0.016667
29-A-81
1
1
35
0.028571
02-S-81
1
1
60
0.016667
05-S-81
1
2
59
0.033898
09-S-81
1
0
49
0.000000
12-S-81
1
1
60
0.016667
17-S-81
1
9
60
0.150000
19-S-81
1
10
50
0.200000
24-S-81
1
0
60
0.000000
26-A-81
1
0
40
0.000000
03-S-81
1
1
10
0.100000
24-S-81
1
10
60
0.166667
19-A-81
2
1
39
0.025641
22-A-81
2
0
60
0.000000
26-A-81
2
0
30
0.000000
29-A-81
2
3
35
0.085714
02-S-81
2
1
60
0.016667
05-S-81
2
0
3
0.000000
09-S-81
2
0
28
0.000000
12-S-81
2
2
21
0.095238
17-S-81
2
2
60
0.033333
19-S-81
2
2
60
0.033333
24-S-81
2
1
60
0.016667
26-A-82
2
9
60
0.150000

179 -
Table C.5 (continued)
Number of
Date3
(D-M-Y)
Hour After
Sunset
Observations
of Oviposition
c
Observational
Time (min)
Weighted
Observations
03-S-82
2
7
60
0.116667
24-S-82
2
5
45
0.111111
22-A-81
3
0
32
0.000000
26-A-81
3
0
60
0.000000
29-A-81
3
0
40
0.000000
02-S-81
3
0
15
0.000000
09-S-81
3
0
42
0.000000
12-S-81
3
2
49
0.040816
17-S-81
3
3
60
0.050000
24-S-81
3
0
37
0.000000
26-A-81
3
0
18
0.000000
03-S-81
3
6
40
0.150000
10-S-81
3
0
38
0.000000
24-S-81
3
6
50
0.120000
22-A-81
4
0
45
0.000000
23-A-81
4
0
3
0.000000
26-A-81
4
0
36
0.000000
29-A-81
4
0
35
0.000000
09-S-81
4
0
38
0.000000
12-S-81
4
0
60
0.000000
17-S-81
4
1
45
0.022222
03-S-82
4
8
60
0.133333
10-S-82
4
4
60
0.066667
24-S-82
4
5
60
0.083333
23-A-81
5
0
60
0.000000
27-A-81
5
0
33
0.000000
12-S-81
5
0
21
0.000000
17-S-81
5
0
28
0.000000

180 -
Table C.5 (continued)
Number of
Date3
(D-M-Y)
Hour After
Sunset
Observations
of Oviposition
c
Observational
Time (min)
Weighted^
Observations
03-S-82
5
0
11
0.000000
04-S-82
5
1
19
0.052632
10-S-82
5
0
19
0.000000
24-S-82
5
0
37
0.000000
25-S-82
5
0
18
0.000000
23-A-81
6
0
42
0.000000
13-S-81
6
0
44
0.000000
04-S-82
6
1
60
0.016667
25-S-82
6
3
60
0.050000
13-S-81
7
0
21
0.000000
04-S-82
7
0
11
0.000000
25-S-82
7
0
3
0.000000
13-S-81
8
0
39
0.000000
25-S-81
8
0
33
0.000000
13-S-81
9
0
60
0.000000
24-A-82
9
0
32
0.000000
28-A-82
9
0
27
0.000000
31-A-82
9
0
24
0.000000
04-S-82
9
0
19
0.000000
07-S-82
9
0
1
0.000000
ll-S-82
9
0
11
0.000000
14-S-82
9
0
7
0.000000
18-S-82
9
0
2
0.000000
25-S-82
9
0
52
0.000000
21-A-81
10
0
20
0.000000
25-A-81
10
0
16
0.000000
28-A-81
10
0
13
0.000000
01-S-81
10
0
8
0.000000

181
Table C.5 (continued)
Date3
(D-M-Y)
Hour After
Sunset
Number of
Observations
of Oviposition
c
Observational
Time (min)
Weighted^
Observations
04-S-81
10
0
4
0.000000
13-S-81
10
0
60
0.000000
24-A-82
10
2
60
0.033333
28-A-82
10
3
53
0.056604
31-A-82
10
2
60
0.033333
04-S-82
10
0
51
0.000000
07-S-82
10
0
59
0.000000
ll-S-82
10
0
59
0.000000
14-S-82
10
0
60
0.000000
18-S-82
10
0
60
0.000000
21-S-82
10
0
58
0.000000
25-S-82
10
0
53
0.000000
21-A-81
11
0
56
0.000000
25-A-81
11
0
60
0.000000
28-A-81
11
0
60
0.000000
Ol-S-81
11
0
60
0.000000
04-S-81
11
0
60
0.000000
08-S-81
11
0
60
0.000000
13-S-81
11
0
6
0.000000
15-S-81
11
0
51
0.000000
ll-A-82
11
0
28
0.000000
31-A-82
11
0
36
0.000000
14-S-82
11
0
8
0.000000
18-S-82
11
0
23
0.000000
21-S-82
11
0
17
0.000000
25-S-82
11
0
32
0.000000
25-A-81
12
0
2
0.000000
28-A-81
12
0
7
0.000000

182
Table C.5 (continued)
Date3
(D-M-Y)
Hour After
Sunset
Number of
Observations
of Oviposition
c
Observational
Time (min)
Weighted*^
Observations
Ol-S-81
12
0
14
0.000000
04-S-81
12
0
19
0.000000
08-S-81
12
0
25
0.000000
15-S-81
12
0
38
0.000000
aD-M-Y =
Day, Month,
Year; A = August, S
= September; 81
= 1981,
82 = 1982.
^Total number of observations of oviposition was 121.
c
Total number of observational minutes was 4417.
^Weighted Observations = Number of Observations
Observational Time

183 -
Table C.6. Sample mean and standard error of weighted
observations of oviposition by female velvetbean
caterpillar grouped by post-sunset hour, along with
the percent normalized sample mean and standard error.
Observations were made from 1980-82 at the Green Acres
Research Farm, Alachua County, FL, in a 1 ha soybean
field.
Hour After
Sunset
a
n
Sample Mean
of the Weighted
Observations
( SE)
Percent
Normalized
Sample Mean
( SE)
1
14
.0580
+
.0181
29.35
9.15
2
14
.0489
+
.0138
24.72
7.00
3
12
.0301
+
.0151
15.20
7.65
4
10
.0306
+
.0150
15.45
7.60
5
9
.0058
+
.0058
2.96
2.96
6
4
.0167
+
.0118
8.43
5.96
7
3
.0000
+
.0000
.00
.00
8
2
.0000
+
.0000
.00
.00
9
10
.0000
+
.0000
.00
.00
10
16
.0077
+
.0043
3.90
2.18
11
14
.0000
+
.0000
.00
.00
12
6
.0000

.0000
.00
.00
n = number of weighted observations per sample mean; n is not
the number of ovipositional observations. See Table C.5 for a
complete listing of all observation and observational times.
Percent normalized sample mean = (sample mean of the weighted
observations/0.197760)*100. Percent normalized standard error =
(standard error of the sampled mean/ 0.197760)*100.

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
184 -
Total oviposition per female at four different
temperatures. Datum at 11.9C is from field
observation at Green Acres Research Farm, Alachua
County, FL. Data of 21.1, 23.9, and 26.7C are
from Moscardi et al. (1981b) and were stored on
computer cards at the time of this analysis in
Building 175, Insect Population Dynamics
Laboratory, University of Florida, Alachua County,
Gainesville, FL.
Total Oviposition/Female/Temperature(C)
21.1
23.9
26.7
448
1508
728
520
912
1256
428
412
1384
600
392
608
640
324
296
372
940
620
296
352
1696
348
268
664
612
540
604
472
1744
608
228
284
1872
796
440
672
744
548
596
364
1448
584
176
348
1080
732
748
936
660
460
648
468
1504
784
236
444
1360
484
356
584
572
1976
912
388
1804
528
384
560
512
1644
324
644
488

Table C.8. Observational data on feeding of adult velvetbean caterpillar in a soybean field at Green
Acres Research Farm, Alachua County, FL, 1980-82. Weighted observations are also given.
Date*
(D-M-Y)
Hour
MaleC
Agg
Male**
OAgg
Male*
All
Female^
Adult8
MKAh
Agg
HFA1
OAgg
TleJ
Weightk
1
Weight1
2
Weight
3
Weight"
4
Weight
5
Weight**
6
Weight**
7
05-A-80
1
0
0
0
0
1
1
1
49
0.000000
0.000000
0.000000
0.000000
0.020408
0.020408
0.020408
01-A-81
1
0
1
i
i
0
2
2
60
0.000000
0.016667
0.016667
0.016667
0.000000
0.033333
0.033333
05-A-81
1
0
0
0
0
0
0
0
56
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
12-A-8I
1
0
0
0
0
0
0
0
45
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
15-A-8I
1
0
1
1
i
1
3
3
60
0.000000
0.016667
0.016667
0.016667
0.016667
0.050000
0.050000
19-A-81
1
0
1
1
0
2
3
3
60
0.000000
0.016667
0.016667
0.000000
0.033333
0.050000
0.050000
22-A-8I
1
0
0
0
1
0
1
1
60
0.000000
0.000000
0.000000
0.016667
0.000000
0.016667
0.016667
26-A-8I
1
0
0
0
0
0
0
0
60
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
29-A-81
1
0
0
0
0
0
0
0
35
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
02-S-81
1
0
1
1
0
0
1
1
60
0.000000
0.016667
0.016667
0.000000
0.000000
0.016667
0.016667
05-S-81
1
0
2
2
0
4
6
6
59
0.000000
0.033898
0.033898
0.000000
0.067797
0.101695
0.101695
09-S-81
1
0
0
0
0
0
0
0
49
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
12-S-8I
1
0
0
0
0
0
0
0
60
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
I7-S-8I
1
12
0
12
0
0
12
0
60
0.200000
0.000000
0.200000
0.000000
0.000000
0.200000
0.000000
19-S-81
1
0
1
1
0
0
1
1
50
0.000000
0.020000
0.020000
0.000000
0.000000
0.020000
0.020000
24-S-8I
1
0
0
0
0
0
0
0
60
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
26-A-82
1
0
0
0
0
0
0
0
40
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
185

Table C.8 (continued)
Date3
(D-M-Y)
b
Hour
MaleC
Agg
Maled
OAgg
Male*
All
_ f
Female
Adult8
MFAh
Agg
MFA1
OAgg
Tine
03-S-82
1
0
2
2
0
,
3
3
10
24-S-82
1
0
4
4
0
5
9
9
60
05-A-80
2
0
0
0
0
4
4
4
60
Ol-A-81
2
0
0
0
0
0
0
0
60
05-A-81
2
0
0
0
0
0
0
0
IS
12-A-8I
2
0
4
4
9
0
13
13
54
15-A-81
2
0
1
1
2
4
7
7
60
19-A-8I
2
0
0
0
0
0
0
0
39
22-A-8I
2
0
0
0
2
0
2
2
60
26-A-8I
2
0
0
0
0
0
0
0
30
29-A-81
2
0
0
0
0
0
0
0
35
02-S-81
2
0
0
0
4
0
4
4
60
05-S-81
2
0
0
0
0
0
0
0
3
09-S-81
2
0
0
0
0
0
0
0
28
12-S-81
2
0
0
0
0
0
0
0
21
17-S-81
2
22
0
22
0
0
22
0
60
19-S-8I
2
9
7
16
0
0
16
7
60
24-S-81
2
0
0
0
0
0
0
0
60
26-A-82
2
0
6
6
3
0
9
9
60
Weight
3
Weight
4
Weight
5
Weight*1
1
Weight *
2
Weight** Weight**
6 7
0.000000
0.200000
0.200000
0.000000
0.100000
0.300000
0.300000
0.000000
0.066667
0.066667
0.000000
0.083333
0.150000
0.150000
0.000000
0.000000
0.000000
0.000000
0.066667
0.066667
0.066667
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.074074
0.074074
0.166667
0.000000
0.240741
0.240741
0.000000
0.016667
0.016667
0.033333
0.066667
0.116667
0.116667
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.033333
0.000000
0.033333
0.033333
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.066667
0.000000
0.066667
0.066667
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.366667
0.000000
0.366667
0.000000
0.000000
0.366667
0.000000
0.150000
0. 1 16667
0.266667
0.000000
0.000000
0.266667
0.116667
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.100000
0.100000
0.050000
0.000000
0.150000
0.150000
186

Table C.8 (continued)
Date3 MaleC Maled Male* MFAh MFA1
(D-M-Y) Hour Agg OAgg All Female Adult* Agg OAgg
03-S-82 2 0
24-S-82 2 3
05-A-80 3 0
01-A-8I 3 0
15-A-81 3 0
22-A-81 3 0
26-A-8I 3 0
29-A-81 3 0
02-S-8I 3 0
09-S-81 3 0
12-S-81 3 0
17-S-8I 3 29
19-S-81 3 5
24-S-81 3 9
26-A-82 3 0
03-S-82 3 0
10-S-82 3 0
24-S-82 3 0
05-A-80 4 0
0 0 0
2 5 5
0 0 0
0 0 0
0 0 7
1 1 0
0 0 2
4 4 0
0 0 0
0 0 0
0 0 0
0 29 0
0 5 0
0 9 0
1 1 0
0 0 1
2 2 1
7 7 6
0 0 0
0 0 0
0 10 7
3 3 3
0 0 0
1 a s
o i i
0 2 2
0 4 4
0 0 0
0 0 0
0 0 0
0 29 0
0 5 0
0 9 0
0 1 1
0 1 1
0 3 3
3 16 16
2 2 2
Time1
Uelghtk
Weight1
2
WeightBI
3
Weight0
4
Weight0
5
Weight*1
6
We ight**
7
60
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
45
0.066667
0.044444
0.111111
0.111111
0.000000
0.222222
0.155556
60
0.000000
0.000000
0.000000
0.000000
0.050000
0.050000
0.050000
8
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
35
0.000000
0.000000
0.000000
0.200000
0.028571
0.228571
0.228571
32
0.000000
0.031250
0.031250
0.000000
0.000000
0.031250
0.031250
60
0.000000
0.000000
0.000000
0.033333
0.000000
0.033333
0.033333
40
0.000000
0.100000
0.100000
0.000000
0.000000
0.100000
0.100000
15
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
42
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
49
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
60
0.483333
0.000000
0.483333
0.000000
0.000000
0.483333
0.000000
18
0.277778
0.000000
0.277778
0.000000
0.000000
0.277778
0.000000
37
0.243243
0.000000
0.243243
0.000000
0.000000
0.243243
0.000000
18
0.000000
0.055556
0.055556
0.000000
0.000000
0.055556
0.055556
40
0.000000
0.000000
0.000000
0.025000
0.000000
0.025000
0.025000
38
0.000000
0.052632
0.052632
0.026316
0.000000
0.078947
0.078947
50
0.000000
0.140000
0.140000
0.120000
0.060000
0.320000
0.320000
11
0.000000
0.000000
0.000000
0.000000
0.181818
0.181818
0.181818
187

Table C.8 (continued)
Date3
(D-M-Y)
II **
Hour
MaleC
Agg
Maled
OAgg
Male*
All
Female^
Adult8
. MFAh
*88
UFA1
OAgg
Time
15-A-8I
4
0
3
3
2
0
5
5
50
16-A-81
4
0
0
0
0
1
1
1
10
22-A-8I
4
0
4
4
5
1
10
10
45
23-A-8I
4
0
0
0
0
0
0
0
3
26-A-81
4
0
4
4
1
0
5
5
36
29-A-8I
4
0
3
3
0
0
3
3
35
09-S-8I
4
0
0
0
1
0
1
1
38
12-S-81
4
0
3
3
1
0
4
4
60
17-S-81
4
17
0
17
0
0
17
0
45
03-S-82
4
0
3
3
0
0
3
3
60
10-S-82
4
0
2
2
1
0
3
3
60
24-S-82
4
0
0
0
5
0
5
5
60
16-A-8I
5
0
2
2
4
0
6
6
35
23-A-81
5
0
i
1
4
1
6
6
60
27-A-81
5
0
0
0
2
0
2
2
33
12-S-81
5
0
0
0
0
0
0
0
21
17-S-81
5
18
0
18
1
0
19
1
28
03-S-82
5
15
1
16
1
0
17
2
n
04-S-82
5
15
0
15
0
2
17
2
19
Weight
4
Weight
5
Weight*1 Weight* Weight"
I 2 3
Weight** Weight**
6 7
0.000000
0.060000
0.060000
0.040000
0.000000
0.100000
0.100000
0.000000
0.000000
0.000000
0.000000
0.100000
0.100000
0.100000
0.000000
0.088889
0.088889
0.111111
0.022222
0.222222
0.222222
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.111111
0.111111
0.027778
0.000000
0.138889
0.138889
0.000000
0.085714
0.085714
0.000000
0.000000
0.085714
0.085714
0.000000
0.000000
0.000000
0.026316
0.000000
0.026316
0.026316
0.000000
0.050000
0.050000
0.016667
0.000000
0.066667
0.066667
0.377778
0.000000
0.377778
0.000000
0.000000
0.377778
0.000000
0.000000
0.050000
0.050000
0.000000
0.000000
0.050000
0.050000
0.000000
0.033333
0.033333
0.016667
0.000000
0.050000
0.050000
0.000000
0.000000
0.000000
0.083333
0.000000
0.083333
0.083333
0.000000
0.057143
0.057143
0.114286
0.000000
0. 171429
0.171429
0.000000
0.016667
0.016667
0.066667
0.016667
0.100000
0.100000
0.000000
0.000000
0.000000
0.060606
0.000000
0.060606
0.060606
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.642857
0.000000
0.642857
0.035714
0.000000
0.678571
0.035714
1.363636
0.090909
1.454545
0.090909
0.000000
1.545455
0.181818
0.789474
0.000000
0.789474
0.000000
0.105263
0.894737
0.105263
188

Table C.8 (continued)
Da te
(D-M-Y)
u b
Hour
MaleC
Agg
Male**
OAgg
Hale*
All
Female*
Adult8
HFA*'
Agg
HFA1
OAgg
Time
10-S-82
5
0
0
0
0
0
0
0
19
24-S-82
5
0
0
0
0
0
0
0
37
25-S-82
5
0
0
0
2
0
2
2
18
16-A-81
6
0
7
7
5
3
15
15
55
23-A-81
6
0
1
1
1
0
2
2
A2
13-S-81
6
0
0
0
0
0
0
0
AA
OA-S-82
6
0
0
0
0
0
0
0
60
25-S-82
6
0
0
0
3
0
3
3
60
16-A-81
7
0
0
0
0
3
3
3
30
13-S-81
7
0
0
0
0
0
0
0
21
OA-S-82
7
0
0
0
0
0
0
0
11
25-S-82
7
0
0
0
0
0
0
0
3
16-A-81
8
0
0
0
2
2
A
A
60
13-S-81
8
0
2
2
3
0
5
5
39
25-S-82
8
5
2
7
6
0
13
8
33
16-A-8I
9
0
4
A
3
1
8
8
60
13-S-81
9
0
0
0
2
0
2
2
60
28-A-82
9
0
1
1
1
0
2
2
27
31-A-82
9
0
0
0
0
0
0
0
2A
Weight** Weight* Weight01 Weight Weight Weight*1 Weight**
1 2 3 A 5 6 7
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.151515
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.127273
0.023810
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.051282
0.060606
0.066667
0.000000
0.037037
0.000000
0.000000
0.000000
0.000000
0.127273
0.023810
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.051282
0.212121
0.066667
0.000000
0.037037
0.000000
0.000000
0.000000
0.111111
0.090909
0.023810
0.000000
0.000000
0.050000
0.000000
0.000000
0.000000
0.000000
0.033333
0.076923
0.181818
0.050000
0.033333
0.037037
0.000000
0.000000
0.000000
0.000000
0.054545
0.000000
0.000000
0.000000
0.000000
0.100000
0.000000
0.000000
0.000000
0.033333
0.000000
0.000000
0.016667
0.000000
0.000000
0.000000
0.000000
0.000000
0. 111 111
0.272727
0.047619
0.000000
0.000000
0.050000
0.100000
0.000000
0.000000
0.000000
0.066667
0.128205
0.393939
0.133333
0.033333
0.074074
0.000000
0.000000
0.000000
0.111111
0.272727
0.047619
0.000000
0.000000
0.050000
0.100000
0.000000
0.000000
0.000000
0.066667
0.128205
0.242424
0.133333
0.033333
0.074074
0.000000

Table C.8 (continued)
Da tea
(D-M-Y)
.. *>
Hour
MaleC
Agg
Male1*
OAgg
Male'
All
Female^
Adult8
MFA*1
Agg
MFA1
OAgg
Time
04-S-82
9
0
0
0
0
0
0
0
19
07-S-82
9
0
0
0
0
0
0
0
1
ll-S-82
9
0
0
0
0
0
0
0
11
I4-S-82
9
0
0
0
0
0
0
0
7
18-S-82
9
0
0
0
0
0
0
0
2
25-S-82
9
0
2
2
8
0
10
10
52
04-A-81
10
0
0
0
0
0
0
0
30
07-A-81
10
0
0
0
0
0
0
0
25
11A81
10
0
0
0
0
0
0
0
20
14-A-81
10
0
0
0
0
0
0
0
15
16-A-81
10
0
1
1
5
1
7
7
45
18-A-81
10
0
0
0
0
3
3
3
23
21-A-81
10
0
2
2
1
0
3
3
20
25-A-81
10
0
0
0
2
0
2
2
16
28-A-81
10
0
0
0
0
0
0
0
13
Ol-S-81
10
0
0
0
0
0
1
1
8
04-S-81
10
0
0
0
0
0
0
0
4
13-S-8I
10
0
0
0
0
0
0
0
60
28-A-82
10
0
0
0
0
0
0
0
53
Weight** Weight* Weight10 Weight11 Weight0 Weight* Weight*
1 2 3 A 5 6 7
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.038A62
0.000000
0.000000
0.000000
0.000000
0.022222
0.000000
0.100000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.038A62
0.000000
0.000000
0.000000
0.000000
0.022222
0.000000
0.100000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.1538A6
0.000000
0.000000
0.000000
0.000000
0.111111
0.000000
0.050000
0.125000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.022222
0.130A35
0.000000
0.000000
0.000000
0.125000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0. 192308
0.000000
0.000000
0.000000
0.000000
0.155556
0.130A35
0.150000
0.125000
0.000000
0.125000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.192308
0.000000
0.000000
0.000000
0.000000
0.155556
0.130A35
0.150000
0.125000
0.000000
0.125000
0.000000
0.000000
0.000000

Table C.8 (continued)
_ a
Date
(D-M-Y)
Hour**
Male0
Agg
Male4*
OAgg
Male*
All
Female1
Adult**
MFAh
Agg
MFA1
OAgg
Time
31-A-82
10
0
2
2
2
0
4
4
60
04-S-82
10
0
0
0
0
0
0
0
51
07-S-82
10
0
0
0
0
0
0
0
59
ll-S-82
10
0
0
0
0
0
0
0
59
14-S-82
10
0
0
0
0
0
0
0
60
18-S-82
10
0
1
1
2
0
3
3
60
21-S-82
10
0
0
0
0
0
0
0
58
25-S-82
10
0
1
1
0
0
1
1
53
02-0-82
10
0
0
0
1
0
l
1
40
05-0-82
10
0
1
1
0
0
1
1
31
09-0-82
10
0
0
0
0
0
0
0
7
04-A-81
11
0
0
0
0
0
0
0
30
07-A-81
11
0
0
0
0
0
0
0
35
11-A-8I
1 1
0
0
0
0
0
0
0
40
14-A-8I
11
0
0
0
0
0
0
0
45
I6-A-81
1 1
0
1
1
0
0
1
l
48
I8-A-8I
1 1
0
0
0
0
0
0
0
51
21-A-8I
1 1
0
0
0
0
0
0
0
56
25-A-81
1 1
0
0
0
0
0
0
0
60
Weight
3
Weight
4
Weight
5
Weight*4 Weight1
1 2
Weight** Weight4*
6 7
0.000000
0.033333
0.033333
0.033333
0.000000
0.066667
0.066667
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.016667
0.016667
0.033333
0.000000
0.050000
0.050000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.018868
0.018668
0.000000
0.000000
0.018868
0.018868
0.000000
0.000000
0.000000
0.025000
0.000000
0.025000
0.025000
0.000000
0.032258
0.032258
0.000000
0.000000
0.032258
0.032258
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.020833
0.020833
0.000000
0.000000
0.020833
0.020833
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
191

Table C.8 (continued)
Date3
(D-M-Y)
ii b
Hour
Male*
Agg
Male**
OAgg
Hale*
All
Female^
Adult**
MKAh
Agg
MFA1
OAgg
Time
28-A-81
1 1
0
0
0
0
0
0
0
60
0I-S-8I
1 1
0
0
0
0
0
0
0
60
04-S-81
1 1
0
0
0
0
1
1
1
60
08-S-8I
1 1
0
0
0
3
0
3
3
60
13-S-81
11
0
0
0
0
1
1
l
6
I5-S-8I
1 1
0
2
2
1
0
3
3
51
31-A-82
1 1
0
0
0
0
0
0
0
36
14-S-82
1 1
0
0
0
0
0
0
0
8
18-S-82
1 1
0
1
1
0
0
1
1
23
21-S-82
11
0
0
0
0
0
0
0
17
25-S-82
1 1
0
1
1
0
0
1
1
32
02-0-82
1 I
0
0
0
0
0
0
0
35
05-0-82
11
0
1
1
2
0
3
3
39
09-0-82
1 1
0
1
1
0
0
1
1
58
25-A-8I
12
0
0
0
0
0
0
0
2
28-A-8I
12
0
0
0
0
0
0
0
7
01-S-8I
12
0
0
0
0
0
0
0
U
04-S-81
12
0
0
0
0
0
0
0
19
Weight*1 Weight* Weight Weight Weight Weight*1 Weight**
1 2 3 A 5 6 7
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.039216
0.000000
0.000000
O.OA3A78
0.000000
0.031250
0.000000
0.0256A1
0.0172A1
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.039216
0.000000
0.000000
O.OA3A78
0.000000
0.031250
0.000000
0.0256A1
0.0172A1
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.050000
0.000000
0.019608
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.051282
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
o.oooooo
0.000000
0.000000
0.166667
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.050000
0. 166667
0.05882A
0.oooooo
0.000000
0.043A78
0.oooooo
0.031250
0.000000
0.076923
0.0172A1
0.000000
0.OOOOOO
0.OOOOOO
0.000000
0.000000
0.000000
0.000000
0.050000
0. 166667
0.05882A
0.000000
0.000000
0.0A3A78
0.000000
0.031250
0.000000
0.076923
0.0172A1
0.000000
0.000000
0.000000
0.000000

Table C.8 (continued)
Date3
(D-M-Y)
ii **
Hour
Ma leC
Agg
Male^
OAgg
Male*
All
Female^
Adult8
MFAh
*88
MFA1
OAgg
Tlmel
Weight**
1
Weight *
2
Weight
3
Weight"
4
Weight0
5
Weight*5
6
Weight**
7
08-S-81
12
0
0
0
0
0
0
0
25
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
15-S-81
12
0
0
0
0
0
0
0
38
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000
aD-M-Y Day, Month, Year; A August, S September, 0 October; 80 1980, 81 1981, 82 1982.
^Hour after sunset.
CMale Agg number of maleq feeding In aggregations. Total number of observed males was 159.
^Male OAgg number of males feeding that are not In aggregations. Total number of observed males was 108.
CMale All =* number of males feeding all males. Total number of observed males was 267.
^Female number of females feeding. Total number of observed females was 128.
^Adult number of adults feeding. Adults were not sexually Identified during the observations. Total number of observed adults was 53.
MFA Agg number of males (all males), females, and adults feeding. Total number of observations was 448.
MFA OAgg 3 number of observations of males (not In aggregations), females, and adults feeding. Total number of observations was 289.
^Tlme total observation minutes were 5865.0.
Ic
Weight 1 (Mnleagg/Mlnute)
193

Table C.8 (continued)
^Weight 2
"'Weight 3
nWeight U
Weight 5
^Weight 6
^Weight 7
(Male OAgg/Minute)
(Male All/Minute)
(Female/Minute)
(Adult/Minute)
(MFA Agg/Minute)
(MFA OAgg/Mlnute)
I
I
194

195 -
Table C.9. Sample mean and standard error of weighted
observations of feeding velvetbean caterpillar
males (in aggregations) grouped by post-sunset
hour, along with the percent normalized sample mean
and standard error. Observations were made from
1980-82 at the Green Acres Research Farm, Alachua
County, FL, in a 1 ha soybean field.
Hour After
Sunset
a
n
Sample Mean of
the Weighted
Observations
( SE)
Percent Normalized^
Sample Mean
( SE)
1
19
.0105
.0105
2.27
2.27
2
19
.0307
.0205
6.63
4.42
3
16
.0628
.0358
13.55
7.72
4
13
.0291
.0291
6.27
6.27
5
10
.2796
.1533
60.37
33.09
6
5
.0000
.0000
.00
.00
7
4
.0000
.0000
.00
.00
8
3
.0505
.0505
10.90
10.90
9
10
.0000
.0000
.00
.00
10
24
.0000
.0000
.00
.00
11
22
.0000
.0000
.00
.00
12
6
.0000
.0000
.00
.00
n = number of weighted observations per sample mean; n is not
the number of feeding males. See Table C.8 for a complete
listing of all observations and observational times.
i
Percent normalized sample mean = (sample mean of weighted
observations/0.463162)*100. Percent normalized standard error
= (standard error of sample mean/0.463162)*100.

196 -
Table C.10. Sample mean and standard error of weighted
observations of feeding velvetbean caterpillar
males (not in aggregations) grouped by post-sunset
hour, along with the percent normalized sample
mean and standard error. Observations were made
from 1980-82 at the Green Acres Research Farm,
Alachua County, FL, in a 1 ha soybean field.
Sample Mean of
b
the Weighted
Percent Normalized
Hour After
Observations
Sample Mean
Sunset
3.
n
( SE)
( SE)
1
19
.0204
+
.0107
9.48
+
4.98
2
19
.0185
+
.0085
8.61
+
3.96
3
16
.0237
+
.0107
11.03
+
4.97
4
13
.0369
+
.0112
17.14
+
5.22
5
10
.0165
+
.0101
7.66
+
4.67
6
5
.0302
+
.0247
14.05
+
11.48
7
4
.0000
+
.0000
.00
+
.00
8
3
.0373
+
.0188
17.34
+
8.76
9
10
.0142
+
.0077
6.61
+
3.56
10
24
.0093
+
.0045
4.43
+
2.09
11
22
.0081
+
.0031
3.76
+
1.43
12
6
.0000
+
.0000
.00
+
.00
n = number of weighted observations per sample mean; n is not
the number of feeding observations. See Table C.8 for a
complete listing of all observations and observational times.
^Percent normalized sample mean = (sample mean of weighted
observations/0.215046)* 100. Percent normalized standard error
= (standard error of sample mean/0.215046)*100.

197
Table C.ll. Sample mean and standard error of weighted
observations of feeding velvetbean caterpillar
males (all males) grouped by post-sunset hour,
along with the percent normalized sample mean and
standard error. Observations were made from
1980-82 at the Green Acres Research Farm, Alachua
County, FL, in a 1 ha soybean field.
Hour After
Sunset
a
n
Sample Mean of
the Weighted
Observations
( SE)
Percent Normalized^
Sample Mean
( SE)
1
19
.0309 .0142
4.56
2.09
2
19
.0492 .0234
7.26
3.45
3
16
.0865 .0346
12.75
5.10
4
13
.0659 .0281
9.72
4.15
5
10
.2961 .1591
43.65
23.46
6
5
.0302 .0247
4.45
3.64
7
4
.0000 .0000
.00
.00
8
3
.0878 .0639
12.95
9.42
9
10
.0142 .0077
2.10
1.13
10
24
.0093 .0045
1.37
.64
11
22
.0081 .0031
1.19
.45
12
6
.0000 .0000
.00
.00
3n = number
of weighted observations per
sample mean; n
is not
the number
of feeding observations. See
: Table C.8 for
a
complete listing of all observations and observational times.
i
Percent normalized sample mean = (sample mean of weighted
observations/0.678208)*100. Percent normalized standard error
= (standard error of weighted observations/0.678208)*100.

198
Table C.12. Sample mean and standard error of weighted
observations of feeding velvetbean caterpillar
females grouped by post-sunset hour, along with
the percent normalized sample mean and standard
error. Observations were made from 1980-82 at the
Green Acres Research Farm, Alachua County, FL, in
a 1 ha soybean field.
Sample Mean of
the Weighted
Hour After Observations
Sunset n3 ( SE)
Percent Normalized
Sample Mean
( SE)
b
1
19
.0026
+
.0014
.87
+
.47
2
19
.0242
+
.0106
7.99
+
3.47
3
16
.0253
+
.0139
8.32
+
4.59
4
13
.0248
+
.0098
8.15
+
3.22
5
10
.0480
+
.0149
15.77
+
4.92
6
5
.0329
+
.0172
10.84

5.66
7
4
.0000
+
.0000
.00
+
.00
8
3
.0974
+
.0441
32.04
+
14.50
9
10
.0274
+
.0153
9.03
+
5.04
10
24
.0157
+
.0070
5.18
+
2.32
11
22
.0055
+
.0032
1.81
+
1.07
12
6
.0000
+
.0000
.00
+
.00
n = number of weighted observations per sample mean; n is not
the number of feeding observations. See Table C.8 for a
complete listing of all observations and observational times.
I
Percent normalized sample mean = (sample mean of weighted
observations/0.303839)*100. Percent normalized standard error
= (standard error of weighted observations/0.303839)*100.

199
Table C.13. Sample mean and standard error of weighted
observations of feeding by unsexed velvetbean
caterpillar adults grouped by post-sunset hour,
along with the percent normalized sample mean and
standard error. Observations were made from
1980-82 at the Green Acres Research Farm, Alachua
County, FL, in a 1 ha soybean field.
Hour After
Sunset
b
n
Sample Mean of
the Weighted
Observations
( SE)
c
Percent Normalized
Sample Mean
( SE)
1
19
.0169
.0072
12.31
5.26
2
19
.0070
.0048
5.10
3.51
3
16
.0087
.0049
6.30
3.55
4
13
.0234
.0153
17.01
11.11
5
10
.0122
.0105
8.87
7.62
6
5
.0109
.0109
7.93
7.93
7
4
.0250
.0250
18.18
18.18
8
3
.0111
.0111
8.08
8.08
9
10
.0017
.0017
1.21
1.21
10
24
.0116
.0074
8.41
5.35
11
22
.0091
.0076
6.61
5.51
12
6
.0000
.0000
.00
.00
Unsexed adults flew out of sight before a positive sexual
identification could be made.
^n = number of weighted observations per sample mean; n is not
the number of feeding observations. See Table C.8 for
complete a listing of all observations and observational
times.
c
Percent normalized sample mean=(sample mean of weighted
observations/0.137529)*100. Percent normalized standard
error=(standard error of weighted observations/0.137529)*100.

200 -
Table C.14. Sample mean and standard error of weighted
observations of feeding by males (all), females,
and unsexed velvetbean caterpillar adults grouped
by post-sunset hour, along with the percent
normalized sample mean and standard error.
Observations were made from 1980-82 at the Green
Acres Research Farm, Alachua County, FL, in a 1 ha
soybean field.
Sample Mean of
the Weighted
Percent Normalized*2
Hour After
Observations
Sample Mean
Sunset
D
n
( SE)
( SE)
1
19
.0505
+
.0189
4.51
+
1.69
2
19
.0805
+
.0263
7.19
+
2.35
3
16
.1204
+
.0363
10.76
+
3.25
4
13
.1141

.0277
10.19
+
2.47
5
10
.3562

.1645
31.81
+
14.70
6
5
.0741

.0509
6.62
+
4.54
7
4
.0250

.0250
2.23
+
2.23
8
3
.1963
+
.1004
17.53
+
8.97
9
10
.0433
+
.0218
3.87
+
1.94
10
24
.0366
+
.0114
3.27
+
1.02
11
22
.0227
+
.0084
2.02
+
.75
12
6
.0000
+
.0000
.00
+
.00
Unsexed adults flew out of sight before a positive sexual
identification could be made.
n = number of weighted observations per sample mean; n is not
the number of feeding observations. See Table C.8 for a
complete listing of all observations and observational times.
Percent normalized sample mean = (sample mean of weighted
observations/1.11958)*100. Percent normalized standard error
= (standard error of weighted observations/1.11958)* 100.

201
Table C.15. Sample mean and standard error of weighted
observations of feeding by males (excluding
aggregations), females, and unsexed velvetbean
caterpillar adults grouped by post-sunset hour,
along with the percent normalized sample mean and
standard error. Observations were made from
1980-82 at the Green Acres Research Farm, Alachua
County, FL, in a 1 ha soybean field.
Hour After
Sunset
b
n
Sample Mean of
the Weighted
Observations
( SE)
c
Percent Normalized
Sample Mean
( SE)
1
19
.0399 .0171
6.08
2.61
2
19
.0498 1 .0166
7.59
2.54
3
16
.0577 .0229
8.79
3.49
4
13
.0850 .0183
12.95
2.79
5
10
0766A .0216
11.67
3.30
6
5
0741A .0509
11.28
7.75
7
4
.0250 .0250
3.81
3.81
8
3
.1458 .0515
22.21
7.84
9
10
.0433 .0218
6.60
3.31
10
24
.0366 .0114
5.58
1.74
11
22
.0227 .0084
3.45
1.28
12
6
.0000 .0000
.00
.00
Unsexed adults flew out of sight before a positive sexual
identification could be made.
^n = number of weighted observations per sample mean; n is not
the number of feeding observations. See Table C.8 for a
complete listing of all observations and observational times.
Percent normalized sample mean = (sample mean of weighted
observations/0.656414)*100. Percent normalized standard error
= (standard error of weighted observations/0.656414)*100.

APPENDIX D
ADULT DENSITY AND PHYSICAL VARIABLE DATA,
AND MATHEMATICAL DESCRIPTIONS OF PHYSICAL VARIABLES

Table D.l. Total number of females, males, and adults (male and
females) caught in a blacklight trap in 1980 at the
Green Acres Research Farm, Alachua County, FL. Trap
did not operate on dates 203, 207, 220, 225, 232, 236,
250, 251, and 254.
Total Number
Calendar Julian
Date Date Females Males Adults
4
186
0
0
0
5
187
0
0
0
6
188
0
0
0
7
189
0
0
0
8
190
1
0
1
9
191
0
0
0
10
192
0
0
0
11
193
0
0
0
12
194
2
0
2
13
195
0
0
0
14
196
0
0
0
15
197
0
0
0
16
198
0
1
1
17
199
0
1
1
18
200
0
1
1
19
201
0
0
0
20
202
0
0
0
21
203
-
-
-
22
204
1
1
2
23
205
2
0
2
24
206
0
3
3
25
207
-
-
-
26
208
0
2
2
27
209
0
1
1
28
210
0
2
2
29
211
1
2
3
30
212
1
3
4
203

204 -
Table D.l (continued)
Total Number
Calendar Julian
Date Date Females Males Adults
July 31
213
2
6
8
Aug. 1
214
0
3
3
2
215
4
1
5
3
216
4
2
6
4
217
9
2
11
5
218
16
29
45
6
219
11
37
48
7
220
-
-
-
8
221
30
30
60
9
222
13
12
25
10
223
20
19
39
11
224
7
44
51
12
225
-
-
-
13
226
38
54
92
14
227
26
14
40
15
228
13
24
37
16
229
34
55
89
17
230
24
21
45
18
231
21
41
62
19
232
-
-
-
20
233
36
51
87
21
234
43
96
139
22
235
24
48
72
23
236
-
-
-
24
237
49
66
115
25
238
56
73
129
26
239
30
90
120
27
240
89
177
266
28
241
55
39
94
29
242
97
129
226

- 205 -
Table D.l (continued)
Total Number
Calendar
Julian
Date
Date
Females
Males
Adults
Aug. 30
243
104
63
167
31
244
157
82
239
Sept. 1
245
179
96
275
2
246
102
36
138
3
247
111
76
187
4
248
51
29
80
5
249
62
17
79
6
250
-
-
-
7
251
-
-
-
8
252
30
11
41
9
253
24
14
38
10
254
-
-
-
11
255
11
10
21
12
256
28
19
47
13
257
22
23
45
14
258
56
25
81
15
259
52
37
89
16
260
42
30
72
17
261
28
9
37
18
262
47
36
83
19
263
25
30
55
20
264
44
59
103
21
265
34
30
64

Si b
Table D.2. Total, smoothed-total and weighted number of females, males, and adults (males and females)
caught in a blacklight trap in 1981 at the Green Acres Research Farm, Alachua County, FL. Trap
did not operate on date 174.
Calendar
Date
Julian
Date
Number of
Females
Number of
Males
Number of Total
Adults
Total
Smoothed
Weighted
Total
Smoothed
Weighted
Total
Smoothed
Weighted
June 21
172
0
0.00
0.00
0
0.00
0.00
0
0.00
0.00
22
173
0
0.00
0.00
0
0.00
0.00
0
0.00
0.00
23
174
-
-
-
-
-
-
-
-
-
24
175
0
0.00
0.00
0
0.00
0.00
0
0.00
0.00
25
176
0
0.00
0.00
1
0.00
0.00
1
0.00
0.00
26
177
0
0.00
0.00
0
0.00
0.00
0
0.00
0.00
27
178
0
0.00
0.00
0
0.00
0.00
0
0.00
0.00
28
179
0
0.00
0.00
0
0.00
0.00
0
0.00
0.00
29
180
0
0.00
0.00
0
0.00
0.00
0
0.00
0.00
30
181
0
0.00
0.00
0
0.00
0.00
0
0.00
0.00
July 1
182
0
0.00
0.00
0
0.00
0.00
0
0.00
0.00
2
183
0
0.00
0.00
0
0.00
0.00
0
0.00
0.00
3
184
0
0.00
0.00
0
0.00
0.00
0
0.00
0.00
4
185
0
0.00
0.00
0
0.00
0.00
0
0.00
0.00
5
186
0
0.00
0.00
0
0.00
0.00
0
0.00
0.00
6
187
0
0.00
0.00
0
0.00
0.00
0
0.00
0.00
206

Table D.2 (continued)
Number of Females
Number of Males
Number of Total
Adults
Calendar
Julian
Date
Date
Total Smoothed Weighted
Total Smoothed Weighted
Total Smoothed
Weighted
July 7
188
0
0.00
0.00
0
0.00
0.00
0
0.00
0.00
8
189
0
0.00
0.00
0
0.00
0.00
0
0.00
0.00
9
190
0
0.00
0.00
0
0.00
0.00
0
0.00
0.00
10
191
0
0.00
0.00
0
0.00
0.00
0
0.00
0.00
11
192
0
0.00
0.00
0
0.00
0.00
0
0.00
0.00
12
193
0
0.00
0.00
2
0.00
0.00
2
0.00
0.00
13
194
0
0.00
0.00
0
0.00
0.00
0
0.00
0.00
14
195
0
0.00
0.00
0
0.25
-1.00
0
0.25
-1.00
15
196
0
0.00
0.00
1
0.75
0.33
1
0.75
0.33
16
197
0
0.00
0.00
1
1.00
0.00
1
1.00
0.00
17
198
0
0.00
0.00
1
0.75
0.33
1
0.75
0.33
18
199
0
0.00
0.00
0
0.25
-1.00
0
0.25
-1.00
19
200
0
0.00
0.00
0
0.00
0.00
0
0.00
0.00
20
201
0
0.00
0.00
0
0.00
0.00
0
0.00
0.00
21
202
0
0.00
0.00
0
0.00
0.00
0
0.25
-1.00
22
203
1
0.00
0.00
0
0.50
-1.00
1
1.00
0.00
23
204
0
0.00
0.00
2
1.50
0.33
2
1.75
0.14
24
205
1
0.00
0.00
2
2.00
0.00
3
2.00
0.50
207

Table D.2 (continued)
Calendar
Date
Julian
Date
Number of
Females
Number of
Males
Number of Total
Adults
Total
Smoothed
Weighted
Total
Smoothed
Weighted
Total
Smoothed
Weighted
July 25
206
0
0.00
0.00
2
2.00
0.00
2
2.00
0.00
26
207
0
0.00
0.00
1
2.00
-0.50
1
2.00
-0.50
27
208
1
0.00
0.00
1
2.00
-0.50
2
2.00
0.00
28
209
1
0.00
0.00
3
2.00
0.50
4
2.00
1.00
29
210
0
0.00
0.00
2
2.00
0.00
2
2.00
0.00
30
211
0
0.00
0.00
3
2.00
0.50
3
2.00
0.50
31
212
0
0.00
0.00
1
1.81
-0.45
1
1.75
-0.43
Aug. 1
213
1
0.00
0.00
2
1.44
0.39
3
1.25
1.40
2
214
0
0.00
0.00
0
1.25
-1.00
0
1.00
-1.00
3
215
0
0.25
-1.00
2
2.19
-0.09
2
2.25
-0.11
4
216
1
0.75
0.33
5
4.94
0.01
6
5.75
0.04
5
217
1
1.25
-0.20
13
7.63
0.70
14
9.00
0.56
6
218
2
1.75
0.14
8
7.94
0.01
10
9.50
0.05
7
219
2
2.00
0.00
6
6.44
-0.07
8
8.25
-0.03
8
220
2
2.00
0.00
5
4.63
0.08
7
7.00
0.00
9
221
3
2.00
0.50
3
3.00
0.00
6
5.63
0.07
10
222
2
2.00
0.00
2
1.75
0.14
4
3.63
0.10
11
223
0
2.19
-1.00
0
1.50
-1.00
0
2.00
-1.00
208

Table D.2 (continued)
Number of Females
Number of Males
Number of Total
Adults
Calendar
Julian
Date
Date
Total Smoothed Weighted
Total Smoothed Weighted
Total Smoothed
Weighted
Aug. 12
224
0
2.56
-1.00
4
4.00
0.00
4
4.00
0.00
13
225
4
2.75
0.45
15
9.06
0.66
19
10.50
0.81
14
226
3
3.13
-0.04
11
13. 19
-0.17
14
16.25
-0.14
15
227
4
3.88
0.03
16
16.00
0.00
20
20.31
-0.02
16
228
1
5.00
-0.80
26
21.00
0.24
27
25.38
0.06
17
229
7
7.00
0.00
21
26.75
-0.22
28
29.31
-0.04
18
230
9
8.75
0.03
50
29.00
0.72
59
31.00
0.90
19
231
15
9.00
0.67
29
29.00
0.00
44
31.38
0.40
20
232
8
7.81
0.02
9
28.25
-0.68
17
31.13
-0.45
21
233
6
6.19
-0.03
24
26.75
-0.10
30
31.00
-0.03
22
234
5
5.50
-0.09
26
26.00
0.00
31
31.00
0.00
23
235
12
5.50
1.18
39
26.00
0.50
51
31.00
0.65
24
236
4
5.88
-0.32
23
24.69
-0.07
27
29.75
-0.09
25
237
10
6.63
0.51
42
22.06
0.90
52
27.25
0.91
26
238
3
7.00
-0.57
5
19.19
-0.74
8
25.00
-0.68
27
239
7
7.00
0.00
16
16.06
-0.00
23
23.00
0.00
28
240
14
7.25
0.93
42
14.25
1.95
56
22.00
1.55
29
241
22
7.50
1.93
59
13.75
3.29
81
22.00
2.68
209

Table D.2 (continued)
Calendar
Date
Julian
Date
Number of
Females
Number of
Males
Number of Total
Adults
Total
Smoothed
Weighted
Total
Smoothed
Weighted
Total
Smoothed
Weighted
Aug. 30
242
8
8.75
-0.09
9
13.50
-0.33
17
23.00
-0.26
31
243
3
11.50
-0.74
1
13.38
-0.93
4
27.75
-0.86
Sept. 1
244
14
14.25
-0.02
23
13.13
0.75
37
34.25
0.08
2
245
21
16.75
0.25
39
12.19
2.20
60
34.19
0.76
3
246
18
18.00
0.00
9
10.56
-0.15
27
28.56
-0.05
4
247
11
18.00
-0.39
3
9.75
-0.69
14
25.75
-0.46
5
248
18
18.00
0.00
14
9.75
0.44
32
25.75
0.24
6
249
21
18.00
0.17
13
9.75
0.33
34
25.00
0.36
7
250
6
18.00
-0.67
3
10.50
-0.71
9
24.75
-0.64
8
251
10
18.19
-0.45
16
16.00
0.00
26
30.50
-0.15
9
252
16
18.56
-0.14
32
32.25
-0.01
48
48.00
0.00
10
253
20
18.75
0.07
68
53.19
0.28
88
70.25
0.25
11
254
18
19.06
-0.06
62
74.00
-0.16
80
90.44
-0.11
12
255
37
21.94
0.69
195
95.31
1.05
232
113.31
1.05
13
256
14
26.75
-0.48
102
105.75
-0.04
116
130.25
-0.11
14
257
30
29.00
0.03
175
106.25
0.65
205
134.50
0.52
15
258
29
29.00
0.00
104
104.00
0.00
133
133.00
0.00
16
259
23
28.25
-0.19
83
95.38
-0.13
106
123.94
-0.14
210

Table D.2 (continued)
Calendar
Date
Julian
Date
Number of
Females
Number of
Males
Number of Total
Adults
Total
Smoothed
Weighted
Total
Smoothed
Weighted
Total
Smoothed
Weighted
Sept. 17
260
32
26.75
0.20
95
80.63
0. 18
127
106.81
0.19
18
261
26
26.00
0.00
66
66.00
0.00
92
92.00
0.00
19
262
6
26.25
-0.77
13
53.00
-0.75
19
82.25
-0.77
20
263
1
26.75
-0.96
9
41.13
-0.78
10
75.00
-0.87
21
264
27
27.00
0.00
58
35.63
0.63
85
72.25
0.18
22
265
66
29.00
1.28
93
35.25
1.64
159
75.69
1.10
23
266
27
33.00
-0.18
37
37.94
-0.02
64
82.56
-0.22
24
267
35
35.00
0.00
39
43.31
-0.10
74
86.00
-0.14
25
268
46
35.00
0.31
46
46.00
0.00
92
85.50
0.08
26
269
48
36.00
0.33
114
46.63
1.45
162
84.50
0.92
27
270
33
38.00
-0.13
50
47.88
0.04
83
83.00
0.00
28
271
32
39.00
-0.18
47
47.00
0.00
79
78.69
0.00
29
272
42
39.00
0.08
29
41.88
-0.31
71
72.81
-0.02
30
273
39
39.00
0.00
31
35.13
-0.12
70
70.00
0.00
Oct. 1
274
29
38.75
-0.25
36
31.50
0.14
65
69.56
-0.07
2
275
41
38.25
0.07
42
32.50
0.29
83
69.19
0.20
3
276
38
37.19
0.02
31
35.50
-0.13
69
69.00
0.00
4
277
35
35.25
-0.01
26
37.50
-0.31
61
69.50
-0.12
211

Table D.2 (continued)
Number of Females
Number of Males
Number of Total
Adults
Calendar
Julian
Date
Date
Total Smoothed Weighted
Total Smoothed Weighted
Total Smoothed
Weighted
Oct. 5
278
34
33.81
0.01
41
38.00
0.08
75
70.50
0.06
6
279
33
33.50
-0.01
38
38.00
0.00
71
71.00
0.00
7
280
23
33.25
-0.31
18
37.50
-0.52
41
71.00
-0.42
8
281
36
32.75
0.10
49
36.50
0.34
85
71.00
0.20
9
282
35
29.38
0.19
36
33.75
0.07
71
65.00
0.09
10
283
20
20.38
-0.02
27
29.25
-0.08
47
53.00
-0.11
11
284
6
11.50
-0.48
9
23.25
-0.61
15
40.25
-0.63
12
285
9
8.25
0.09
47
15.75
1.98
56
26.75
1.09
13
286
8
8.00
0.00
12
12.00
0.00
20
20.00
0.00
14
287
1
8.00
-0.88
10
12.00
-0.17
11
20.00
-0.45
15
288
11
8.00
0.38
17
12.00
0.42
28
20.00
0.40
£
Total numbers were smoothed with a nonlinear data-smoothlng algorithm (3RSSH, twice) based on running
medians (see Velleman 1980, Ryan et al. 1982).
Weighted Total # = (Total # Smoothed #)/(Smoothed //) .
212

Si b
Table D.3. Total, smoothed-total and weighted number of females, males, and adults (males and females)
caught in a blacklight trap in 1982 at the Green Acres Research Farm, Alachua County, FL. Trap
did not operate on date 235.
Calendar
Date
Julian
Date
Number of
Females
Number of
Males
Number of Total
Adults
Total
Smoothed
Weighted
Total
Smoothed
Weighted
Total
Smoothed
Weighted
June 21
172
0
0.00
0.00
0
0.00
0.00
0
0.00
0.00
22
173
0
0.00
0.00
0
0.00
0.00
0
0.00
0.00
23
174
0
0.00
0.00
0
0.00
0.00
0
0.00
0.00
24
175
0
0.00
0.00
0
0.00
0.00
0
0.00
0.00
25
176
0
0.00
0.00
0
0.00
0.00
0
0.00
0.00
26
177
0
0.00
0.00
0
0.00
0.00
0
0.00
0.00
27
178
0
0.00
0.00
0
0.00
0.00
0
0.00
0.00
28
179
0
0.00
0.00
0
0.00
0.00
0
0.00
0.00
29
180
0
0.00
0.00
0
0.00
0.00
0
0.00
0.00
30
181
0
0.00
0.00
0
0.00
0.00
0
0.00
0.00
July 1
182
0
0.00
0.00
0
0.00
0.00
0
0.00
0.00
2
183
0
0.00
0.00
0
0.00
0.00
0
0.00
0.00
3
184
0
0.00
0.00
0
0.00
0.00
0
0.00
0.00
4
185
0
0.00
0.00
0
0.00
0.00
0
0.00
0.00
5
186
0
0.00
0.00
0
0.00
0.00
0
0.00
0.00
6
187
0
0.00
0.00
0
0.00
0.00
0
0.00
0.00
213

Table D.3 (continued)
Number of Females
Number of Males
Number of Total
Adults
Calendar
Julian
Date
Date
Total Smoothed Weighted
Total Smoothed Weighted
Total Smoothed
Weighted
July 7
188
0
0.09
O
O
I
0
0.01
-1.00
0
0.07
i

o
o
8
189
0
0.34
-1.00
0
0.05
-1.00
0
0.34
-1.00
9
190
1
0.59
0.70
0
0.30
-1.00
1
0.84
0.20
10
191
1
0.67
0.49
1
0.70
0.44
2
1.38
0.45
11
192
0
0.59
-1.00
1
0.97
0.03
1
1.69
-0.41
12
193
2
0.34
4.89
1
1.08
-0.07
3
1.69
0.77
13
194
0
0.09
-1.00
2
1.17
0.71
2
1.57
0.27
14
195
0
0.00
0.00
1
1.31
-0.24
1
1.52
-0.34
15
196
0
0.00
0.00
1
1.41
-0.29
1
1.51
-0.34
16
197
0
0.00
0.00
2
1.42
0.41
2
1.43
0.40
17
198
1
0.08
11.20
2
1.26
0.59
3
1.24
1.42
18
199
0
0.41
-1.00
0
0.87
-1.00
0
1.12
-1.00
19
200
0
0.95
-1.00
0
0.50
-1.00
0
1.22
-1.00
20
201
4
1.38
1.90
1
0.30
2.37
5
1.58
2.16
21
202
2
1.50
0.33
0
0.21
-1.00
2
1.93
0.03
22
203
1
1.45
-0.31
2
0.32
5.24
3
2.06
0.45
23
204
2
1.38
0.45
0
0.75
-1.00
2
2.09
-0.04
24
205
1
1.32
-0.24
1
1.44
-0.31
2
2.30
-0.13
214

Table D.3 (continued)
Calendar
Date
Julian
Date
Number of
Females
Number of
Males
Number of Total
Adults
Total
Smoothed
Weighted
Total
Smoothed
Weighted
Total
Smoothed
Weighted
July 25
206
0
1.50
-1.00
3
2.29
0.31
3
3.21
-0.06
26
207
2
2.44
-0.18
3
3.28
-0.08
5
5.38
-0.07
27
208
4
3.76
0.06
4
4.14
-0.03
8
8.00
0.00
28
209
6
4.33
0.39
5
4.81
0.04
11
9.42
0.17
29
210
5
3.85
0.30
7
5.50
0.27
12
9.52
0.26
30
211
2
2.90
-0.31
2
6.08
-0.67
4
9.09
-0.56
31
212
0
2.42
-1.00
9
6.36
0.42
9
8.71
0.03
Aug. 1
213
2
2.56
-0.22
5
6.50
-0.23
7
8.66
-0.19
2
214
6
2.83
1.12
8
6.66
0.20
14
8.78
0.59
3
215
4
3.22
0.24
5
6.99
-0.28
9
9.22
-0.02
4
216
1
3.36
-0.70
9
7.20
0.25
10
9.55
0.05
5
217
10
3.02
2.32
33
7.43
3.44
43
9.78
3.40
6
218
2
3.41
-0.41
5
8.60
-0.42
7
11.86
-0.41
7
219
3
5.70
-0.47
5
13.62
-0.63
8
19.67
-0.59
8
220
10
9.73
0.03
18
25.89
-0.30
28
36.29
-0.23
9
221
16
13.28
0.20
57
38.74
0.47
73
52.67
0.39
10
222
21
14.47
0.45
57
43.41
0.31
78
58.42
0.34
11
223
15
13.93
0.08
39
37.82
0.03
54
52.28
0.03
215

Table D.3 (continued)
Number of Females
Number of Males
Number of Total
Adults
Calendar
Julian
Date
Date
Total Smoothed Weighted
Total Smoothed Weighted
Total Smoothed
Weighted
Aug. 12
224
10
12.84
-0.22
18
26.65
-0.32
28
40.00
-0.30
13
225
11
12.55
-0.12
18
21.06
-0.15
29
33.86
-0.14
14
226
15
14.85
0.01
23
25.11
-0.08
38
39.79
-0.05
15
227
20
20.99
-0.05
34
39.27
-0.13
54
59.90
-0.10
16
228
31
30.26
0.02
62
55.44
0.12
93
85.28
0.09
17
229
51
38.35
0.33
70
61.50
0.14
121
99.46
0.21
18
230
37
41.25
-0.10
63
60.85
0.04
100
102.42
-0.02
19
231
48
39.50
0.22
72
51.98
0.39
120
91.97
0.30
20
232
37
33.88
0.09
22
33.57
-0.34
59
66.49
-0.11
21
233
24
27.33
-0.12
11
20.75
-0.47
35
46.34
-0.24
22
234
19
24.09
-0.21
21
18.27
0.15
40
41.29
-0.03
23
235
-
-
-
-
-
-
-
-
-
24
236
28
23.52
0.19
22
18.69
0.18
50
42.88
0.17
25
237
26
25.34
0.03
16
19.31
-0.17
42
45.56
-0.08
26
238
19
31.93
-0.40
18
22.56
-0.20
37
55.84
-0.34
27
239
75
45.11
0.66
86
33.36
1.58
161
78.48
1.05
28
240
43
60.29
-0.29
38
51.72
-0.27
81
109.05
-0.26
29
241
64
71.98
-0.11
34
70.21
-0.52
98
137.84
-0.29
216

Table D.3 (continued)
Number of Females
Number of Males
Number of Total
Adults
Calendar
Julian
Date
Date
Total Smoothed Weighted
Total Smoothed Weighted
Total Smoothed
Weighted
Aug. 30
242
106
79.25
0.34
121
82.76
0.46
227
157.30
0.44
31
243
75
81.64
-0.08
88
86.57
0.02
163
163.42
0.00
Sept. 1
244
97
80.69
0.20
97
84.07
0.15
194
161.28
0.20
2
245
75
77.10
-0.03
75
77.73
-0.04
150
153.59
-0.02
3
246
75
69.58
0.08
68
69.65
-0.02
143
139.95
0.02
4
247
50
61.20
-0.18
59
64.05
-0.08
109
125.47
-0.13
5
248
53
56.57
-0.06
63
60.91
0.03
116
115.58
0.00
6
249
62
55.58
0.12
63
58.59
0.08
125
112.38
0.11
7
250
41
56.21
-0.27
53
57.84
-0.08
94
114.18
-0.18
8
251
72
59.86
0.20
35
57.63
-0.39
107
118.57
-0.10
9
252
52
65.23
-0.20
84
55.13
0.52
136
121.94
0.12
10
253
141
67.59
1.09
62
49.71
0.25
203
120.72
0.68
11
254
81
64.89
0.25
37
41.19
-0.10
118
110.27
0.07
12
255
43
57.60
-0.25
28
32.55
-0.14
71
92.67
-0.23
13
256
33
50.52
-0.35
27
27.78
-0.03
60
78.53
-0.24
14
257
57
46.99
0.21
50
26.28
0.90
107
71.16
0.50
15
258
51
44.82
0.14
24
26.39
-0.09
75
67.72
0.11
16
259
39
41.67
-0.06
27
26.52
0.02
66
64.53
0.02
217

Table D.3 (continued)
Calendar
Date
Julian
Date
Number of
Females
Number of
Males
Number of Total
Adults
Total
Smoothed
Weighted
Total
Smoothed
Weighted
Total
Smoothed
Weighted
Sept. 17
260
31
37.29
-0.17
28
26.08
0.07
59
60.47
-0.02
18
261
39
32.69
0.19
14
25.45
-0.45
53
56.59
-0.06
19
262
29
29.00
0.00
35
24.89
0.41
64
53.09
0.21
20
263
24
26.82
-0.11
19
24.19
-0.21
43
50.58
-0.15
21
264
27
25.26
0.07
23
23.36
-0.02
50
48.33
0.03
22
265
28
23.87
0.17
37
23.14
0.60
65
46.22
0.41
23
266
15
23.46
-0.36
5
23.25
-0.78
20
45.53
-0.56
24
267
13
23.71
-0.45
9
23.25
-0.61
22
45.78
-0.52
25
268
38
23.84
0.59
38
23.25
0.63
76
45.91
0.66
26
269
46
24.06
0.91
42
23.36
0.80
88
46.98
0.87
27
270
3
24.50
-0.88
7
23.78
-0.71
10
49.13
-0.80
28
271
10
27.84
-0.64
12
25.14
-0.52
22
54.42
-0.60
29
272
35
34.38
0.02
23
28.38
-0.19
58
64.03
-0.09
30
273
57
38.09
0.50
82
31.84
1.58
139
70.60
0.97
Oct. 1
274
v 60
37.88
0.58
53
33.14
0.60
113
71.72
0.58
2
275
23
34.56
-0.33
24
30.04
-0.20
47
64.98
-0.28
3
276
23
29.06
-0.21
20
23.27
-0.14
43
51.33
-0.16
4
277
26
25.82
0.01
15
18.11
-0.17
41
42.93
-0.04
218

Table D.3 (continued)
Number of Females
Number of Males
Number of Total
Adults
Calendar
Julian
Date
Date
Total Smoothed Weighted
Total Smoothed Weighted
Total Smoothed
Weighted
Oct. 5
278
43
24.42
0.76
36
15.40
1.33
79
39.29
1.01
6
279
24
20.93
0.15
14
13.86
0.01
38
34.31
0.11
7
280
13
16.29
-0.20
14
13.11
0.07
27
29.69
-0.09
8
281
12
14.22
-0.16
15
12.08
0.24
27
27.50
-0.02
9
282
14
14.24
-0.02
5
11.22
-0.55
19
27.41
-0.31
10
283
20
15.22
0.31
9
11.16
-0.19
29
28.22
0.03
11
284
16
17.14
-0.07
14
11.67
0.20
30
29.34
0.02
12
285
17
18.66
-0.09
12
12.09
-0.01
29
30.07
-0.04
13
286
54
19.44
1.78
22
11.70
0.88
76
30.25
1.51
14
287
18
19.34
-0.07
11
9.38
0.17
29
28.74
0.01
15
288
26
15.43
0.69
5
6.09
-0.18
31
22.35
0.39
16
289
4
8.66
-0.54
1
4.52
-0.78
5
14.10
-0.65
17
290
3
5.38
-0.44
3
4.65
-0.35
6
10.73
-0.44
18
291
7
5.76
0.21
9
5.16
0.74
16
11.75
0.36
19
292
2
8.01
-0.75
7
5.52
0.27
9
14.77
-0.39
20
293
15
11.28
0.33
5
5.73
-0.13
20
17.82
0.12
21
294
18
12.88
0.40
4
5.83
-0.31
22
18.94
0.16
22
295
13
13.00
0.00
6
5.83
0.03
19
19.00
0.00
219

Table D.3 (continued)
Total numbers were smoothed with a nonlinear data-smoothing algorithm (3RSSH, twice) based on running
medians (see Velleman 1980, Ryan et al. 1982).
^Weighted Total // = (Total // Smoothed #)/ (Smoothed #).

Table D.4. Total females, males, and adults (females and males) caught in an adult trap-cage during
1982 at the Green Acres Research Farm, Alachua County, FL (n = 6, N = 416.59).
Total Number
Julian Sample
Date Number Females Males Adults
Total Number
Julian Sample
Date Number Females Males Adults
196 1
2
3
4
5
6
0 0 0
0 0 0
0 0 0
0 0 0
0 0 0
0 0 0
217
1
2
3
4
5
6
0
1
2
2
0
1
0
0
0
0
0
0
0
1
2
2
0
1
i
203 1
2
3
4
5
6
0 0 0
0 0 0
0 0 0
0 0 0
0 0 0
0 0 0
224 1
2
3
4
5
6
0
1
1
2
1
0
0
0
0
0
0
0
0
1
1
2
1
0
i
210 1
2
3
4
5
6
0 0 0
0 0 0
0 0 0
0 0 0
0 0 0
0 0 0
231 1
2
3
4
5
6
1 1 2
0 0 0
0 3 3
1 0 1
3 1 4
1 0 1
221

Table D.4 (continued)
Julian
Date
238
245
252
Total Number
Sample
Number Females Males Adults
Total Number
Julian Sample
Date Number Females Males Adults
259 1
2
3
4
5
6
0 0 0
4 1 5
4 0 4
1 2 3
1 1 2
0 3 3
266 1
2
3
4
5
6
0
0
2
2
7
0
1
1
0
3
2
0
1
1
2
5
9
0
i
273 1
2
3
4
5
6
2 0 2
0 0 0
0 5 5
0 0 0
0 0 0
1 0 1
222

Table D.4 (continued)
Total Number
Julian Sample
Date Number Females Males Adults
280 1 0
2 0
3 0
4 0
5 4
6 1
0
0
0
0
1
0
0
0
0
0
5
1
Total Number
Julian Sample
Date Number Females Males Adults
287 1 0
2 0
3 0
4 2
5 1
6 3
0
0
0
1
0
0
0
0
0
3
1
3
i
i
223

196
203
210
217
224
231
238
245
252
259
266
273
280
287
224 -
Mean number (SE) of females, males, and total adults
per 21.16 m2 caught in an adult trap-cage during 1982
at the Green Acres Research Farm, Alachua County, FL
(n = 6, N = 416.59).
Mean Number (SE)
Female Male Adult
.00
+
.00
.00
+
.00
.00
.00
.00
+
.00
.00
+
.00
.00
.00
.00
+
.00
.00
+
.00
.00
.00
1.00
+
.37
.00

.00
1.00
.37
.83
+
.31
.00

.00
.83
.31
1.00
+
.45
.83
+
.48
1.83
.60
4.33
+
.67
3.17
+
.75
7.50
.81
6.17
+
.87
6.33
+
1.20
12.50
1.96
5.50
+
1.57
5.17
+
.65
10.67
2.14
1.67
+
.76
1.17
+
.48
2.83
.70
1.83
+
1.11
1.17
+
.48
3.00
1.39
.50
+
.34
.83
+
.83
1.33
.80
.83
+
.65
.17
+
.17
1.00
.82
1.00
+
.52
.17
+
.17
1.17
.60

- 225
Table D.6. Mathematical description of selected physical variables (see
Table 4.1). Variable values were regressed against
blacklight trap catch data. Variable values are listed in
Tables D.7 and D.8.
Flight Temperature (C)
Flight Temp. = (ATC)*(11.9C)
where AT = mean ambient temperature C, based on data
recorded at 1 hr intervals during scotophase,
11.9C = flight threshold temperature (see Chapter III).
Vapor Pressure Deficit (mm Hg)
21.006534( 5317.030)
Vapor Pressure Deficit = (l-RH)e K
where RH = % Relative Humidity,
e = 2.71828,
K = degree Kelvin.
Equation modified from Merva (1975).
Moonlight Illuminence
Moonlight Illuminence = I*T*C,
where I = proportional moonlight intensity (see Gardiner
1968),
T = proportional time that moon was above the horizon
during the night,
C = proportional opaque cloud coverage (0 = totally
overcast, 1 = totally clear sky)(see NOAA 1981,
1982).
Wind Speed (m/s)
Wind Speed = mean wind speed, based on data recorded at 15 min
intervals during scotophase.

226 -
Table D.6 (continued)
Wind Direction
Wind Direction = values that vary from 1 to 360,
where 90 = due east,
180 = due south,
270 = due west,
360 = due north.
Rainfall
Rainfall = R*T,
where R = proportional amount of rainfall, based on
centimeters per rainfall per night,
T = proportional length of rainfall duration, based
on hours.
Barometric Pressure (MB)
Barometric Pressure = mean barometric pressure, based on data
recorded at 1 h intervals during scotophase.

Table D.7. Values of physical variables regressed against blacklight trap catch data (1981). Mathematical
descriptions of physical variables are listed in Table D.6.
Vapor
Press. Wind
Calendar
Date
Julian
Date
Flight
Temp. (C)
Deficit
(mm Hg)
Moonlight
Intensity
Speed
(m/s)
Wind
Direction
Rainfall
Barometric
Press. (MB)
Aug. 4
216
9.11
.407
.0000
.869
161.3
.0803
1020.93
5
217
10.42
.944
.0198
.081
148.2
.0000
1019.95
6
218
11.89
1.576
.0347
.092
124.0
.0000
1015.94
7
219
13.00
1.992
.0482
.254
155.8
.0000
1013.23
8
220
13.20
1.965
.0891
.224
138.1
.0000
1015.98
9
221
13.50
2.705
.1028
.386
166.7
.0000
1020.29
10
222
11.84
2.067
.1901
.203
154.6
.0000
1020.78
11
223
10.17
.595
.0502
.297
128.3
.0031
1018.28
12
224
10.37
1.477
.1967
.253
149.2
.0000
1017.84
13 .
225
11.08
1.066
.2583
.571
129.2
.0000
1018.89
14
226
10.93
2.272
.8455
.505
120.1
.0000
1017.45
15
227
11.33
2.837
.9200
.647
151.8
.0000
1014.16
16
228
12.24
3.700
.7953
.773
135.6
.0000
1010.87
17
229
12.65
2.496
.4797
1.868
123.5
.0000
1010.36
18
230
11.89
2.539
.0236
2.137
93.0
.0000
1009.13
19
231
12.54
2.388
.0388
.494
156.1
.0000
1011.93
227

Table D.7 (continued)
Vapor
Press.
Calendar
Date
Julian
Date
Flight
Temp. (C)
Deficit
(mm Hg)
Aug. 20
232
10.93
.813
21
233
10.93
.858
22
234
11.58
1.396
23
235
12.04
2.473
24
236
10.57
1.671
25
237
7.95
1.248
26
238
10.22
.980
27
239
10.78
.675
28
240
10.68
.866
29
241
10.37
.520
30
242
10.57
.426
31
243
10.52
1.251
Sept. 1
244
10.83
1.654
2
245
9.97
2.021
3
246
10.73
1.600
4
247
11.74
2.092
5
248
11.99
1.414
Moonlight
Intensity
.0125
.0228
.0408
.0154
.0216
.0057
.0000
.0000
.0000
.0000
.0000
.0026
.0021
.0063
.0079
.0167
.0000
Wind
Speed Wind Barometric
(m/s) Direction Rainfall Press. (MB)
.701
163.6
.0000
1013.97
.710
139.4
.0000
1014.85
1.693
167.4
.0003
1017.34
.950
95.8
.0000
1017.16
.801
116.1
.0000
1017.66
.597
107.4
.0000
1016.46
1.307
135.6
.0000
1015.57
1.556
169.5
.0467
1016.89
1.161
165.1
.0000
1018.85
.300
141.4
.0057
1016.48
.137
139.9
.0000
1014.74
.541
117.3
.0000
1013.60
.328
129.5
.0000
1012.95
.207
126.5
.0000
1014.32
. 101
118.5
.0000
1014.65
.259
117.9
.0000
1014.71
.651
130.7
.0000
1015.35
228

Table D.7 (continued)
Calendar Julian
Date Date
Vapor
Press.
Flight Deficit Moonlight
Temp. (C) (mm Hg) Intensity
6
249
10.73
.633
.0429
7
250
9.31
.710
.0850
8
251
10.73
1.231
.0787
9
252
10.63
1.338
.1814
10
253
9.26
.629
.1092
11
254
10.27
2.141
.3948
12
255
8.71
1.201
.4914
13
256
9.82
2.117
.9500
14
257
.83
1.648
.9700
15
258
.0
.420
.8372
16
259
3.25
.699
.1449
17
260
-
-
.1446
18
261
-
-
.1086
19
262
-
-
.1324
20
263
-
-
.0210
21
264
8.70
1.251
.0143
22
265
7.27
1.255
.0231
Wind
Speed Wind Barometric
(m/s) Direction Rainfall Press. (MB)
207
115.5
.0000
1016.45
274
162.1
.0000
1014.99
064
165.8
.0000
1012.16
194
152.9
.0000
1012.35
-
-
.0000
1016.08
731
143.9
.0000
1018.46
391
121.7
.0000
1017.31
402
143.9
.0000
1015.75
137
143.2
.0000
1015.81
271
154.3
.0343
1015.65
710
169.5
.0000
1016.54
937
118.0
.0000
1017.63
697
81.9
.0000
1020.00
073
96.5
.0000
1018.67
322
115.4
.0000
1017.23
516
135.4
.0038
1016.00
052
124.7
.0000
1016.75
229

Table D.7 (continued)
Calendar
Date
Vapor
Press.
Julian Flight Deficit Moonlight
Date Temp. (C) (mm Hg) Intensity
Sept. 23
266
7.73
1.249
.0093
24
267
5.41
2.469
.0051
25
268
8.05
2.701
.0000
26
269
6.11
.846
.0008
27
270
7.17
1.049
.0000
28
271
6.11
1.425
.0000
29
272
8.56
1.768
.0000
30
273
5.32
1.440
.0025
Oct. 1
274
6.29
1.973
.0033
2
275
6.62
4.281
.0066
3
276
4.16
1.439
.0126
4
277
8.93
2.777
.0243
5
278
6.16
2.299
.0392
6
279
5.74
1.395
.0633
7
280
10.37
3.233
.0319
8
281
8.33
2.452
.0126
9
282
9.86
1.314
.0664
Wind
Speed Wind Barometric
(m/s) Direction Rainfall Press. (MB)
.450
125.9
.0000
1019.55
1.451
140.4
.0000
1022.64
1.919
132.6
.0000
1020.88
-
-
.0000
1020.39
.374
105.9
.0000
1019.23
.366
107.7
.0000
1018.56
.864
139.8
.0000
1019.56
.324
129.0
.0000
1019.98
.229
118.1
.0000
1016.20
1.100
96.7
.0000
1012.88
1.561
107.7
.0000
1017.62
.889
161.6
.0000
1020.01
.644
142.1
.0000
1020.36
.144
140.0
.0000
1015.79
.259
128.1
.0000
1011.93
1.753
153.2
.0000
1015.11
.644
131.5
.0000
1016.87
230

Table D.7 (continued)
Vapor
Calendar
Date
Julian
Date
Flight
Temp. (C)
Press.
Deficit
(mm Hg)
Moonlight
Intensity
Wind
Speed
(m/s)
Wind
Direction
Rainfall
Barometric
Press. (MB)
Oct. 10
283
9.49
1.008
.0927
.592
120.0
.0000
1016.63
11
284
6.61
1.452
.1334
2.385
104.0
.0000
1018.64
12
285
3.27
1.928
.9306
2.201
107.7
.0000
1020.12
13
286
3.44
1.649
.8004
2.553
102.9
.0000
1020.58
14
287
3.10
.794
.7866
2.551
104.6
.0000
1021.38
15
288
.00
.741
.5525
.116
93.7
.0000
1018.32
231

- 232 -
Table D.8
. Values of physical variables regressed
trap catch data (1982). Mathematical
physical variables are listed in Table
against blacklight
descriptions of
D.6.
Calendar
Date
Julian
Date
Flight
Temp. (C)
Vapor
Press.
Deficit
(mm Hg)
Moonlight
Intensity
Rainfall
Barometric
Press. (MB)
July 27
208
10.98
.124
.0066
.0000
1016.95
28
209
10.73
.399
.0440
.0000
1016.69
29
210
10.37
.978
.0707
.0000
1019.76
30
211
10.73
.967
.1819
.0000
1021.74
31
212
12.04
1.197
.2598
.0000
1018.99
Aug. 1
213
11.89
2.099
.4063
.0000
1017.22
2
214
12.34
.433
.4914
.0000
1014.62
3
215
10.68
.574
.6650
.0000
1014.38
4
216
10.63
.882
.6900
.0000
1016.57
5
217
9.31
.109
.6570
.0000
1017.96
6
218
8.40
.000
.5817
.0000
1018.80
7
219
11.28
.363
.3720
.0000
1019.13
8
220
11.64
1.675
.0439
.0000
1018.94
9
221
11.08
.524
.0077
.0000
1020.16
10
222
8.91
.752
.1387
.0000
1021.05
11
223
10.47
.966
.0972
.0000
1019.39
12
224
11.53
.874
.0693
.0000
1017.11
13
225
11.79
.235
.0292
.0000
1015.84
14
226
10.17
.104
.0076
.0000
1015.25
15
227
11.94
1.910
.0079
.0000
1016.27
16
228
11.48
.338
.0029
.0000
1016.20
17
229
10.32
.403
.0003
.0000
1015.24
18
230
9.82
.000
.0000
.0000
1015.30
19
231
10.42
.000
.0000
.0000
1019.74
20
232
10.78
.425
.0000
.0000
1020.18
21
233
10.92
.000
.0005
.0000
1017.25
22
234
11.39
.059
.0036
.0000
1017.71

- 233 -
Table D.8 (continued)
Vapor
Press.
Calendar
Date
Julian
Date
Flight
Temp. (C)
Deficit
(mm Hg)
Aug. 23
235
11.29
.122
24
236
11.84
.266
25
237
11.48
.000
26
238
11.79
.022
27
239
10.68
.000
28
240
10.42
1.262
29
241
11.18
1.341
30
242
9.21
.559
31
243
9.56
.677
Sept. 1
244
8.76
.954
2
245
12.14
1.204
3
246
12.75
1.381
4
247
11.08
1.030
5
248
10.27
.000
6
249
9.67
.219
7
250
9.92
.000
8
251
11.08
.000
9
252
11.64
.000
10
253
10.07
.000
11
254
11.43
.000
12
255
10.27
.000
13
256
9.87
.631
14
257
8.66
.058
15
258
10.07
.000
16
259
11.18
.249
17
260
9.31
.326
18
261
10.07
.491
19
262
9.56
.000
20
263
10.51
.228
Moonlight Barometric
Intensity
Rainfall
Press. (MB)
.0054
.0000
1018.63
.0207
.0000
1017.89
.0139
.0000
1015.41
.0000
.0000
1015.01
.0297
.0000
1015.67
.0530
.0061
1016.65
.1737
.0000
1020.18
.2952
.0000
1021.21
.4234
.0000
1020.16
.6237
.0000
1017.54
.6175
.0000
1015.25
.7100
.0000
1014.61
.6916
.0000
1015.76
.3135
.0000
1013.71
.3109
.0000
1018.80
.1276
.0025
1017.62
.0818
.0000
1016.82
.0309
.0000
1016.02
.0447
.0000
1015.74
.0389
.0000
1017.13
.0140
.0000
1019.45
.0062
.0000
1013.92
.0036
.0000
1016.52
.0009
.0000
1014.05
.0000
.0000
1013.59
.0000
.0000
1014.29
.0000
.0043
1013.26
.0001
.0000
1013.44
.0016
.0000
1014.13

- 234 -
Table D.8 (continued)
Vapor
Press.
Calendar Julian Flight Deficit
Date Date Temp. (C) (mm Hg)
21
264
9.95
.208
22
265
4.58
.673
23
266
4.91
.233
24
267
7.27
.578
25
268
4.67
.218
26
269
3.29
.343
27
270
5.60
.512
28
271
7.31
.918
29
272
9.91
.680
30
273
10.04
.035
1
274
7.68
.577
2
275
7.41
.284
3
276
9.58
.576
4
277
10.51
.818
5
278
10.55
.000
6
279
11.06
.691
7
280
8.38
.882
8
281
9.77
1.600
9
282
9.26
1.069
10
283
11.34
1.847
11
284
9.35
.629
12
285
8.89
2.033
13
286
8.53
1.088
14
287
3.31
1.014
15
288
0.00
.907
16
289
0.00
.291
17
290
3.40
1.589
18
291
2.72
.470
19
292
4.21
.853
Moonlight Barometric
Intensity
Rainfall
Press. (MB)
.0000
.0000
1013.93
.0086
.0000
1017.93
.0020
.0000
1018.17
.0172
.0000
1013.95
.0000
.1472
1015.03
.1061
.0000
1011.68
.1584
.0000
1015.91
.2324
.0000
1016.68
.0132
.0000
1016.18
.0188
.0000
1015.76
.2394
.0000
1013.74
.9310
.0000
1013.17
.6256
.0000
1013.71
.3513
.0000
1014.42
.0237
.0000
1018.45
.2838
.0000
1018.89
.2056
.0000
1016.83
.1276
.0000
1014.28
.0700
.0000
1013.71
.0420
.0000
1013.64
.0150
.0000
1015.99
.0080
.0000
1015.65
.0014
.0000
1013.49
.0029
.0000
1014.51
.0002
.0000
1014.32
.0000
.0000
1016.72
.0000
.0000
1021.34
.0000
.0000
1021.04
.0023
.0000
1021.04

- 235
Table D.8 (continued)
Calendar
Date
Julian
Date
Flight
Temp. (C)
Vapor
Press.
Deficit
(mm Hg)
Moonlight
Intensity
Rainfall
Barometric
Press. (MB)
Oct. 20
293
3.31
.723
.0031
.0000
1019.52
21
294
5.24
.293
.0051
.0000
1018.73
22
295
5.79
.058
.0009
.0005

APPENDIX E
PICTORIAL KEY OF SOME LEPIDOPTERA EGGS
FOUND ON SOYBEAN

Introduction
Egg density data were required to construct a model of adult
velvetbean caterpillar (VBC) oviposition in soybean (see Chapters V and
VI). Accurate estimation of VBC egg density depended on proper
identification of Lepidoptera eggs collected during sampling.
Mis-identification of VBC eggs could have led to inflated egg density
estimates. The present study was initiated to identify and describe
some Lepidoptera eggs found on soybean.
Materials and Methods
From 1980-82, the development and color changes of eggs of several
lepidoptera species were documented. Eggs were collected with four
different techniques: (1) colony adults* were allowed to oviposit on
soybean in the lab; (2) wild adults were collected from soybean and
allowed to oviposit on soybean in the lab; (3) wild adults were observed
to oviposit in the field; and (4) eggs were found on soybean and reared
to adults** (see Table E.l). All wild adults and eggs were obtained
from a 1 ha soybean field (cv. Bragg) at the University of Florida's
Green Acres Research Farm, Alachua County, FL (see Appendix A for
agronomic practices). All adults and eggs were maintained in the lab in
Percival Growth Chambers (Model I-35LL) at 26.7 1C, > 80% RH, and
14L:10D photoperiod and in the presence of a 7.5 w nightlight (General
Electric, 7.5 S/CW). Egg development and coloration were monitored with
a 70X dissecting microscope at variable time intervals. All eggs were
*Colony adults were obtained from Dr. N. C. Leppla, Research Scientist,
USDA Insect Attractants, Behavior, and Basic Biology Research
Laboratory, Gainesville, FL 32604.
**Eggs collected with the fourth technique were exposed to 2 1C for
ca. 4-12 h after collection (see Chapter V).
- 237 -

Table E.l. Techniques used to collect eggs of some Lepidoptera species found on soybean from 1980-82.
All eggs were laid on soybean. An "X" indicates that a particular technique was used for a
species.
Wild Eggs
Species Name
0
Colony
Eggs
Oviposition^
in Lab
Found in FieldC
(Oviposition
Observed)
Found in Field
(Oviposition
Not Observed)
Anticarsia gemmatalis Hubner
X
X
X
X
Plathypena scabra (Fabricius)
X
X
0
Mocis latipes (Guenee)
X
Pseudoplusia includens (Walker)
X
X
Heliothis zea (Boddie)^
X
X
X
Heliothis virescens (Fabricius)^
X
X
Urbanus proteus (Linnaeus)
X
X
Strymon melinus (Hubner)
X
Unknown
X
Colony adults were obtained from Dr. N. C. Leppla, Research Scientist, USDA Insect Attractants,
Behavior, and Basic Biology Research Laboratory, Gainesville, FL 32604.
^Wild adults were collected from soybean and allowed to oviposit on soybean in the lab.
c
Wild adults were observed to oviposit in the field.
238

Table E.l (continued)
Eggs were found on soybean. Eclosed larvae were reared on soybean to the adult stage.
6
M. latipes larvae could not be reared on soybean but were reared on sandbur, Cenchrus sp.
^Eggs of H. zea and H. virescens are not distinguishable.
g
S. melinus is a stem borer.

- 240 -
photographed with the following Olympus equipment (except where noted)
0M-2 35mm SLR Camera, Auto Bellows, Macro Lens (1:35, f = 20mm, 16 to
3.5 f stop), three Electronic Flash T32's, Control Box, Emerson
Micromanipulator, and Kodachrome64 slide film (KR 135-36).
Results and Discussion
A pictorial key to egg identification by species is presented on
the following pages.

- 241
Anticarsia gemmatalis Hubner
Common Name: Velvetbean Caterpillar.
Family: Noctuidae
Egg Development,
Color-Changes and Types:
Freshly Laid Light green, green, bluish green,
turquoise, or off white [Fig. E.l(A)].
Middle Aged Same as freshly laid but with speckles.
Speckles are small, irregular in shape
and reddish brown, brownish red, ochre
or (rarely) off white [Fig. E.l(B)].
After speckling occurs larvae develop
an eye spot (i.e., six stemmata) that
is visible at the edge of the
micropylar area [Fig. E.l(C), see tiny
dark brown spots that form a small
crescent].
Old (Pre-Eclosion) Light brown with a visible larval
head-capsule, eyes and mandibles [Fig.
E.l(D)].
Eclosed Whitish [Fig. E.l(E)]. Usually the
chorion was eaten by a larva.
Parasitized Black [Fig. E.1(F and G) ].
Black with hole in egg [Fig. E.l(H)].
Parasitoid Emerged

- 242
Egg Shape: Top View
.. Circular.
Side View
.. Dome like or half a circle.
Ridge Number:
x SD = 2.81 2.3, range 21-32, n =
22.
Ridge Morphology:
Distinct, easy to count.
Micropylar Area:
Flat and circular. Sometimes a series
of small circles can be seen.
Spatial Occurrence:
Eggs laid singly.
Similar Eggs and Differences:
M. latipes
.. Large reddish brown splotches,
micropylar area is larger and not as
defined, egg looks circular from side
view.
P. scabra
,. About half the number of ridges.
Ridges protrude well above egg surface

- 243 -
Figure E.l. A. gemmatalis eggs: (A) freshly laid, (B) middle aged, (C)
middle aged with eye spot, (D) old or pre-eclosion, (E)
eclosed, (F) parasitized, (G) parasitized, and (H)
parasitoid emerged.

244 -
Figure E.l (continued)

- 245 -
Figure E.l (continued)

246 -
Plathypena scabra (Fabricius)
Common Name:
Green Cloverworm.
Family:
Noctuidae.
Egg Development,
Color-Changes and Types:
Freshly Laid
. Light green, off white [Fig. E.2(A)].
Middle Aged
. Same as freshly laid but with speckles
Speckles are small, irregularly shaped
and reddish brown [Fig. E.2(B)].
Old (Pre-Eclosion)
. Light brown with a visible larval
head-capsule, eyes and mandibles [Fig.
E.2(C)].
Parasitized
. Black [Fig. E.2(D and E)].
Parasitoid Emerged
. Black with hole in side [Fig. E.2(F)].
Egg Shape: Top View
. Circular.
Side View
. Flattened dome or half circle. Egg in
Fig. E.2(E) was removed from substrate
and positioned for photograph. The
bottom of this egg looks circular but
was flat when attached to the
substrate.
Ridge Number:
x SD = 16.5 1.4, range 14-19, n =
38.
Ridge Morphology:
Protrude well above egg surface (i.e.,
fin like). Easy to count.
Micropylar Area:
Flat, composed of concentric circles.

247 -
Spatial Occurrence: Eggs laid singly.
Similar Eggs and Differences: A. gemmatalis and M. latipes have about
twice as many ridges.

248 -
Figure E.2. P. scabra eggs: (1) freshly laid, (B) middle aged, (C) old
or pre-eclosion, (D) parasitized, (E) parasitized, and (F)
parasitoid emerged.

249 -
Figure E.2 (continued)

250 -
Mocis latipes (Guenee)
Common Name:
Striped Grass Looper.
Family:
Noctuidae.
Egg Development,
Color-Changes and Types:
Freshly Laid
.. Green, light green, bluish green [Fig.
E. 3(A)].
Middle Aged
.. Same as freshly laid but with large
reddish brown splotches. Splotches are
hexagonal or undefined in shape and are
brown, reddish brown, or brownish red
[Fig. E.3(B and C)].
Old (Pre-Eclosion)
.. Unknown.
Parasitized
.. Black [Fig. E.3(D and E)].
Parasitoid Emerged
.. Black (sometimes ridges look whitish)
with hole in egg [Fig. E.3(F)].
Egg Shape: Top View
.. Circular.
Side View
.. Circular.
Ridge Number:
x SD = 32.1 1.24, range 30-34, n =
8.
Ridge Morphology:
Distinct, easy to count.
Micropylar Area:
Flat, composed of small circles.
Spatial Occurrence:
Eggs laid singly and in groups of two
or three.
Similar Eggs and Differences:
A. gemmatalis
.. Small reddish brown speckles, smaller
and more defined microphylar area,
dome-like side view.

- 251
scabra Approximately half the number of
ridges, ridges protrude well above egg
surface.

252 -
Figure E.3. M. latipes eggs: (A) freshly laid, (B) middle aged, (C)
middle aged, (D) parasitized, (E) parasitized, and (F)
parasitoid emerged.

253 -
Figure E.3 (continued)

- 254 -
Pseudoplusia includens (Walker)
Common Name:
Soybean Looper.
Family:
Noctuidae.
Egg Development,
Color-Changes and Types:
Freshly Laid
Off white, light green. Tends to
reflect small patches of color that are
iridescent or opal like [Fig. E.4(A)].
Middle Aged
Same as freshly laid.
Old (Pre-Eclosion)
Light brown with a visible larval
head-capsule, eyes and mandibles [Fig.
E.4(B)].
Parasitized
Black [Fig. E.4(C-G)].
Parasitoid Emerging
Black [Fig. E.4 (D-G)].
Parasitoid
Trichogramma sp. [Fig. E.4(E-H)].
Egg Shape: Top View
Circular.
Side View
A flattened dome or half circle. Egg
in Fig. E.4(D) was removed from
substrate and positioned for
photograph.
Ridge Number:
x SD = 34.1 2.8, range 30-40, n =
19.
Ridge Morphology:
Not distinct, very difficult to count.
Micropylar Area:
Flat, very undefined, very difficult to
see. Ridges appear to gradually
diminish into center of micropylar
area.

255
Spatial Occurrence: Eggs laid singly.
Similar Eggs and Differences: Other loopers, but none were observed.

256 -
Figure E.4. P. includens eggs: (A) freshly laid, (B) old or
pre-eclosion, (C) parasitized, (D)-(G) parasitoid emerging,
and (H) parasitoid.

- 257 -
Figure E.4 (continued)

- 258 -
Figure E.4 (continued)

259 -
Heliothis zea (Boddie)
Common Names:
Bollworm, Corn Earworm, Tomato
Fruitworm.
Heliothis virescens (Fabricius)
Common Name:
Tobacco Budworm.
Note: The eggs of these two species were indistinguishable.
Family:
Noctuidae.
Egg Development,
Color-Changes and Types:
Freshly Laid
Creamy white, yellowish white, off
white, whitish [Fig. E.5(A)].
Middle Aged
Same as freshly laid but with colored
band around equator. Band is vaguely
defined and reddish brown, brownish
brown or brown [Fig. E.5(B)].
Old (Pre-Eclosion)
Creamy white with black larval head
capsule.
Parasitized
Black [Fig. E.5(C and D)].
Parasitoid Emerged
Black or grayish with hole in egg [Fig.
E. 5(E) ].
Egg Shape: Top View
Circular.
Side View
Barrel shaped.
Ridge Number:
x SD = 24.7 1.5, range 21-28, n =
18.
Ridge Morphology:
Distinct, easy to count.

260 -
Micropylar Area:
Spatial Occurrence:
Similar Eggs and Differences:
U. proteus
Raised, doughnut shaped or inverted
nipple. Side view shows raised
micropylar area [Fig. E.5(D)].
Laid singly.
.. Has very few ridges.

- 261
. H. zea or H. virescens eggs: (A) freshly laid, (B) middle
aged, (C) parasitized, (D) parasitized, and (E) parasitoid
emerged.
Figure E.5

262 -
Figure E.5 (continued)

- 263 -
Urbanus proteus (Linnaeus)
Common Names:
Bean Leafroller, Longtailed Skipper.
Family:
Hesperiidae.
Egg Development,
Color-Changes and Types:
Freshly Laid
.. Creamy white, yellowish white, off
white, whitish [Fig. E.6(A and B)].
Middle Aged
.. Same as freshly laid.
Old (Pre-Eclosion)
.. Yellowish with black larval head
capsule [Fig. E.6(C)].
Eclosed
.. Whitish [Fig. E.6(D)]. Larvae ate only
the top portion of the chorion.
Parasitized
.. Never observed.
Egg Shape: Top View
.. Circular.
Side View
.. Barrel shaped.
Ridge Number:
x SD = 11.6 0.7, range 10-13, n =
46.
Ridge Morphology:
Distinct, easy to count.
Micropylar Area:
Flat, large, circular and smooth.
Spatial Occurrence:
Laid singly but usually laid in groups
of two or three and attached to each
other.
Similar Eggs and Differences:
H. spp
Have twice as many ridges.

- 264 -
Figure E.6. U. proteus eggs: (A and B) freshly laid, (C) old or
pre-eclosion, and (D) eclosed.

- 265 -
Figure E.6 (continued)

- 266 -
Strymon melinus (Hubner)
Common Name:
Family:
Egg Development,
Color-Changes and Types:
Egg Shape: Top View
Side View
Ridge Number:
Chorion Morphology:
Micropylar Area:
Spatial Occurrence:
Similar Eggs and Differences:
Gray Hairstreak.
Lycaenidae.
Unknown, but observed eggs were whitish
green [Fig. E.7(A)]. Eclosed eggs were
whitish. Not known if chorion usually
is eaten [Fig. E.7(B)].
Circular
Not distinct.
Not countable or observable.
Egg surface is covered with tiny
outward projections of the chorion.
Not distinct.
Eggs laid singly.
Other hairstreaks, but none were
observed.

267 -
Figure E.7. >. melinus eggs:
(A) unhatched and (B) eclosed.

- 268 -
Unknown Species
Common Name:
Unknown.
Family:
Noctuidae (?).
Egg Development,
Color-Changes and Types:
Freshly Laid
.. Whitish, grayish white, yellowish white
[Fig. E.8(A)].
Middle Aged
. Same as freshly laid but with reddish-
brown band around egg and reddish-brown
splotch under the microphylar area
[Fig. E.8(B)].
Old (Pre-Eclosion)
.. Unknown.
Parasitized
.. Black [Fig. E.8(C)].
Egg Shape: Top View
.. Circular.
Side View
.. Dome like.
Ridge Number:
26, n = 1.
Ridge Morphology:
Distinct, easy to count.
Micropylar Area:
Nipple like.
Spatial Occurrence:
Eggs laid singly.
Similar Eggs and Differences:
Unknown.

- 269 -
Figure E.8.
Eggs of unknown species: (A) freshly laid, (B) middle
aged, and (C) parasitized.

270 -
Unknown Species
Common Name:
Unknown.
Family:
Noctuidae (?).
Egg Development,
Color-Changes and Types:
Parasitoid Emerged
.. Black with hole in egg [Fig. E.9(A)]
Egg Shape: Top View
.. Circular.
Side View
.. Not recorded.
Ridge Number:
28, n = 1.
Ridge Morphology:
Distinct, easy to count.
Micropylar Area:
Depressed.
Spatial Occurrence:
Egg laid singly.
Similar Eggs and Differences:
Unknown.

271
Figure E.9. Egg of unknown species (parasitoid emerged).

APPENDIX F
EGG DENSITY DATA

Table F.l. Mean number of freshly-laid velvetbean caterpillar
eggs per soybean plant (1981) found in a 1 ha
soybean field at the Green Acres Research Farm,
Alachua County, FL.
Calendar
Date
Julian
Date
Sample
Size
c
, Sample
! Unit
: Size
Mean No.
of Eggs/Plant
( SD)
June 23
173
30
1
.000 .000
25
176
30
1
.000 .000
29
180
30
1
.000 .000
July 6
187
30
1
.000 .000
9
190
30
1
.000 .000
12
194
30
1
.000 .000
16
197
30
1
.000 .000
20
201
30
1
.000 .000
23
204
30
1
.033 .183
27
208
70
1
.029 .168
30
211
70
1
.014 .120
Aug. 3
215
70
1
.029 .168
6
218
70
1
.014 .120
10
222
70
1
.086 .282
13
225
70
1
.086 .329
17
229
70
1
.203 .558
20
232
70
1
.200 .651
24
236
70
1
.101 .349
27
239
70
1
.214 .478
31
243
70
1
.203 .472
Sept. 3
246
70
1
.243 .494
7
250
70
1
.271 .658
14
257
70
1
.435 .630
aMean number
of soybean plants
per 0.91 m-row was
28.267.
^Sample size
was the
number of
plants sampled.
Q
Sample unit
size was
based on
an individual soyb
ean plant;
i.e., the sample unit size was
one soybean plant

273 -

- 274 -
Table F.2. Mean number of freshly-laid velvetbean caterpillar
eggs per soybean plant (1982) found in a 1 ha
soybean field at the Green Acres Research Farm,
Alachua County, FL.
Calendar
Date
Julian
Date
Sample*3
Size
c
Sample
Unit
Size
Mean No.
of Eggs/Plant
( SD)
June 21
172
70
1
.000
+
.000
25
176
70
2
.000
+
.000
28
179
70
2
.000
+
.000
July 2
183
70
2
.000
+
.000
5
186
70
2
.014
+
.014
9
190
70
2
.000
+
.000
12
193
70
2
.000
+
.000
16
197
70
2
.043
+
.042
19
200
70
2
.029
+
.028
23
204
70
2
.071
+
.096
26
207
70
2
.357
+
.523
30
211
70
2
.557
+
.801
Aug. 2
214
70
2
.857
+
1.458
6
218
70
1
.500
+
.544
9
221
70
1
.557
+
.772
13
225
50
1
.840
+
1.239
16
228
41
1
.854
+
1.478
20
232
30
1
1.100
+
1.269
23
235
30
1
1.333
+
1.709
27
239
30
1
1.400
+
1.379
30
242
30
1
1.300
+
1.784
Sept. 3
246
30
1
.633
+
.890
6
249
30
1
.733
+
.944
10
253
30
1
.933
+
1.143
13
256
30
1
.800
+
1.127
17
260
30
1
.767
+
1.194
20
263
30
1
1.833
+
2.718
24
267
30
1
.767
+
.898
27
270
30
1
.800
+
1.243
Oct. 1
274
30
1
.567
+
.817
4
277
30
1
.667
+
1.729
8
281
30
1
.067
+
.254
11
284
30
1
.133
+
.316
15
288
30
1
.000
+
.000
^ean number of soybean.plants per 0.91 m-row was 12.733.
^Sample size was the number of plants sampled,
c
Sample unit size was based on individual soybean plants; i.e.,
the sample unit size varied from one to two plants.

APPENDIX G
SAS PROGRAMS AND DATA FILES FOR MODEL
OF ADULT AND EGG POPULATIONS

Table G.l. SAS program of 1981 model of adult and egg populations of
velvetbean caterpillar. Data file of the model is listed in
Table G.2.
//PM0DEL81 JOB (1001,2064,5,5,0),'BMG',CLASS=A,MSGLEVEL=(2,0)
/*PASSWORD
/*R0UTE PRINT LOCAL
//EXEC SAS,REGI0N=800K
***********************************************************************
*** PM0DEL81 = PROGRAM, MODEL, 1981 ***
***********************************************************************j
***********************************************************************
***
IN THE INPUT
STATEMENT:
***
***
JULIAN
=
Julian date.
***
***
FBLT
=
Total number of females captured in BLT

***
***
LB05
=
I^ower bound of 95% confidence
interval,
egg
***
***
density per .91 m-row.
***
***
EEGG
=
Estimated egg density per .91
m-row.
***
***
UB05
=
Upper bound of 95% confidence
interval,
egg
***
***
density per .91 m-row.
***
***
SOY
=
Soybean phenological stage.
***
***********************************************************************.
>
***********************************************************************
***
IN THE EQUATIONS:
***
***
FTOTAL
=
Total number of females in the field.
***
***
VF
=
Virgin females, proportion of females that
***
***
are not mated.
***
***
MORT
=
Mortality (proportional) of mated females
***
per day.
***
***
OVI
=
Total number of eggs laid per female.
***
***
TEGG
=
Total number of eggs laid in the field.
***
***
PEGG
=
Predicted egg density per .91 m-row. The
***
***
constant, 11935.696, represents the total
***
***
number of .91 m-row sections of soybean in
***
***
the field.
***
***********************************************************************.
DATA BG1;
INPUT JULIAN FBLT LB05 EEGG UB05 SOY;
FTOTAL = 134.11 + 23.20*FBLT;
VF = 0;
MORT = 0;
If
1
<
= SOY
<
=
5
THEN
OVI
=
0
If
5
<
SOY
<
=
9
THEN
OVI
=
40
If
9
<
SOY
<
=
14
THEN
OVI
=
220
If
14
<
SOY
<
=
15
THEN
OVI
=
80
If
15
<
SOY
<
=
17
THEN
OVI
=
210
If
17
<
SOY
<
=
19
THEN
OVI
=
60
If
19
<
SOY
<
=
20
THEN
OVI
=
0
276 -

277
Table G.l (continued)
TEGG = FTOTAL (1-VF) (1-MORT) OVI;
PEGG = TEGG/11935.696;
CARDS;
/*INCLUDE DMODEL81.DAT
********* *********** 'k-kk&£&*'k'k'k'J *** DATA FILE IS DMODEL81.DAT ***
***********************************
>
OPTIONS NOCENTER;
PROC PRINT DATA=BG1;
VAR JULIAN SOY FBLT FTOTAL VF MORT OVI TEGG LB05 EEGG UB05 PEGG
TITLE 'MODEL 1981';
PROC PLOT DATA=BG1;
PLOT LB05*JULIAN='-'
EEGG*JULIAN='E'
UB05*JULIAN='-'
PEGG*JULIAN='P'/OVERLAY;
TITLE 'MODEL 1981';
*** THIS IS FILE PMODEL81 ***;
/*

- 278
Table G.2. Data set (DM0DEL81.DAT) for 1981 model of adult and egg
populations of velvetbean caterpillar. See the comment
statements in Table G.l for definitions of the column
headings.
JULIAN
FBLT
LB05
EEGG
UB05
SOY
173
0
0.00
0.00
0.00
1
174
0

1
175
0

1
176
0
0.00
0.00
0.00
1
177
0



1
178
0



1
179
0


1
180
0
0.00
0.00
0.00
2
181
0



2
182
0



2
183
0


2
184
0



2
185
0



2
186
0



2
187
0
0.00
0.00
0.00
3
188
0



3
189
0



3
190
0
0.00
0.00
0.00
4
191
0



4
192
0



4
193
0


4
194
0
0.00
0.00
0.00
5
195
0



5
196
0



5
197
0
0.00
0.00
0.00
6
198
0


6
199
0



6
200
0



6
201
0
0.00
0.00
0.00
7
202
0



7
203
1



7
204
0
0.00
0.94
2.79
7
205
1


7
206
0



7
207
0


7
208
1
0.00
0.81
1.92
11
209
1



11
210
0



11
211
0
0.00
0.40
1.20
11
212
0



11
213
1



11
214
0



11

215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
- 279 -
(continued)
FBLT
LB05
EEGG
UB05
SOY
0
0.00
0.81
1.92
11
1
11
1
11
2
0.00
0.40
1.20
11
2

11
2

11
3

11
2
0.56
2.42
4.29
12
0

12
0

12
4
0.24
2.42
4.60
12
3

12
4

12
1

12
7
2.04
5.73
9.43
12
9

12
15

12
8
1.35
5.65
9.96
13
6
13
5
13
12
13
4
0.55
2.87
5.18
14
10
14
3
14
7
2.89
6.06
9.23
14
14

14
22

14
8

14
3
2.61
5.74
8.86
15
14
15
21
15
18
3.59
6.87
10.14
15
11
15
18

15
21

15
6
3.32
7.67
12.03
15
10
15
16
15
20

15
18

15
37

15
14
15
30
8.12
12.29
16.46
16

- 280 -
Table G.3. SAS program of 1982 model of adult and egg populations of
velvetbean caterpillar. To run the model without a variable
oviposition rate replace the present OVI function with the
phrase "OVI = 220;". Data file of the model is listed in
Table G.4.
//PMODEL82 JOB (1001,2064,5,5,0),'BMG',CLASS=A,MSGLEVEL=(2,0)
/*PASSWORD
/*R0UTE PRINT LOCAL
//EXEC SAS,REGI0N=800K
*************** ******** ******
*** PMODEL82 = PROGRAM, MODEL, 1982 ***
***********************************************************************.
***********************************************************************
***
***
***
***
***
***
***
***
***
IN THE INPUT
JULIAN =
FBLT =
LB05 =
STATEMENT:
Julian date.
Total number of females captured in BLT.
Lower bound of 95% confidence interval, egg
density per .91 m-row.
EEGG = Estimated egg density per .91 m-row.
UB05 = Upper bound of 95% confidence interval, egg
density per .91 m-row.
SOY = Soybean phenological stage.
***
***
***
***
***
***
***
***
***
***********************************************************************
***********************************************************************
***
IN THE EQUATIONS:
***
***
FTOTAL
=
Total number of females in the field.
***
***
VF
=
Virgin females, proportion of females that
***
***
are not mated.
***
***
MORT
=
Mortality (proportional) of mated females
***
***
per day.
***
***
OVI
=
Total number of eggs laid per female.
***
***
TEGG
=
Total number of eggs laid in the field.
***
***
PEGG
=
Predicted egg density per .91 m-row. The
"k*f*
***
constant, 12469.859, represents the total
***
***
number of .91 m-row sections of soybean in
***
***
the field.
***
it**********************************************************************.
DATA BG1;
INPUT JULIAN FBLT LB05 EEGG UB05 SOY;
FTOTAL = 134.11 + 23.20*FBLT;
VF = 0;
MORT = 0;

281
Table G.3 (continued)
If
1
< =
SOY
<
=
5
THEN
OVI
=
0
If
5
<
SOY
<
=
9
THEN
OVI
=
40
If
9
<
SOY
<
=
14
THEN
OVI
=
220
If
14
<
SOY
<
=
15
THEN
OVI
=
80
If
15
<
SOY
<
=
17
THEN
OVI
=
210
If
17
<
SOY
<
=
19
THEN
OVI
=
60
If
19
<
SOY
<
=
20
THEN
OVI
=
0
EGG = FTOTAL (1-VF) (1-MORT) OVI;
PEGG = TEGG/12469.859;
CARDS;
/INCLUDE DMODEL82.DAT
***********************************
*** DATA FILE IS DMODEL82.DAT ***
************************************
OPTIONS NOCENTER;
PROC PRINT DATA=BG1;
VAR JULIAN SOY FBLT FTOTAL VF MORT OVI TEGG LB05 EEGG UB05 PEGG
TITLE 'MODEL 1982';
PROC PLOT DATA=BG1;
PLOT LB05*JULIAN='-'
EEGG*JULIAN='E'
UB05*JULIAN='-'
PEGG*JULIAN='P'/OVERLAY;
TITLE 'MODEL 1982';
*** THIS IS FILE PMODEL82 ***;
/*

175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
- 282
Data set (DMODEL82.DAT) for 1982 model of adult and egg
populations of velvetbean caterpillar. See the comment
statements in Table G.3 for definitions of the column
headings.
FBLT
LB05
EEGG
UB05
SOY
0
0.00
0.00
0.00
1
0

1
0

1
0

1
0
0.00
0.00
0.00
1
0

1
0

1
0
0.00
0.00
0.00
2
0

2
0

2
0

2
0
0.00
0.00
0.00
3
0

3
0

3
0
0.00
0.09
0.27
4
0

4
0

4
0

4
1
0.00
0.00
0.00
5
1

5
0

5
2
0.00
0.00
0.00
5
0

5
0

5
0

5
0
0.00
0.27
0.58
6
1

6
0

6
0
0.00
0.18
0.43
7
4

7
2

7
1

7
2
0.00
0.45
0.92
8
1 '

8
0

8
2
1.20
2.27
3.35
10
4
10
6
10
5
10
2
2.21
3.55
4.88
11
0
11
2
11

214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
- 283 -
(continued)
FBLT
LB05
EEGG
UB05
SOY
6
3.66
5.46
7.26
11
4

11
1


11
10


11
2
4.17
6.37
8.57
12
3


12
10


12
16
4.47
7.09
9.71
12
21


12
15


12
10


12
11
6.77
10.70
14.62
12
15


12
20


12
31
6.13
10.87
15.61
13
51

13
37


13
48


13
37
8.23
14.01
19.79
14
24


14
19


14
24
9.19
16.97
24.76
14
28


14
26


14
19


14
75
11.54
17.83
24.11
15
43

15
64

15
106
8.42
16.55
24.68
15
75


15
97


15
75


15
75
4.01
8.06
12.12
15
50


15
53


15
62
5.03
9.34
13.64
15
41


15
72


15
52

15
141
6.68
11.88
17.09
15
81

15
43

15
33
5.05
10.19
15.32
16
57

16
51

16

259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
- 284 -
(continued)
FBLT
LB05
EEGG
UB05
SOY
39
16
31
4.32
9.76
15.20
16
39


16
29


16
24
10.96
23.34
35.72
16
27
16
28


16
15


16
13
5.67
9.76
13.85
17
38


17
46


17
3
4.52
10.19
15.85
17
10


17
35


17
57

17
60
3.49
7.22
10.94
18
23



18
23



18
26
0.61
8.49
16.37
18
43



18
24



18
13



18
12
0.00
0.85
2.01
18
14



18
20



18
16
0.26
1.70
3.14
19
17


19
54


19
18

19
26
0.00
0.00
0.00
20

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