Title: Florida Entomologist
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Title: Florida Entomologist
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Creator: Florida Entomological Society
Publisher: Florida Entomological Society
Place of Publication: Winter Haven, Fla.
Publication Date: 1997
Copyright Date: 1917
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Subject: Florida Entomological Society
Entomology -- Periodicals
Insects -- Florida
Insects -- Florida -- Periodicals
Insects -- Periodicals
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General Note: Eigenfactor: Florida Entomologist: http://www.bioone.org/doi/full/10.1653/024.092.0401
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Jansson et al.: Novel Formulation for Emamectin Benzoate 425

DEVELOPMENT OF A NOVEL SOLUBLE GRANULE
FORMULATION OF EMAMECTIN BENZOATE FOR CONTROL
OF LEPIDOPTEROUS PESTS

RICHARD K. JANSSON,1 ROBERT F. PETERSON,2 PRADIP K. MOOKERJEE,2
W. ROSS HALLIDAY,3 JOSEPH A. ARGENTINE3 AND RICHARD A. DYBAS2
Merck Research Laboratories, P.O. Box 450, Hillsborough Road
Three Bridges, NJ 08887-0450

'Current Address: Rohm and Hass Co. Research Laboratories, 727 Norristown Road
Spring House, PA 19477

'Current Address: Lonza, Inc., Lonza Research and Development, 79 Route 22 East
Annandale, NJ 08801

3Ricerca, Inc., 7528 Auburn Road, P.O. Box 1000, Painesville, OH 44077

ABSTRACT

Six solid formulations of emamectin benzoate (one wettable powder (WP) blend,
one wettable dispersible granule (WG), and four soluble granules (SG)) were com-
pared with an emulsifiable concentrate (EC) formulation for their residual effective-
ness at controlling tobacco budworm, Heliothis virescens (F.), beet armyworm,
Spodoptera exigua (Hibner), and cabbage looper, Trichoplusia ni (Hibner), in three
glasshouse tests. Emamectin benzoate was applied to plants at two rates in each trial
(8.4 and 0.084 g ai/ha). Results from the glasshouse studies showed that most formu-
lations were comparable at controlling all lepidopterous pests tested. Four field trials
conducted in Florida confirmed that all formulations were comparable in their effec-
tiveness at controlling populations of lepidopterous pests on vegetables, including di-
amondback moth, Plutella xylostella (L.), on cabbage, southern armyworm,
Spodoptera eridania (Cramer), on pepper, and T. ni and S. exigua on celery. These
studies identified a novel SG formulation of emamectin benzoate that was comparable
to the EC formulation in its effectiveness at controlling lepidopterous pests, but supe-
rior to the EC in terms of safety to man and the environment. This novel SG formula-
tion is currently being developed for control of lepidopterous pests on a variety of
crops.

Key Words: Avermectin, emamectin benzoate, formulation, residual efficacy

RESUME

El efecto residual de seis formulaciones solidas de benzoato de emamectina (una
mezcla de polvo humedecible, granulos humedecibles dispersables, y cuatro granulos
solubles) fue comparado con el de un concentrado emulsificable en el control de Helio-
this virescens (F.), Spodoptera exigua (Hibner) y Trichoplusia ni (Hibner) en tres
pruebas, en tres invernaderos. El benzoato de emamectina fue aplicado a las plants
a dos concentraciones en cada prueba (8.4 y 0.084 g ia/ha). Los resultados de los estu-
dios de invernadero mostraron que la mayoria de las formulaciones fueron compara-
bles con en el control de todos los lepid6pteros probados. Cuatro pruebas de campo
conducidas en la Florida confirmaron que todas las formulaciones fueron comparable
en su efectividad al controlar poblaciones de lepid6pteros plagas de vegetables, inclu-
yendo Plutella xylostella (L.), en col, Spodoptera eridania (Cramer) en pimiento, y T.
ni y S. exigua en apio. Los studios identificaron una nueva formula de granulos solu-

















Florida Entomologist 80(4)


bles de benzoato de emamectina que fue comparable con el concentrado emulsionable
en cuanto a su efectividad al controlar lepid6pteros plagas pero es superior al concen-
trado emusionable en t6rminos de seguridad al hombre y el ambiente. Esta nueva for-
mulaci6n de granulos soluble es actualmente desarrollada para el control de
lepid6pteros plagas de various cultivos.




Avermectins, a family of 16-membered macrocyclic lactones produced by the soil mi-
croorganism, Streptomyces avermitilis MA-4680 (NRRL 8165), are an important tool in
animal health, human health and crop protection (Jansson & Dybas 1997). The major
component of the fermentation, avermectin B, (= abamectin), is a mixture of B,, (> 80%)
and Blb ( plications of avermectins for control of arthropods have been reviewed extensively
(Campbell et al. 1984, Dybas 1989, Lasota & Dybas 1991, Jansson & Dybas 1997).
Emamectin benzoate (MK-0244; PROCLAIMT') is a semisynthetic derivative of
abamectin and is currently being developed for control of lepidopterous pests on a va-
riety of vegetable crops worldwide (Dybas et al. 1989, Jansson & Dybas 1997, Jansson
et al. 1997). Impressive, broad spectrum control of lepidopterous pests on a variety of
vegetable crops in the field has been demonstrated at low use rates (8.4-16.8 g ai/ha)
(Jansson & Lecrone 1992, Leibee et al. 1995, Jansson et al. 1996, 1997, Jansson & Dy-
bas 1997).
Earlier attempts to develop solid formulations of avermectin insecticides failed
due to their low water solubility and selection of unsuitable delivery systems. This
was especially difficult with abamectin, which is about 3-fold less soluble in water
than emamectin benzoate (Merck, unpublished data). Recently, Jansson et al. (1996)
found that wettable powder (WP) formulations of emamectin benzoate had potential
for controlling lepidopterous pests on vegetables under glasshouse and field condi-
tions. It is well known that changes in the constituents of formulations may have
marked effects on the behavior of arthropods and concomitant product efficacy (Hart-
ley & Graham-Bryce 1980, Edwards et al. 1994). Additionally, changes in formulation
composition can significantly affect the overall safety of pesticide products to man and
the environment (Hudson & Tarwater 1988). The present studies extended our earlier
work (Jansson et al. 1996) to develop a novel solid formulation of emamectin benzoate
that was as effective as a liquid emulsifiable concentrate (EC) formulation at control-
ling lepidopterous pests. The soluble granule (SG) formulations reported herein are
novel to the agrichemical industry and represent a significant breakthrough in aver-
mectin delivery systems for agriculture.

MATERIALS AND METHODS

Formulations Tested

Experimental formulations tested were of three types: dry powder blends, wetta-
ble dispersible granules, and soluble granules (Table 1); each of these was compared
with the effectiveness of a 0.16 EC formulation at controlling lepidopterous pests. The
dry powder blend (formulation 81) was prepared by combining all ingredients (ai, di-
luent, surfactant) and then blending until homogeneous. The wettable dispersible
granule (WG) (83) and soluble granule (SG) formulations (85, 86, 87, 88) were pre-
pared by combining all ingredients (ai, diluents, surfactants), blending until homoge-
neous, and then granulating. The EC formulation (formulation 49) was prepared by


December, 1997

















Jansson et al.: Novel Formulation for Emamectin Benzoate 427

TABLE 1. FORMULATION TYPE, COMPOSITION, AND PERCENTAGE OF AVAILABLE AI OF
SEVEN FORMULATIONS OF EMAMECTIN BENZOATE (MK-0244) TESTED IN
GLASSHOUSE AND FIELD TRIALS.

%
available
Treatment Formulation type Composition Trials' ai

MK-0244-81 2 WP Dry powder blend ai, diluents, GH 1,2; F 1-3 47
surfactants
MK-0244-83 5 WG Wettable granule ai, solvents, GH 1,2; F 1-3 > 95
carrier,
surfactants
MK-0244-85 5 SG Soluble granule ai, soluble GH 1,2,3; F 1-4 > 95
diluents,
surfactants
MK-0244-86 5 SG Soluble granule ai, diluents, GH 3; F 4 > 95
surfactants
MK-0244-87 5 SG Soluble granule ai, diluents, GH 3; F 4 > 95
surfactants
MK-0244-88 5 SG Soluble granule ai, soluble GH 3; F 4 > 95
diluents,
surfactants
MK-0244-49 0.16 EC Emulsifiable ai, solvents, GH 1,2,3; F 1-4 > 95
concentrate surfactants

1GH, Glasshouse; F, Field; numbers correspond to trial number (e.g., GH 1,2,3 = trials 1, 2, and 3 in the glass-
house).


combining all ingredients and stirring until all solids had dissolved as described pre-
viously (Jansson et al. 1996). The EC formulation (0.16 EC) and the dry powder blend
contained 2.0-2.2% w/w of emamectin benzoate. The WG and SG formulations con-
tained 4.8-5.2% w/w of emamectin benzoate.
Chemical availability, or the percentage of ai in solution within one hour after dis-
solving in water, was estimated for all formulations tested using methods described
previously (Jansson et al. 1996). Estimates for percentages of available emamectin
benzoate in solution that were > 95% could not be measured accurately based on the
methods used.


Glasshouse Tests

Methods used in all glasshouse tests were similar to those described previously
(Jansson et al. 1996). Three trials were conducted to compare the residual efficacy of
the six solid formulations of emamectin benzoate with the EC formulation (Table 1).
Formulations tested in each trial are given in Table 1. In all three trials, formulations
of emamectin benzoate were applied to plants at two rates: the proposed field use rate
(8.4 g ai/ha) and 1% of this rate (0.084 g ai/ha).
Residual efficacy of each formulation was evaluated by challenging neonates of
three lepidopterous pests, tobacco budworm, Heliothis virescens (F.), beet armyworm,
Spodoptera exigua (Hiibner), and cabbage looper, Trichoplusia ni (Hiibner). Heliothis
virescens was tested on two-week old chickpea, Cicer arietinum cv. Burpee Garbanzo
5024, plants; T. ni was tested on two-week old cabbage, Brassica oleracea var. capitata

















Florida Entomologist 80(4)


L. cv. Early Jersey Wakefield, plants; and S. exigua was tested on five-week old pepper,
Capsicum annuum L. cv. Pimento, plants, two-week old sugarbeet, Beta vulgaris L. cv.
USH-11, plants, or excised leaves of scarlet runner bean, Phaseolus coccineum L. Cut-
tings from scarlet runner bean were excised when plants were approximately 6-8 days
old, placed in an AquapicM containing deionized water, and subsequently sprayed
with the various formulations as described previously (Jansson et al. 1996).
Plants were sprayed with different formulations of emamectin benzoate using a
track-sprayer system that delivered 153.2 liters/ha at 3.4 kg/cm2 and at 3.5 km/h (Jan-
sson et al. 1996). All formulations were applied in combination with a nonionic sur-
factant (0.0625%; Leaf Act 80A, PureGro Co., West Sacramento, CA). In all three
trials, 100 plants for each species were treated with two rates of each formulation us-
ing a CO, track-sprayer system described previously (Jansson et al. 1996). Plants
were air-dried after applications were made and then moved to a glasshouse (trials 1
and 2) for the duration of the experiment. In the third trial, plants were moved out-
doors after they were air-dried. All plants were bottom watered to minimize wash-off
of emamectin benzoate from foliage. Ten plants were randomly selected from each
treatment on days 0, 4, 7, 10, 14, 17, and 21. One representative leaf was randomly ex-
cised from each plant and placed in water agar dishes. Approximately ten neonates
were placed in each dish on each sample date; mortality was recorded after 96 hours.
High control mortality was found in the second trial. For this reason, an additional
test was conducted using a miniature volume assay similar to that described previ-
ously (Jansson et al. 1998). Formulations 81, 83, 85 and the EC (49) were applied at
two concentrations (4 and 20 ng/ml [ppb]) to foliage of scarlet runner bean, Phaseolus
coccineum L., 'Pimento' pepper, and chickpea using an airbrush applicator and then
challenged with neonate S. exigua (scarlet runner and pepper) and H. virescens
(chickpea) using methods described previously (Jansson et al. 1998). Mortality of lar-
vae was recorded on 0, 3, and 7 days after application (DAA). Approximately 100 ne-
onates were tested per treatment combination per evaluation time.

Field Tests

Four field tests were conducted in 1994 and 1995 in Florida. Experimental formu-
lations were compared with the EC formulation at the proposed use rate (8.4 g ai/ha).
In all except the last field test, formulations were applied at 7- and 14-day intervals.
Tests were conducted in Loxahatchee, FL, in two commercial cabbage, B. oleracea var
capitata cv. Monument, fields; in Belle Glade, FL in a commercial celery, Apium gra-
veolens L. cv. Florida 683 K-strain, field; and in Immokalee, FL, in a commercial bell
pepper, C. annuum var. annuum L. cv. California Wonder, field. Formulations 81, 83,
85 and the EC (49) were tested in the first three trials (celery, pepper and one cabbage
trial); formulations 85, 86, 87 and 88 were tested in the last trial on cabbage. All for-
mulations were applied in combination with a nonionic surfactant (0.0625%; Leaf Act
80A, PureGro Co., West Sacramento, CA).
'Florida 683 K-strain' celery was transplanted 0.2 m apart in rows 0.6 m apart in
a muck soil in Belle Glade, FL. Treatments were arranged in a randomized complete
block design with four replications. Each plot was two rows by 7.7 m long. Treatments
were applied on either three (14-day intervals) or six dates (7-day intervals) in No-
vember and December, 1994. Applications were made using a CO, backpack sprayer
equipped with three equally-spaced (0.3 m) hollow disk/cone nozzles (D5-45). The
sprayer delivered 467.3 liter per ha at 2.7 kg/cm2. Numbers ofS. exigua and T. ni lar-
vae were recorded on five randomly selected plants per replicate on seven dates. Mar-
ketability was determined by harvesting the center 3.0 m from each row and
recording the weight, size, and number of marketable celery stalks.


December, 1997

















Jansson et al.: Novel Formulation for Emamectin Benzoate 429

Two rows of 'California Wonder' bell pepper were transplanted into beds (1.2 m
wide between centers) covered with plastic mulch in a light sandy soil in Immokalee,
FL. Plants were spaced 0.3 m apart within rows 0.6 m apart. Treatments were ar-
ranged in a randomized complete block design with four replications. Each plot was
one bed by 6.2 m long. Treatments were applied on either three (14-day intervals) or
six dates (7-day intervals) between December, 1994 and January, 1995 using a CO,
backpack sprayer system described previously. Numbers of southern armyworm, S.
eridania (Cramer), larvae were recorded on six randomly selected plants per replicate
on two dates. Percentage marketability was determined by harvesting the center 20
plants from each plot, and then dividing the number of marketable fruit by the total
number of fruit per plot.
Four rows of'Monument' cabbage were transplanted into 1.2 m beds in a sandy soil
in Loxahatchee, FL. Plants were spaced 0.2 m apart within rows 0.3 m apart. Treat-
ments were arranged in a randomized complete block design with four replications.
Each plot was one bed by 4.7 m long. Treatments were applied on either three (14-day
intervals) or six dates (7-day intervals) between December, 1994 and January, 1995
using a CO, backpack sprayer system described previously. Numbers of diamondback
moth, Plutella xylostella (L.), larvae were recorded on five randomly selected plants
per replicate on three dates. Damage ratings were recorded on five dates using a scale
from 1 to 5 modified from Greene et al. (1969) where 1 = no damage and 5 = damage
comparable to the nontreated control. Percentage marketability (damage rating < 2)
was determined based on the center 20 plants from each plot and evaluating each
plant for unacceptable damage to the head.
In the fourth trial, transplants of'Monument' cabbage were planted into two rows
per bed (0.9 m) in Loxahatchee, FL in March, 1995. Plants were spaced 0.2 m apart
in rows 0.3 m apart. Treatments were arranged in a randomized complete block de-
sign with four replications. Each plot was two beds wide by 7.7 m long. Treatments
were applied on four dates (7-day intervals) between April and May using the CO,
backpack sprayer system described previously. Numbers of P. xylostella larvae were
recorded on five randomly selected plants per replicate on five dates. Damage ratings
and percentage marketability were not recorded because ambient temperatures in-
creased considerably at the end of the trial thereby reducing head formation.

Data Analysis

Data were analyzed using both nonparametric methods (Conover 1980) and least
squares analysis of variance techniques (Zar 1984). Chemical availability of emamec-
tin benzoate was compared among formulations by chi-square analysis (Conover
1980). Percentage mortality was transformed to the arcsine of the square root to nor-
malize error variance. Means were separated by the Waller-Duncan K-ratio t-test
(WDKR, Waller & Duncan 1969). Percentage data from field experiments were also
transformed to the arcsine of the square root; all data from field studies were analyzed
using standard analysis of variance techniques. Means were separated by Duncan's
new multiple range test (P = 0.05) (SAS Institute 1990).

RESULTS AND DISCUSSION

Percentage Availability of Emamectin Benzoate

Percentages of ai (emamectin benzoate) that completely dissolved into water after
one hour and were then available for delivery differed (X = 30.2; P < 0.001) among the

















Florida Entomologist 80(4)


formulations tested. Most of the variation was attributable to a single formulation
(81). The percentage of emamectin benzoate that was available in solution was con-
siderably lower for formulation 81 (2WP; 47%) compared with all other formulations
tested (> 95%) (Table 1).

Glasshouse Tests

In the first trial, all of the formulations tested were very effective and comparable
(K-ratio = 100; WDKR) at killing both Lepidopteran targets when applied at the high
rate (8.4 g ai/ha) on all dates (Tables 2 and 3). High levels of mortality (96-100%) were
achieved up to 17 DAA for all formulations.
At the low rate (0.084 g ai/ha), differences in mortality ofS. exigua larvae did not
differ among formulations on most dates, although mortality achieved with formula-
tion 83 was significantly lower than that produced by formulation 81 and 49 on 14 and
17 DAA (Table 2). Mortality ofH. virescens did not differ among most formulations on
most dates, albeit trends in the data suggested that the EC (49) was the least effective
at controlling H. virescens at the low rate (0.084 g ai/ha) (Table 3).
In the second trial, the effectiveness of all four formulations at controlling both
Lepidoptera was comparable at both rates applied (Tables 4 and 5). Despite high con-
trol mortality on certain dates, no differences in larval mortality were observed, even
on dates when control mortality was acceptable (< 20%). In the miniature volume as-
say, mortality of S. exigua larvae on pepper and H. virescens larvae on chickpea did
not differ among formulations on all dates at the high concentration (20 ng/ml) (Table
6). On clipped leaves of scarlet runner bean, formulations were comparable in their ef-
fectiveness at killing S. exigua on days 0 and 3 after application; however, on 7 DAA,
formulation 83 was superior to formulation 81. All other formulations were compara-
ble in their effectiveness at killing S. exigua. Formulations differed markedly when
applied at the lower concentration (4 ng/ml) (Table 6). On pepper, most formulations
did not differ on all three dates; formulation 81 was the least effective formulation on
pepper. Formulations 83 and 49 were consistently the most effective formulations at
controlling H. virescens on chickpea. None of the formulations was effective at control-
ling S. exigua on 3 and 7 DAA on scarlet runner bean when applied at 4 ng/ml. On day
0, mortality of S. exigua on plants treated with formulations 85 and 49 was higher
than on those treated with formulations 81 and 83.
Mortality of S. exigua on scarlet runner bean was markedly lower than that ob-
served on pepper at both concentrations of each formulation tested. We recognize that
several factors (i.e., leaf structure, cuticle thickness, etc.) may account for these dif-
ferences; however, excision of scarlet runner leaves may have reduced translaminar
movement of emamectin benzoate into parenchyma tissue thereby affecting the res-
ervoir of the toxicant inside foliage over time. Translaminar movement of avermectin
insecticides is central to the prolonged residual efficacy observed in a variety of crops
under glasshouse and field conditions (Jansson & Dybas 1997).
In the third trial, all formulations were comparable at controlling S. exigua on sug-
arbeet and H. virescens on chickpea when applied at the high rate (Tables 7 and 8). Ef-
fectiveness at controlling T. ni on cabbage differed among formulations, even at the
high rate (Table 9). The EC formulation was consistently more effective at controlling
T. ni than formulations 86 and 88 on days 7 to 14 after application. Formulations 85
and 87 were comparable to the EC on most dates; formulations 86 and 88 were con-
sistently the least effective at controlling T. ni.
At the low rate, formulation 88 was consistently more effective at controlling S. ex-
igua than most other experimental formulations, but did not differ from control
achieved with the EC formulation on any evaluation date (Table 7). Formulations 85


December, 1997


















Jansson et al.: Novel Formulation for Emamectin Benzoate 431


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and 87 were consistently the least effective at controlling this insect when applied at
the low rate. All formulations were comparable in their effectiveness at controlling H.
virescens at the low rate (Table 8). Effectiveness at controlling T. ni differed among
formulations on day 0 after application (Table 9). The EC formulation was superior to
formulations 85, 86, and 87 when applied at the low rate; formulation 88 was compa-
rable to the EC on this date. The effectiveness of formulations at controlling T. ni did
not differ on all remaining evaluation dates.


Field Trials

All of the field trials demonstrated that solid formulations of emamectin benzoate
were as effective as the EC formulation at controlling Lepidoptera and reducing dam-
age on vegetable crops (Table 10). In the first cabbage trial, mean numbers ofP. xylos-
tella larvae did not differ (P < 0.05) among formulations applied at either 7- or 14-day
intervals on all dates, albeit only data for the peak population counts (7 days after the
fifth application [7DAA5]) are shown (Table 10). No larvae were found per 5 plants in
plots treated with all of the formulations of emamectin benzoate, whereas high larval
pressure was observed on nontreated plants (146.5 larvae/5 plants). Similar results
were found at harvest. Damage ratings did not differ among formulations (data not
shown); all formulations resulted in 100% marketability of heads, whereas only 2.5%
of heads were marketable in nontreated plots.
Similar results were found in the celery trial on all dates (although all data are not
shown). All formulations were comparable at controlling lepidopterous pests and re-
sulted in between 98 and 100% marketability of the crop (Table 10). On pepper, mean
numbers of S. eridania larvae did not differ among formulations on all evaluation
dates, albeit only two evaluation dates are shown (Table 10). Percentages of market-
able fruit did not differ (P < 0.05) among most formulations; however, plants that were
treated with formulation 81 at 7-day intervals and with formulation 83 at 14-day in-
tervals produced lower percentages of marketable fruit (86.3%) than those treated
with the EC formulation (49) at 7-day intervals (98.8%) (Table 10). All other formula-
tions produced similar percentages of marketable fruit (88.8-95.0%).
The lower (although not consistently significant) efficacy of formulation 81 at con-
trolling lepidopterous pests (as noted on pepper) concurs with an earlier report (Jan-
sson et al. 1996), and is presumably due to the lower percentage availability of the
active ingredient in solution. This formulation, however, was included in the present
tests because it served as a lead solid formulation with a novel composition. Formu-
lation 85 was subsequently designed from formulation 81, and as the data show, was
as effective as the EC formulation in all of the tests conducted. The improved effec-
tiveness of formulation 85, compared with formulation 81, was probably due, in part,
to its higher percentage of available ai in solution.
The fourth field trial was conducted to determine the effects of slight differences in
the composition of 5 SG formulations on field performance. All four of the formula-
tions were comparable to the EC formulation at controlling Lepidoptera on cabbage in
the field (Table 11).
As found in an earlier study (Jansson et al. 1996), excellent efficacy of all formula-
tions of emamectin benzoate was found for up to 14-17 days after application when ap-
plied at a rate as low as 0.084 g ai/ha under glasshouse conditions. Similar results
would not be expected in the field because avermectins are very susceptible to photo-
degradation. MacConnell et al. (1989) showed that the half-life of abamectin was < 10
h in light; the half-life for foliar dislodgeable residues of emamectin benzoate on celery
was approximately 15 h (Merck, unpublished data).






















Florida Entomologist 80(4)



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December, 1997


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Jansson et al.: Novel Formulation for Emamectin Benzoate 441

TABLE 11. MEAN (SEM) NUMBERS OF P. XYLOSTELLA LARVAE PER FIVE PLANTS ON
CABBAGE TREATED WITH DIFFERENT FORMULATIONS OF EMAMECTIN BEN-
ZOATE (MK-0244).

Spray Mean no. DBMV5 plants2
Rate, interval,
Formulation treatment g ai/ha days 7 DAA31 7 DAA32 7 DAA33 7 DAA34

MK-0244-085 5 SG 8.4 7 2.0b 2.3b 4.5b 1.3b
MK-0244-086 5 SG 8.4 7 13.0b 2.8b 0.8b 1.0b
MK-0244-087 5 SG 8.4 7 5.0b 1.8b 3.0b 1.0b
MK-0244-088 5 SG 8.4 7 4.0b 1.5b 2.3b 1.0b
MK-0244-049 0.16 EC 8.4 7 2.5b 1.3b 0.3b 0.0b
Nontreated check 31.0a 23.0a 16.8a 32.0a

DBM, diamondback moth.
Means within the same column followed by the same letter are not significantly different by Fisher's pro-
tected LSD (P < 0.05) (Zar 1984).
'As in Table 10.


The composition of pesticide formulations can affect their acute toxicity and safety
to mammals (Hudson & Tarwater 1988). The acute oral toxicity of technical grade em-
amectin benzoate is about 70 mg/kg (rat) in an ingestion assay (Anomymous 1995).
The acute oral LD50 of the 0.16 EC and 5 SG formulations are 2,646 and 1,516 mg/kg
body weight (rat), respectively (Anonymous 1995, Merck, unpublished data). The 5
SG formulation is more toxic than the EC formulation because it is 2.5-fold more con-
centrated. However, other safety features (ocular and skin irritation in rabbit) are
greatly improved with the 5 SG formulation compared with the 0.16 EC formulation
(Anonymous 1995). These improvements in safety have reduced the potential risks of
exposure during mixing and loading of the product into spray equipment and have im-
proved its FIFRA classification from category 1 (DANGER) to category 3 (CAUTION).
In addition to lowering risks of exposure, the 5 SG has additional attributes, including
elimination of volatile organic solvents as a part of the composition of the formulation;
its compatibility with water-soluble packaging to further reduce risks of exposure;
and potentially reducing the need for plastic packaging thereby reducing the environ-
mental burden.
These studies concurred with an earlier study that demonstrated that solid formu-
lations of the benzoate salt of emamectin were effective at controlling lepidopterous
pests on vegetable crops in the glasshouse and in the field (Jansson et al. 1996). More
importantly, they helped to identify a 5 SG formulation with a delivery system that is
novel for both avermectin chemistry as well as for the agrichemical industry (Merck,
unpublished). The 5 SG formulation has been developed along with the 0.16 EC for-
mulation for control of lepidopterous pests on a variety of vegetable crops and will
soon be available commercially. Because of its compatibility with integrated pest
management programs (Jansson & Dybas 1997), the new formulation of emamectin
benzoate should be an important tool for control of lepidopterous pests in the future.


ACKNOWLEDGMENTS

We thank G. Misich, L. Limpel, M. Poling (Ricerca, Inc., Painesville, OH), M. Alva-
rez (Merck & Co., Inc., Three Bridges, NJ), and D. Remick (Entocon, Inc.) for technical

















Florida Entomologist 80(4)


assistance. We thank L. D. Payne, C. L. Lanning, D. L. Cox, D. Rugg, and S. Branchick
for critically reviewing the manuscript. This is Merck Research Laboratories Publica-
tion No. 97-MS-0118.

REFERENCES CITED

ANONYMOUS. 1995. Technical data sheet, emamectin benzoate insecticide. Merck Re-
search Laboratories, Merck & Co., Inc., Three Bridges, NJ. 11 p.
CAMPBELL, W. C., R. W. BURG, M. H. FISHER, AND R. A. DYBAS. 1984. The discovery
of ivermectin and other avermectins, pp. 5-20. in P. S. Magee, G. K. Kohn & J.
J. Menn [eds.]. Pesticide synthesis through rational approaches. ACS Symp.
Ser. No. 255. American Chemical Soc., Washington, DC.
CONOVER, W. J. 1980. Practical nonparametric statistics, 2nd ed. J. Wiley, New York.
DYBAS, R. A. 1989. Abamectin use in crop protection, pp. 287-310. in W. C. Campbell
[ed.]. Ivermectin and abamectin. Springer-Verlag, New York.
DYBAS, R. A., N. J. HILTON, J. R. BABU, F. A. PREISER, AND G. J. DOLCE. 1989. Novel
second-generation avermectin insecticides and miticides for crop protection,
pp. 203-212. in A. L. Demain, G. A. Somkuti, J. C. Hunter-Cevera & H. W. Ross-
moore [eds.]. Novel microbial products for medicine and agriculture. Elsevier,
Amsterdam, Netherlands.
EDWARDS, M. H., S. A. KOLMES, AND T. J. DENNEHY. 1994. Can pesticide formulations
significantly influence pest behavior?: the case ofTetranychus urticae and dico-
fol. Entomol. Exp. Appl. 72: 245-253.
GREENE, G. L., W. G. GENUNG, R. B. WORKMAN, AND E. G. KELSHEIMER 1969. Cab-
bage looper control in Florida a cooperative program. J. Econ. Entomol. 62:
798-800.
HARTLEY, G. S., AND I. J. GRAHAM-BRYCE. 1980. Physical principles of pesticide be-
haviour: the dynamics of applied pesticides in the local environment in relation
to biological response. Vol. 1 and 2. Academic Press, London.
HUDSON, J. L., AND O. R. TARWATER 1988. Reduction of pesticide toxicity by choices
of formulation., p. 124-130. in B. Cross & H. Scher [eds.]. Pesticide formula-
tions. ACS Symp. Ser. No. 371, American Chemical Soc., Washington, DC.
JANSSON, R. K., AND R. A. DYBAS. 1997. Avermectins: biochemical mode of action, bi-
ological activity, and agricultural importance. in I. Ishaaya [ed.], Insecticides
with novel modes of action: mechanism and application. Springer-Verlag, New
York, (in press).
JANSSON, R. K., AND S. H. LECRONE. 1992. Efficacy of nonconventional insecticides for
control of diamondback moth, Plutella xylostella (L.), in 1991. Proc. Florida
State Hort. Soc. 104: 279-284.
JANSSON, R. K., W. R. HALLIDAY, AND J. A. ARGENTINE. 1998. Evaluation of miniature
and high volume bioassays for screening insecticides. J. Econ. Entomol. (in
press).
JANSSON, R. K., R. F. PETERSON, W. R. HALLIDAY, P. K. MOOKERJEE, AND R. A. DYBAS.
1996. Efficacy of solid formulations of emamectin benzoate at controlling lepi-
dopterous pests. Florida Entomol. 79: 434-449.
JANSSON, R. K., R. BROWN, B. CARTWRIGHT, D. Cox, D. M. DUNBAR, R. A. DYBAS, C.
ECKEL, J. A. LASOTA, P. K. MOOKERJEE, J. A. NORTON, R. F. PETERSON, V. R.
STARNER, AND S. WHITE. 1997. Emamectin benzoate: a novel avermectin deriv-
ative for control of lepidopterous pests. in A. Sivapragasam [ed.], Proceedings
of the 3rd International Workshop on Management of Diamondback Moth and
Other Crucifer Pests. MARDI, Kuala Lumpur, Malaysia.
LASOTA, J. A., AND R. A. DYBAS. 1991. Avermectins, a novel class of compounds: im-
plications for use in arthropod pest control. Annu. Rev. Entomol. 36: 91-117.
LEIBEE, G. L., R. K. JANSSON, G. NUESSLY, AND J. L. TAYLOR 1995. Efficacy of ema-
mectin benzoate and Bacillus thuringiensis at controlling diamondback moth
(Lepidoptera: Plutellidae) populations on cabbage in Florida. Florida Entomol.
78: 82-96.


December, 1997

















Jansson et al.: Novel Formulation for Emamectin Benzoate 443

MACCONNELL, J. G., R. J. DEMCHAK, F. A. PREISER, AND R. A. DYBAS. 1989. Relative
stability, toxicity, and penetrability of abamectin and its 8,9-oxide. J. Agric.
Food Chem. 37: 1498-1501.
SAS INSTITUTE. 1990. User's guide: statistics. Ver. 6. 4th ed. SAS Institute Inc., Cary,
NC.
WALLER, R. A., AND D. B. DUNCAN. 1969. A Bayes rule for the symmetric multiple
comparisons problem. J. Amer. Statist. Assn. 64: 1484-1503.
ZAR, J. H. 1984. Biostatistical analysis. Prentice-Hall, Englewood Cliffs, NJ.
















Doud et al.: Immatures of Pygospina spinata


DESCRIPTIONS OF NYMPHS OF THE CAT-TAIL FEEDING
DELPHACID PLANTHOPPER PYGOSPINA SPINATA
(HOMOPTERA: FULGOROIDEA)

CARL W. DOUD', STEPHEN W. WILSON1, AND JAMES H. TSAI2
'Department of Biology, Central Missouri State University
Warrensburg, Missouri 64093

'Fort Lauderdale Research and Education Center, University of Florida, IFAS
Fort Lauderdale, Florida 33314

ABSTRACT

Adult male and female genitalia and the first through fifth instar nymphs of the
delphacid planthopper Pygospina spinata Caldwell, collected from southern cattail
ipt.'. domingensis (Pers.) Steudel) in south Florida are described and illustrated
and a key to instars is provided. Nymphal instars are distinguished by differences in
body size and proportions, spination of the metatibiae, metatibial spurs, and metatar-
someres, and by the number of metatarsomeres.

Key Words: Insecta, Homoptera, Delphacidae, Pygospina spinata, immature stages,
Typha

RESUME

Se hacen descripciones del primer y quinto instar ninfal y del aparto reproductor
de hembras y machos del salta plants Pygospina spinata Caldwell, colectado de la
enea del sur 'I "."' domingensis (Pers.) Steudel) en el sur de Florida. Se publican
ilustraciones y una clave para identificaci6n de la especie. Los instares ninfales se dis-
tinguen por ciertas diferencias en el tamaio y proporciones del cuerpo, en las espinas
de la metatibia, las espuelas de la metatibia y metatarsomeros y por el numero de me-
tatarsomeros.


The Neotropical delphacid genus Pygospina includes five species, P. aurantii
(Crawford), P. reducta Caldwell, P. rezendensis (Muir), P. spinata Caldwell, and P.

















Florida Entomologist 80(4)


spinigera (Fennah) (Caldwell & Martorell 1951). No information on biology or imma-
tures of any of these species is available. While collecting in southern Florida, we
(SWW & JHT) found adults and nymphs of P. spinata at the bases of leaves in the in-
ner whorls of southern cattail i'I -'., domingensis (Pers.) Steudel; Typhaceae). Py-
gospina spinata was described from two specimens from Puerto Rico (Caldwell &
Martorell 1951); one specimen has been collected in a Florida light trap (Frost 1964)
and two specimens were found from Cocos Island (unpublished data). The apparent
rarity of this species is probably due to its feeding habit. We were only able to collect
specimens by stripping the leaves from about ten cattails where 104 orange nymphs
and four adults were found.
Pygospina spinata is the only New World delphacid recorded from cattails; four
other delphacid species have been recorded from cattails in Europe and Asia.
Changeondelphax velitchkovski (Melichar) has been recorded from T laxmannii Lep-
echin in South Korea (Kwon 1982); ChlIoi,ro totYryonono Matsumura has been found
on Phragmites australis (Cav.) Trin. (Poaceae) in Asia (Yang 1989) and T laxmannii
in eastern Russia (Vilbaste 1968); Kakuna sapporonis (Matsumura) has been re-
corded from T laxmanni in eastern Russia (Vilbaste 1968), and Matutinus putoni (A.
Costa) feeds on T latifolia L. and T angustifolia L. in Europe (D'Urso & Guglielmino
1986).


MATERIALS AND METHODS

Specimens used for description have the following collecting data: Florida: Bro-
ward Co., 175 12 miles north of 1595, 31-V-1994, ex. Typha domingensis, coll. S. Wilson
and J. Tsai (2 males, 2 females, 27 first instars, 17 second instars, 15 third instars, 23
fourth instars, 22 fifth instars). Specimens are housed in S. W. Wilson's planthopper
collection at Central Missouri State University, Warrensburg.
The fifth instar is described in detail but only major differences are described for
fourth through first instars. Arrangement and number of pits is provided for the fifth
and fourth instars; this information is not given for earlier instars because the pits
are extremely difficult to discern (those that could be observed relatively easily are il-
lustrated). Measurements are given in mm as mean SD. Length was measured from
apex of vertex to apex of abdomen, width across the widest part of the body, and tho-
racic length along the midline from the anterior margin of the pronotum to the poste-
rior margin of the metanotum.

DESCRIPTIONS

Adult. A lateral view of an adult and a somewhat diagrammatic illustration of the
male genitalia were provided by Caldwell & Martorell (1951).
Male genitalia (Fig. 1A, B, C). Pygofer, in lateral view, triangular, with an acute
lateral process on laterocaudal aspect on either side, and an elongate blunt process on
ventrocaudal aspect; diaphragm below aedeagus v-shaped, unarmed. Anal tube, in
lateral view, with a single spinose process originating on the ventrocaudal aspect of
the tube. Styles, in caudal view, broadest across basal third, narrowing distally to a
bulbous apex. Aedeagus subcylindrical, with an acute dorsocaudally directed process
in basal third, and a postapical flange extending laterally on right (Fig. 1B).
Female genitalia (Fig. 2A, B, C). The terminology used in describing the female
genitalia follows Asche (1985) and Heady & Wilson (1990). Tergite nine oriented an-
teroventrally (see Asche 1985), elongate, longitudinally concave in ventral midline.
Anal tube subcylindrical. Genital scale very large, subovate. Valvifers of segment


December, 1997















Doud et al.: Immatures of Pygospina spinata


C


Fig. 1. P. spinata male genitalia. (A) Pygofer, anal tube, and style, lateral view. (B)
Lateral view of aedeagus and ventral view of apex of aedeagus. (C) Pygofer, anal tube,
and styles, caudal view. Bar = 0.5 mm.


eight each covering approximately one-fourth of tergite nine anterolaterally; slender,
broadly concave on median margin. Lateral gonapophyses of segment nine elongate,
spatulate posteriorly. In lateral view, median gonapophyses of segment nine saber-
shaped, with approximately 25 prominent small teeth on dorsal margin in distal one-
half. Gonapophyses of segment eight adhering tightly to median gonopophyses of seg-
ment nine; slender, acute apically.
Fifth Instar (Figs. 3A, B). Length 2.4 0.2 mm; thoracic length 0.9 0.06 mm; tho-
racic width 1.04 0.08 mm; N = 13. Body straw colored with white middorsal line ex-
tending from vertex almost to end of abdomen. Form elongate, subcylindrical slightly
flattened dorsoventrally. Vertex subtriangular; narrowing anteriorly with two pairs of
longitudinal carinae which extend onto frons. Frons border with clypeus slightly con-
cave; lateral margin strongly convex and carinate (outer carinae) and paralleled by
second pair of carinae (inner carinae) continuous with lateral margins of vertex; area
between inner and outer carinae with nine pits on each side (six visible in ventral
view, three in dorsal aspect); four pits between each outer carina and eye. Clypeus
narrowing distally, consisting of subconical basal postclypeus and cylindrical distal
anteclypeus. Beak three-segmented, cylindrical, segment one hidden by anteclypeus,
segment two subequal in length to segment three, with black apex. Antennae three-
segmented; scape short, cylindrical; pedicel subcylindrical, 2x length of scape, with
















Florida Entomologist 80(4)


Fig. 2. P. spinata female genitalia. (A) Ventral view. (B) Lateral view. (C) Lateral
view of ovipositor (median gonapophyses of segment 9). Bar = 0.5 mm.

about ten small pits, four pits visible in dorsal aspect; flagellum bulbous basally, with
elongate bristle-like extension distally, bulbous base approximately 0.2x length of


December, 1997

















Doud et al.: Immatures of Pygospina spinata


Fig. 3. P. spinata fifth instar nymph. (A) Habitus, dorsal view. (B) Frontal view of
head. Bar = 0.5 mm.


pedicel. Eyes black; in dorsal aspect, median border red. Thoracic nota divided by mid-
dorsal line into three pairs of plates. Pronotal plates subtriangular (in dorsal view);
anterior margin convex; posterior border sinuate; each plate with a weak posterolat-
erally directed carina and seven pits extending anteriorly from near middorsal line
posterolaterally to lateral margin (lateralmost pits often not visible in dorsal view).
Mesonotum with median length 1.5x that of pronotum; elongate lobate wingpads ex-
tending to tips of metanotal wingpads; each plate with very weak posterolaterally di-
rected carina originating on anterior margin in median one quarter and terminating
on posterior margin in lateral one third, triangular area between carinae elevated;
two pits near middle of plate on either side of carinae and two pits on lateral one half
of plate. Metanotum with median length slightly shorter than that of mesonotum,
subtriangular; lobate wingpads extending to third tergite; each plate with one pit
near middle. Pro- and mesocoxae elongated and directed posteromedially; metacoxae
fused to sternum. Metatrochanter short and subcylindrical. Metatibia with two
spines on lateral aspect of shaft, an apical transverse row of five black-tipped spines
on plantar surface and a subtriangular flattened movable spur with one apical tooth
and 15-19 other teeth on posterior aspect. Pro- and mesotarsi with two tarsomeres,
tarsomere one wedge-shaped; tarsomere two subconical, with pair of apical claws and
median membranous pulvillus. Metatarsi with three tarsomeres; tarsomere one with
















Florida Entomologist 80(4)


Fig. 4. P. spinata first through fourth instar nymphs. (A) First instar. (B) Second
instar. (C) Third instar. (D) Fourth instar. Bar = 0.5 mm.


apical transverse row of seven black tipped spines; tarsomere two cylindrical, approx-
imately 0.3x length of tarsomere one, with apical transverse row of four black tipped
spines on plantar surface; tarsomere three subconical, slightly longer than tarsomere
two, with pair of apical claws and median pulvillus. Abdomen nine segmented; flat-
tened dorsoventrally; widest across fourth abdominal segment. Tergite one small,
subtriangular; tergite two subtriangular approximately 1.3x width of first; tergites
three through eight subrectangular, four with one pit on both lateral margins, five
with two lateral margin pits on each side, six through eight each with three pits on
each side; segment nine surrounding anus, with three pits on each side; female with
one pair of acute processes extending from juncture of sternites eight and nine; males
lacking processes.
Fourth Instar (Fig. 4D) Length 1.8 0.09 mm; thoracic length 0.7 0.02 mm; tho-
racic width 0.8 0.03 mm; N = 15. Antennal flagellum with basal portion approxi-
mately 0.3x length of pedicel, about seven small pits. Mesonotal wingpads shorter,
each covering approximately two-thirds of metanotal wingpad laterally. Metanotal
median length 1.5x that of mesonotum; wingpad extending to tergite three. Metatibial
spur smaller, with one apical tooth and seven to eight marginal teeth. Metatarsi with


December, 1997

















Doud et al.: Immatures of Pygospina spinata


two tarsomeres; metatarsomere one with apical transverse row of six black-tipped
spines; metatarsomere two with three black-tipped spines in middle of tarsomere.
Third Instar (Fig. 4C). Length 1.4 0.1 mm; thoracic length 0.5 0.02 mm; tho-
racic width 0.6 0.03 mm; N = 15. Mesonotal wingpads shorter, each covering one-
third of metanotal wingpad laterally. Metanotal wingpads extending to tergite two.
Metatibial spur smaller, with one apical tooth and one to three marginal teeth. Meta-
tarsomere one with apical transverse row of five black-tipped spines on plantar sur-
face.
Second Instar (Fig. 4B). Length 1.3 + 0.1 mm; thoracic length 0.4 0.02 mm; tho-
racic width 0.4 + .02 mm; N = 14. Wingpads undeveloped. Metatibia with apical row
of three black-tipped spines; spur small with one apical tooth and no marginal teeth,
approximately 3x longer than longest metatibial spine. Metatarsomere one with four
apical black-tipped spines.
First Instar (Fig. 4A). Length 1.07 0.05 mm; thoracic length 0.3 0.02 mm; tho-
racic width 0.3 0.02 mm; N = 15. Bulbous base of antennal flagellum 0.7x length of
pedicel. Metatibia lacking lateral spines on shaft; metatibial spur smaller, approxi-
mately 1.5x length of longest metatibial spine.

KEY TO THE NYMPHAL INSTARS OF PYGOSPINA SPINATA

1. Metatibial spur with seven to nineteen marginal teeth (Fig. 5); mesonotal wing-
pads extending to half length of metanotal wingpads (Figs. 3A, 4D) .......... 2
Metatibial spur with fewer than seven marginal teeth (Fig. 5); mesonotal wing-
pads not extending beyond half length of metanotal wingpads (Figs. 4A, B, C) 3
2. Metatarsi with three tarsomeres; metatibial spur with more than ten marginal
teeth (Figs. 3A, 5) .......................................... 5th Instar
Metatarsi with two tarsomeres; metatibial spur with fewer than eight marginal
teeth (Figs. 4D, 5) .......................................... 4th Instar
























Fig. 5. P. spinata apices of metathoracic legs, plantar surface, of first (left) through
fifth (right) instar nymphs. Bar = 0.5 mm.

















Florida Entomologist 80(4)


3. Metatarsomere one with apical transverse row of five spines; spur with one to
three marginal teeth (Fig. 5) .................................. 3rd Instar
Metatarsomere one with apical transverse row of four spines; spur lacking mar-
ginal teeth (Fig. 5) .................................................. 4
4. Metatibia with three lateral spines on shaft and metatarsomere one with apical
transverse row of four spines; spur more than 3x length of longest apical spine
(Figs. 4B, 5) .............................................. 2nd Instar
Metatibia without lateral spines on shaft and apical transverse row of three
spines; spur about 1.5x length of longest apical spine (Figs. 4A, 5) ... 1st Instar

ACKNOWLEDGMENT

We thank Dr. David Sutton for identifying the host plant. Florida Agricultural Ex-
periment Stations Journal Series #R-05537.

REFERENCES CITED

ASCHE, M. 1985. Zur Phylogenie der Delphacidae Leach, 1815 (Homoptera Cicadina
Fulgoromorpha). Marburger Entomol. Publ. 2(1): 1-910.
CALDWELL, J. S., AND L. F. MARTORELL. 1951. Review of the auchenorynchous Ho-
moptera of Puerto Rico. Part II. The Fulgoroidea except Kinnaridae. J. Agric.
Univ. Puerto Rico 34: 133-269.
D'URSO, V., AND A. GUGLIELMINO. 1986. Sviluppo postembrionale diMatutinusputoni
(Costa, A., 1888) (Homoptera, Delphacidae) e note sulla sua biologia. Animalia
13(1/3): 77-93.
FROST, S. W. 1964. Insects taken in light traps at the Archbold Biological Station,
Highlands County, Florida. Florida Entomol. 47: 129-161.
HEADY, S. E., AND S. W. WILSON. 1990. The planthopper genus Prokelisia (Ho-
moptera: Delphacidae): Morphology of female genitalia and copulatory behav-
ior. J. Kansas Entomol. Soc. 63: 267-278.
KWON, Y. J. 1982. New and little known planthoppers of the Family Delphacidae (Ho-
moptera: Auchenorrhyncha). Korean J. Entomol. 12: 1-11.
VILBASTE, J. 1968. On the Cicadine fauna of the Primosk region. Tallin, 180 pp.
YANG, C. T. 1989. Delphacidae of Taiwan (II) (Homoptera: Fulgoroidea). Nat. Sci.
Council (Rep. China) Spec. Publ. 6: 1-334.


December, 1997
















Medal et al.: Three-cornered Alfalfa Hopper Predation 451

PREDATION OF SPISSISTILUS FESTINUS
(HOMOPTERA:MEMBRACIDAE) NYMPHS BY HEMIPTERAN
PREDATORS IN THE PRESENCE OF ALTERNATIVE PREY

J. C. MEDAL', A. J. MUELLER', T. J. KRING1 AND E. E. GBUR, JR2.
'University of Arkansas, Department of Entomology, Fayetteville, AR 72701

2University of Arkansas, Agricultural Statistics Laboratory, Fayetteville, AR 72701

ABSTRACT

The feeding preferences of Geocoris punctipes (Say) and Nabis roseipennis Reuter
were studied in the laboratory. Female adult predators were exposed for 24h to three
Spissistilus festinus (Say) nymphal densities and two Pseudoplusia includes
(Walker) larval densities. Feeding responses of the predators when exposed to second
and third S. festinus nymphal stages and second instar P. includes and/or Helicov-
erpa zea (Boddie) as a food choice also were studied. Predation of S. festinus nymphs
by G. punctipes and N. roseipennis did not differ significantly in the presence of P. in-
cludens and/or H. zea larvae as alternative prey. Geocoris punctipes and N. roseipen-
nis caused mortality of S. festinus nymphs of 33 to 83% and 33 to 100%, respectively,
even in the presence of the lepidopterous larvae.

Key Words: Three-cornered alfalfa hopper, Geocoris punctipes, Nabis roseipennis, bio-
logical control

RESUME

Las preferencias alimentarias de Geocoris punctipes (Say) y Nabis roseipennis
Reuter fueron estudiadas en el laboratorio. Las hembras predatoras adults fueron
expuestas durante 24 horas a tres densidades ninfales de Spissistilus festinus y a dos
densidades larvales de Pseudoplusia includes (Walker). Tambien fueron estudiadas
las respuestas alimentarias de los predatores cuando se expusieron a el segundo y ter-
cero estadios ninfales, y a P. includes y/o Helicoverpa zea, en el segundo estadio lar-
val. La predaci6n de ninfas de S. festinus por G. punctipes y N. roseipennis no mostr6
diferencias significativas cuando estaban presents larvas de P. includes y/o H. zea
como press alternatives. Geocoris punctipes y N. roseipennis causaron mortalidades
de ninfas de S. festinus del 33 al 83%, y del 33 al 100%, respectivamente, aun cuando
tenian como alternative alimentarse de las larvas lepidopteras.




Geocoris punctipes (Say) (Heteroptera: Lygaeidae) and Nabis roseipennis Reuter
(Heteroptera: Nabidae) are polyphagous predators commonly found in soybean, Gly-
cine max (L.), fields (Turnipseed 1974, Irwin and Shepard 1980). They feed on a diver-
sity of arthropod pests (Elvin et al. 1983, Crocker and Whitcomb 1980) including
nymphs of the three-cornered alfalfa hopper, Spissistilus festinus (Say) (Heteroptera:
Membracidae) (Spurgeon 1992). The rate of predation on a given prey may be influ-
enced by the presence of alternative prey (Ridgway and Jones 1968, Murdoch 1969,
Ables et al. 1978). Although generalist predators such as Geocoris spp. and Nabis spp.
attack a variety of prey, they may exhibit a preference for specific prey size or a prey
with limited or no defense. Crocker and Whitcomb (1980) found that the largest per-
centage (79%) of target prey captured by Geocoris spp. were those that remained pas-

















Florida Entomologist 80(4)


sive during physical contact with the predator. Geocoris spp. hunting behavior on
soybean plants includes both searching actively on all plant parts and remaining mo-
tionless waiting for prey (Crocker and Whitcomb 1980). Geocoris spp. attack by walk-
ing fast or running toward their prey with the beak extended straight forward and
quickly inserting the stylet to subdue the prey. This predator has been observed some-
times to lift the prey in the air with its beak while feeding.
Nabis roseipennis is larger and more aggressive than G. punctipes. Its hunting
strategy also involves active random movements searching for prey in the soybean
canopy and remaining motionless or 'waiting' for relatively long periods of time. This
predator has been observed using its legs to grasp prey.
Previous laboratory and field studies indicate that G. punctipes and N. roseipennis
feed on S. festinus nymphal stages (Medal et al. 1995). Geocorispunctipes has a pref-
erence for early (1st, 2nd) and intermediate (3rd) nymphal developmental stages,
while N. roseipennis feeds equally well on all S. festinus nymphal stages.
Laboratory studies were designed to determine the feeding response or change in
number of prey attacked by G. punctipes and N. roseipennis female adults as the S.
festinus nymph density increased, and how the presence of Pseudoplusia includes
(Walker) (Lepidoptera: Noctuidae) and Helicoverpa zea (Boddie) (Lepidoptera: Noctu-
idae) larvae as alternate prey affected predation on S. festinus.

MATERIALS AND METHODS

Feeding Responses at Different Prey Densities

Geocoris punctipes used in these studies were obtained from a laboratory colony es-
tablished from adults collected in southwestern Arkansas soybean, and alfalfa,Medi-
cago sativa L. fields during the spring and summer of 1992-3.Nabis roseipennis were
collected as immatures and reared in the laboratory to the adult stage onH. zea eggs
and green bean, Phaseolus vulgaris L. pods. The 1-3 week old female adult predators
were held with only bean pods for 24h before the experiment. Second and thirdS. fes-
tinus instars and second P. includes instars were obtained from a laboratory colony.
Spissistilus festinus were maintained on P. vulgaris pods and P. includes on artificial
diet (Burton 1969) at 26 1 C, 70 to 80% RH, and a photoperiod of 14:10 (L:D)h. The
studies were conducted in a growth chamber under similar environmental conditions.
Predator and prey were caged on individual potted soybean plants (CV: Bragg) in
growth stages V2-3. The cages were 2-liter clear plastic soda bottles with the tops and
bottoms removed. The top was covered with fine cloth to allow air movement. The base
of the cage in contact with the soil was sealed by placing tape around the bottom of the
cage and the upper rim of the pot.
Treatments were a predator species (single G. punctipes orN. roseipennis adult fe-
male), three S. festinus nymphal densities (3, 6, 9), and three P. includes larval den-
sities (0, 2, 4) which were arranged in a 3 x 3 factorial in a completely randomized
design with four replications for each predator. The two predator species with their re-
spective prey combinations were run as two separate experiments. Prey mortality was
recorded after 24h. Percent prey mortality data for each predator species were trans-
formed using arcsin/y and analyzed separately by an analysis of variance (SAS Insti-
tute 1988). Means were separated using a LSD procedure when appropriate.

Feeding Responses with P. includes and H. zea as Alternative Prey

One early or intermediate S. festinus nymphal stage was provided along with sec-
ond instar (1-week old) H. zea and/or P. includes larvae as alternative prey choices.


December, 1997

















Medal et al.: Three-cornered Alfalfa Hopper Predation 453

Source of predators and S. festinus was as previously described. These alternative
prey were chosen because these lepidopteran larvae are commonly found on soybean
plants when S. festinus nymphs are present.
The study was conducted in an environmental chamber under conditions previ-
ously described. Geocoris punctipes was exposed to second S. festinus nymphal stage,
and N. roseipennis was exposed to third nymphal stage. Treatments included one
starved, 1-3 week old female G. punctipes or N. roseipennis adult exposed for 24h to
each of the following four prey combinations: 1) one S. festinus second or third instar,
2) one each S. festinus (N2 or N3) + P. includes, 3) one each S. festinus (N2 or N3) +
H. zea, and 4) one each S. festinus (N2 or N3) + P. includes + H. zea. Prey (all combi-
nations) with no predator were included as controls. All treatments were arranged in
a completely randomized design with six replications. The two predator species with
their respective prey combinations were conducted as two separate experiments. Prey
mortality was recorded after 24h. Percent mortality data were analyzed by a 2-sample
binomial test for equal proportions (Ott 1984).

RESULTS AND DISCUSSION

Feeding Responses at Different Prey Densities

Spissistilus festinus nymphal density (P = 0.09), P. includes larval density (P =
0.72), and their interaction (P = 0.48) did not significantly affect the percent S. festi-
nus nymphal mortality due to G. punctipes. The data indicate that a near constant
percent prey mortality occurred regardless of the prey density (Table 1). Nonsignifi-
cance may be due to the relatively large variability in feeding among the individual
predators.
Spissistilus festinus nymphal density and P. includes larval density interaction
had a significant effect (P = 0.02) on percent S. festinus mortality when N. roseipennis
was the predator (Table 2). Analysis of percent P. includes mortality due to N.
roseipennis also indicated a significant interaction (P = 0.04). The percent S. festinus

TABLE 1. MEAN PERCENT MORTALITY* OF SPISSISTILUS FESTINUS NYMPHS AND
PSEUDOPLUSIA INCLUDES (P.I.) LARVAE WHEN EXPOSED SIMULTANEOUSLY
TO ADULT FEMALE GEOCORIS PUNCTIPES FOR 24H.

S. festinus Density
P.I.
Prey Density 3 6 9 Mean

0 50.0 50.0 50.0 50.0
2 75.0 29.2 33.3 45.8
S. festinus**
4 58.3 33.3 25.0 38.9

Mean 61.1 37.5 36.1 44.9

2 0.0 12.5 12.5 8.3
P. includess* 4 25.0 12.5 6.6 14.6
Mean 12.5 12.5 9.4 11.5

*Average of four replications. Analysis of variance was made using arcsin y transformed data.
**Spissistilus festinus density, R includes density, and their interaction were not significant (P = 0.05, F-
test).

















Florida Entomologist 80(4)


mortality due to N. roseipennis, when the predator did not have P. includes as an al-
ternative prey, did not differ significantly at the various S. festinus density levels (Ta-
ble 2).
Percent mortality of S. festinus nymphs due to N. roseipennis was not significantly
increased in the presence of P. includes larvae, but the percent S. festinus mortality
was significantly decreased with this predator only at the six S. festinus and four P. in-
cludens density combinations (Table 2). The number of P. includes larvae killed due
to N. roseipennis at the various S. festinus and P. includes density combinations
ranged from 1.5 to 3.0. These values are higher than those obtained with G. punctipes
which ranged from 0-1.
Nabis roseipennis and G. punctipes did not exhibit a preference for P. includes or
S. festinus. Nabis roseipennis fed on approximately the same number of total prey
when they consisted of both S. festinus nymphs and P. includes larvae. Murdoch
(1969), and Murdoch and Marks (1973) indicated that generalist predators tend to
concentrate their attack on the most abundant prey species, if it is an acceptable prey.
Increased feeding by either predator on either prey species was not exhibited at the
high prey densities although more frequent encounters between predators and prey
would be expected at high prey densities. This suggests that N. roseipennis and G.
punctipes do not have a strong preference for either of these prey and that they can
feed on both prey when they are present simultaneously.
These results obtained indicate that S. festinus is a potential prey of adult G. punc-
tipes and N. roseipennis, and that predator feeding responses were not generally af-
fected by the presence of one-week old P. includes larvae at the prey density levels
evaluated.

Feeding Responses with P. includes and H. zea as Alternative Prey

Mortality in control treatments (prey without predators) was extremely low (<
5%), so that correction was not necessary. The percent mortality of S. festinus nymphs
due to adult G. punctipes did not differ significantly (P = 0.05, binomial test) in the


TABLE 2. MEAN PERCENT MORTALITY OF SPISSISTILUS FESTINUS NYMPHS AND
PSEUDOPLUSIA INCLUDES (P.I.) LARVAE WHEN EXPOSED SIMULTANEOUSLY
TO ADULT FEMALE NABIS ROSEIPENNIS FOR 24H.

S. festinus Density
P.I.
Prey Density 3 6 9 Mean

0 33.3 abc 41.7 ab 47.2 ab 40.7
2 16.7 bc 45.8 ab 25.0 abc 29.2
S. festinus**
4 58.3 a 8.3 c 22.2 abc 29.6
Mean 36.1 31.9 31.5 33.2

2 75.0 ab 75.0 ab 100.0 a 83.8
P. includess* 4 75.0 ab 62.5 bc 37.5 c 58.3
Mean 75.0 68.7 68.7 70.8

*Average of four replications. Analysis of variance was made using arcsin y transformed data.
**Values within prey species followed by the same letter do not differ at the 0.05 probability level using LSD


December, 1997

















Medal et al.: Three-cornered Alfalfa Hopper Predation 455

TABLE 3. MEAN PERCENT MORTALITY* OF SPISSISTILUS FESTINUS (S.F.), PSEUDOPLU-
SIA INCLUDES (P.I.), AND HELICOVERPA ZEA (H.Z.) EXPOSED TO GEOCORIS
PUNCTIPES FOR 24H.

Treatment

S.F. + P.I. S.F. + H.Z. S.F. + P.I. + H.Z.

Prey S.F. S.F. P.I. S.F. H.Z. S.F. P.I. H.Z.

S. festinus 67a** 33a 67a 83a
P. includes 67a 50a
H. zea Ob Ob

*Average of six replications.
**Values followed by the same letter do not differ at the 0.05 probability level using 2-sample binomial test
for equal proportions.


presence of P. includes and/or H. zea larvae as alternative prey (Table 3). Spissistilus
festinus mortality ranged from 33 to 83%.
Comparison of the percent mortality of the two alternative prey species shows that
the P. includes mortality was significantly higher (P = 0.05, binomial test) than that
of H. zea (Table 3). Geocoris punctipes did not feed on H. zea larvae. A possible expla-
nation for this lack of feeding may be related to the defense of H. zea larvae when at-
tacked. When disturbed by a predator, H. zea swung its anterior or posterior end or
made quick lateral body movements to repel the predator. Observations made by
Crocker and Whitcomb (1980) on hunting behavior of Geocoris spp. under natural con-
ditions indicated that when prey are abundant, this predator tends to abandon prey
that resist capture.
Spissistilus festinus nymphal mortality by N. roseipennis was not significantly af-
fected (P = 0.05, binomial test) by the presence of P. includes and/or H. zea larvae
(Table 4). Nabis roseipennis showed a more generalist feeding response than G. punc-
tipes, consuming individuals of all three kinds of prey available. Nabis roseipennis


TABLE 4. MEAN PERCENT MORTALITY* OF SPISSISTILUS FESTINUS (S.F.), PSEUDOPLU-
SIA INCLUDES (P.I.), AND HELICOVERPA ZEA (H.Z.) EXPOSED TO NABIS
ROSEIPENNIS FOR 24H.

Treatment

S.F. + P.I. S.F. + H.Z. S.F. + P.I. + H.Z.

Prey S.F. S.F. P.I. S.F. H.Z. S.F. P.I. H.Z.

S. festinus 67ab** 50b 100a 33b
P. includes 100a 33b
H. zea 67ab 83ab

*Average of six replications.
**Values followed by the same letter do not differ at the 0.05 probability level using a 2-sample binomial test
for equal proportions.

















Florida Entomologist 80(4)


was able to overcome (9 out of 12 events) the H. zea defensive responses probably be-
cause of its larger size and its aggressive use of the front legs to grasp prey.
Geocoris punctipes and N. roseipennis caused mortality of S. festinus nymphs of 33
to 83%, and 33 to 100%, respectively, even in the presence of the caterpillars as a food
choice (Tables 3-4). Results indicate that predators such as G. punctipes and N.
roseipennis contribute to the reduction of S. festinus even in the presence of lepi-
dopterous larvae. Further biological studies on predator-prey interactions under field
conditions will provide basic information to develop predictive models on population
dynamics of crop pests and their natural enemies that can be used in pest manage-
ment programs.

ACKNOWLEDGMENTS

We thank D. T. Johnson, W. C. Yearian, and S. Y. Young (Department of Entomol-
ogy, University of Arkansas) for reviewing the manuscript. This research was sup-
ported in part by an Arkansas Soybean Promotion Board grant. Article published with
the approval of the Director, Arkansas Agricultural Experiment Station, University of
Arkansas, Fayetteville.

REFERENCES CITED

ABLES, J. R., S. L. JONES, AND D. W. MCCOMMAS. 1978. Response of selected predator
species to different densities ofAphisgossypii and Heliothis virescens eggs. En-
viron. Entomol. 7: 402-404.
BURTON, R. L. 1969. Mass rearing the corn earworm in the laboratory. USDA Agric.
Res. Serv., Serv., ARS-134.
CROCKER, K. 0., AND W. H. WHITCOMB. 1980. Feeding niches of the big-eyed bugs Geo-
coris bullatus, G. punctipes, and G. uliginosus (Hemiptera: Lygaeidae). Envi-
ron. Entomol. 9: 508-513.
ELVIN, M. K., J. L. STIMAC, AND W. H. WHITCOMB. 1983. Estimating rates of arthro-
pod predation on velvetbean caterpillar larvae in soybeans. Fla. Entomol. 66:
319-330.
IRWIN, M. E., AND M. SHEPARD. 1980. Sampling predaceous Hemiptera on soybean.
pp. 503-531 in M. Kogan and D. C. Herzog (eds.). Sampling methods in soybean
entomology. Springer-Verlag, New York. 587 pp.
MEDAL, J. C., A. J. MUELLER, T. J. KRING, AND E. E. GBUR, JR. 1995. Developmental
stages of Spissistilus festinus (Homoptera: Membracidae) most susceptible to
hemipteran predators. Fla. Entomol. 78: 561-564.
MURDOCH, W. W. 1969. Switching in general predators: experiments on predator
specificity and stability of prey populations. Ecological Monogr. 39: 335-354.
MURDOCH, W. W., AND J. R. MARKS. 1973. Predation by coccinellid beetles: experi-
ments on switching. Ecology 54: 160-167.
OTT, L. 1984. An introduction to statistical methods and data analysis. Duxbury
Press. Boston. 775 p.
RIDGWAY, R. L., AND S. L. JONES. 1968. Plant feeding by Geocoris pallens and Nabis
americoferus. Ann. Entomol. Soc. Am. 61: 232-233.
SAS INSTITUTE. 1988. SAS procedures guide, release 6.03 ed. SAS Institute. Cary,
N.C.
SPURGEON, D. W. 1992. Three-cornered alfalfa hopper (Homoptera: Membracidae) on
soybean: Insect-plant interactions. Ph.D. dissertation, University of Arkansas,
Fayetteville.
TURNIPSEED, S. G. 1974. Sampling soybean insects by various D-Vac, sweep and
ground cloth methods. Fla. Entomol. 57: 219-223.


December, 1997

















Li & Christiansen: New Homidia from China


A NEW SPECIES OF HOMIDIA FROM CHINA (COLLEMBOLA:
ENTOMOBRYIDAE)

LIU-RU LI1 AND KENNETH A. CHRISTIANSEN2
'Department of Biology, Nanjing University, Nanjing 210093, P.R. China

'Grinnell College, Grinnell, IA 50112 USA

ABSTRACT

A new species of Entomobryidae, Homidia pentachaeta, is described from China.
It is unique in the presence of 5 lateral macrochaetae on each side of abdominal seg-
ment 3.

Key Words: Collembola, Entomobryidae, Homidia pentachaeta, new species, China

RESUME

Una nueva especie de Entomobryidae, Homidia pentachaeta, es descrita de China.
La especie es unica por la presencia de 5 macrochetae en cada lado del tercer seg-
mento abdominal.




Many species of the genus Homidia Btrner have been described from Japan and
Korea but only five species have so far been described from China: the widespread Ho-
midia socia Denis, H. nigrocephala Uchida, H. sinensis Denis, n. status, H. transitoria
Denis, and a species from Tibet currently in press. A sixth species is described here.

Homidia pentachaeta sp. nov. (Figs. 1- 15).

Maximum body length 3.0 mm. Pattern as in Figs. 1, 4: background color white to
pale purplish; Ant. III & IV pale purple; eye patches dark blue; interantennal patch
dark, small, and nearly triangular; Th. III with a pair of irregular slightly darker
patches near midline; Abd. III with a wide, slightly darker, band on the central part
of dorsum; other segments with unevenly scattered pigment.
Antenna 2.9 3.5 times as long as head. Mean ratios of antennal segments 1-4: 1.0/
1.2/1.0/1.8. Ant. IV with 2 apical bulbs (Fig. 6). Dorsal chaetotaxy of head (after Szep-
tycki, 1973): 4-6 antennal (A), 3 ocellar (0), 6 sutural (S) macrochaetae on frontal
area. Eyes 8+8, G and H much smaller than others and masked by dark pigment (Fig.
3). Labrum without papillae, seta a2 shorter than a', but longer than b' (Fig. 7). Setal
formula of labial base as M, R, E, L', L2; setae E & L' smooth, others ciliate (Fig. 8).
In this paper we follow the groupings of the body macrochaetae developed in the
work on Sinella s.s. by Chen & Christiansen (1993). Thorax with macrochaetae on
thoracic tergites as in Fig. 2: Th. II with 4 macrochaetae in group I and 5 (6) in group
II. Macrochaetal formula of coxae 3/4+1,3/4+2 (Fig. 9). Trochanteral organ with 28-35
smooth setae (Fig. 10). Inner tibiotarsal differentiated setae large, finely ciliate, and
clearly different from the normal ciliate setae, only distalmost one on third pair of legs
straight and smooth. Tenent hairs strongly clavate and slightly longer than inner
margin of unguis. Unguis with 3 small inner teeth. Outer edge of unguiculus smooth,
without tooth (Fig. 11).
















Florida Entomologist 80(4)


Abdomen: Dorsal chaetotaxy of Abd. I-III as in Fig. 2. Abd. I with 10 macrochaetae
on each side; Abd. II with 3 macrochaetae in M3 arch, 3 inner to M3 arch, and 1 lateral
on each side; Abd. III with 3 dorso-central (Group I) and 5 lateral macrochaetae
(Group II) on each side. Anterior part of Abd. IV with 10-13 macrochaetae on each
side; posterior part with 5 + 5 macrochaetae arranged in U-shape, inside which 7-9
macrochaetae present (Fig. 5). Except numerous small ciliate setae, ventral tube with
3 + 3 ciliate macrochaetae on anterior face, line connecting proximal one (Pr) and ex-
ternal-distal one (Ed) oblique to ventral groove (Fig. 12); posterior face with 5 smooth


4


/ '"'nrr


X 6t


Figs. 1-8. Homidia pentachaeta n. sp. (type specimens): Fig. 1. habitus; 2. semi- di-
agrammatic dorsal chaetotaxy of Thor. II-Abd. III (right side), 3. dorsum of head; 4.
body showing color pattern; 5. semi-diagrammatic dorsal chaetotaxy ofAbd. IV.; 6. an-
tennal apical bulbs; 7. labrum, 8. labial triangle (left side).


December, 1997















Li & Christiansen: New Homidia from China


subapical setae, median one much shorter than others (Fig. 13); each lateral flap with
6 smooth setae (Fig. 14). Ratio of manubrium /(dens + mucro) = 1.0 / 1.2-1.3. Basal half
of dens with 31-45 spines along inner edge in adult; basal setae (bsl & bs2) subequal
and multilaterally ciliate; proximal-internal seta (pi), much thinner and longer than
bs (Fig. 15). Male genital plate not seen.
The name of this new species is derived from the Greekpente chaite = five chaetae.
It refers to the unique feature of the species-the presence of 5 lateral macrochaetae
on each side of Abd. III (in contrast to the 3-4 setae found in all other species).
Found only at the type locality in the soil among grassroots under a willow woods.
Holotype female and 6 female paratypes. China: Jiangsu: Nanjing: Baguazhou,
IX-17-1994, collection number 8417, coll. by Jian-xiu Chen. Deposited in Department
of Biology, Nanjing University, China.
Remarks: For convenience, we name the proximall seta" and "external-distal seta"
on the anterior face of ventral tube as "Pr" and "Ed" respectively. In this new species,
there are more macrochaetae than in most species of the genus, especially in the dor-
sal cephalic groups, group II of Th. II, and dorso-central group on the posterior part


9

lb N


14


15


^h,


Figs. 9 15 Homidia pentachaeta n. sp. (type specimens): Fig. 9. macrochaetae of
coxae, a. leg I, b. leg II, c. leg III; 10. trochanteral organ; 11. hind foot complex; 12. an-
terior face of ventral tube; 13. posterior face of ventral tube (showing apical smooth se-
tae); 14. right lateral flap of ventral tube; 15. basal part of dens (bsl & bs2-basal
setae, pi-proximal-internal seta).

















Florida Entomologist 80(4)


of Abd. IV. The unique character of the species lies in the presence of 5 lateral macro-
chaetae on each side ofAbd. III, whereas all other species have 4 (3) macrochaetae. It
is similar to the Korean species H. similis Szeptycki and H. sinensis Denis; however,
it differs from both as shown below:


Character H. pentachaeta H. similis H. sinensis

Labral papillae absent present absent
Labral setae a2 > b2 a2 < b2 a2 = b2
Labial basal seta L1 smooth ciliate ?
Dorsal cephalic chaetotaxy 4-6A, 30, 6S 3A, 30, 5S 3A, 30, 4S
Coxal macrochaetae 3/4+1,3/4+2 3/4+1,3/4+3 3/?'/ 4 +2
Macrochaetae ofAbd III in group I 3 2 3
in group II 5 4 4
Position of line connecting Pr & Ed oblique parallel ?
to median furrow of ventral tube


In addition H. penatachaeta differs from H. sinsensis in having 10-13 anterior setae
per side on the 4th abdominal segment as compared with 8 for H. sinensis. It also dif-
fers in chaetotaxy of the third thoracic and first abdominal segments (compare figures
2, 9). H. sinensis was originally described as a variation of H. sauteri but it differs
from H. sauteri in these last two features and should be considered a valid distinct
species.

ACKNOWLEDGMENTS

We thank Mr. Liu Ren-hua of Nanjing University, who made the final drawings for
this paper. We also thank Judith Najt and Jean Marc Thibaud of the Paris Museum,
who made the types of H. sinensis available to us. Thanks are also given to Dr. Peter
Bellinger of the Department of Biology, California State University, USA, and Prof.
Jian-xiu Chen in the Department of Biology, Nanjing University, China, for their use-
ful help to our work.

REFERENCES CITED

CHEN, J. X., AND K. A. CHRISTIANSEN. 1993, The genus Sinella with special reference
to Sinella S.S. (Collembola: Entomobryidae) of China. Oriental Insects 27: 1-
54.
DENIS, J. R. 1929. Notes sur les Collemboles r6coltes dans ses voyages par le Prof. F.
Silvestri. Second Note sur les Collemboles D'Extreme Orient. Bull. Lab. Zool.
Gen. Agrar. Portici 22: 305-320.
SZEPTYCKI, A. 1973. North Korean Collembola. I. The genus Homidia Bdrner 1906
(Entomobryidae). Acta Zool. Cracov.18 (2):23-39.
UCHIDA, H. 1943. On Some Collembola-Arthropleona from Nippon. Bull. Tokyo Sci.
Mus., Tokyo 8: 1-18.


December, 1997
















LaSalle & Pefia: A New Species of Galeopsomyia


A NEW SPECIES OF GALEOPSOMYIA (HYMENOPTERA:
EULOPHIDAE: TETRASTICHINAE): A FORTUITOUS
PARASITOID OF THE CITRUS LEAFMINER, PHYLLOCNISTIS
CITRELLA (LEPIDOPTERA: GRACILLARIIDAE)

JOHN LASALLE' AND JORGE E. PENA2
International Institute of Entomology, 56 Queen's Gate, London, SW7 5JR, UK

'Tropical Research and Education Center, University of Florida
Homestead, Florida, 33031, USA

ABSTRACT

Galeopsomyia fausta LaSalle sp.n. (Hymenoptera: Eulophidae: Tetrastichinae) is
described as a fortuitous parasitoid of the citrus leafminer,Phyllocnistis citrella Stain-
ton (Lepidoptera: Gracillariidae: Phyllocnistinae). This species is widely distributed in
the Neotropics, being known from Mexico and Puerto Rico to Argentina. G. fausta is
the first species of Galeopsomyia which is not associated biologically with galls. G.
fausta represents an example of an indigenous parasitoid recruited onto an invading
pest species, and the implications of this for the valuation of biodiversity are dis-
cussed.

Key Words: Phyllocnistis citrella, parasitoids, biological control, biodiversity

RESUME

Se describe Galeopsomyia fausta LaSalle sp.n. (Hymenoptera: Eulophidae: Tetras-
tichinae) un parasitoide fortuito del minador de los citricos, Phyllocnistis citrella
Stainton (Lepidoptera: Gracillariidae: Phyllocnistinae). La especie G. fausta esta dis-
tribuida ampliamente en el neotr6pico, desde M6xico, Puerto Rico hasta Argentina. G.
fausta es la primera especie de Galeopsomyia la cual no se encuentra asociada con in-
sectos productores de agallas. G. fausta es un ejemplo caracteristico de un parasitoide
native atacando una especie plaga invasora. Se toma este ejemplo para discutir sus
implicaciones en lo que respect a el valor de la biodiversidad.




The citrus leafminer (CLM), Phyllocnistis citrella Stainton (Lepidoptera: Gracilla-
riidae: Phyllocnistinae), has only recently invaded the tropical and semi-tropical ar-
eas of the New World. The arrival of P. citrella in Florida in 1993, and its rapid spread
through the Neotropics, has been documented by Heppner (1993), and Knapp et al.
(1995). These papers offer much additional information on the biology, distribution,
and management of P. citrella.
Heppner (1993) recorded about 30 species of Asian parasitoids of P. citrella. There
are now almost 80 species of parasitoids which have been reared from P. citrella
throughout the world (Schauff et al., submitted). Many of these are indigenous para-
sitoids which have moved over onto P. citrella as it has spread, and there are already
over 20 such species known from the New World (Schauff et al., submitted; Table 1).
A few of these species appear to be capable of exerting substantial levels of control on
the P. citrella populations. The purpose of this paper is to describe one of these species,
Galeopsomyia fausta LaSalle sp.n., and comment on the importance these indigenous
species can play in biological control programs.

















Florida Entomologist 80(4)


TABLE 1. INDIGENOUS NEW WORLD PARASITOIDS RECORDED ATTACKING CITRUS LEAF-
MINER (COMPILED FROM SCHAUFF ET AL., SUBMITTED).

Species


EULOPHIDAE
C Iry.s c tiort. sp.
( ;. *. .. ...,', sp.
Cirrospilus nigrivariegatus Girault
Cirrospilus sp. A

Cirrospilus sp. B
Cirrospilus sp. C

Closterocerus cinctipennis Ashmead
Closterocerus sp. or spp.
Diglyphus begin (Ashmead)
Elachertus sp. or spp.
Galeopsomyia fausta LaSalle sp.n.

Horismenus sardus (Walker)
Horismenus sp. or spp.

Pnigalio minio (Walker)
Pnigalio sp. or spp.
Sympiesis sp.
Zagrammosoma americanum Girault
Zagrammosoma multilineatum (Ash-
mead)
Zagrammosoma sp. or spp.


ELASMIDAE
Elasmus tischeriae Howard
Elasmus sp. or spp.

EUPELMIDAE
Eupelmus sp.

PTEROMALIDAE
Catolaccus aeneoviridis (Girault)


Honduras
Colombia, Mexico
USA: Florida
Honduras, Mexico, Nicaragua, USA: Flor-
ida, Venezuela
Honduras, Peru
Argentina, Brazil, Colombia, Honduras,
Mexico
USA: Florida, Texas
Colombia, Honduras, Mexico
USA: Florida
Argentina, Honduras, USA: Florida
Argentina, Brazil, Colombia, Honduras,
Mexico, Nicaragua, Puerto Rico
USA: Florida
Brazil, Colombia, Honduras, Mexico, Nic-
aragua, Puerto Rico
USA: Florida
Mexico, USA: Florida, Texas
USA: Florida
USA: Florida
Colombia, Mexico, USA: Florida

Mexico, Puerto Rico, USA: Texas,
Venezuela


Mexico, USA: Florida
Brazil, Colombia, Mexico, Nicaragua


Brazil


USA: Florida


Galeopsomyia fausta as a biological control agent of P. citrella

G. fausta is a widespread species that has been recorded as a parasitoid of P. cit-
rella from throughout the Neotropics. We have examined material from Puerto Rico,
Mexico, Nicaragua, Honduras, Colombia, Brazil and Argentina, and it will certainly
be present in many other countries in the region.


December, 1997

















LaSalle & Pefia: A New Species of Galeopsomyia


Surveys have repeatedly identified G. fausta as one of the important indigenous
parasitoids of P. citrella (Cano 1996, Cano et al. 1996, Castano et al. 1996, Cave 1996,
Cobo 1996, de la Llana 1996, Martinez 1996: all as Galeopsomyia sp.).
Cano (1996) collected parasitoids in different areas of Nicaragua, and found G.
fausta to be the most abundant parasitoid, representing 19-59% of the parasitoid spe-
cies composition collected from pupae ofP. citrella in 1995 and 1996. Cano (1996) dem-
onstrated that G. fausta was abundant in the dry-subtropical region of Nicaragua
comprising 45% of the fauna followed by Horismenus sp., (36%), Cirrospilus sp. (9%)
and Elasmus sp. (9%). Similar results were reported by de la Llana (1996). G. fausta
was observed parasitizing P. citrella throughout the year, with highest peaks observed
in January, July and October 1995-1996 (Cano 1996). Levels of 28 and 68% parasiti-
zation of pupae were observed during June 1995 and January 1996 (Cano 1996).

Biological Considerations of Galeopsomyia fausta

G. fausta is the first species of Galeopsomyia which is known to attack leafminers.
All other species of Galeopsomyia attack galls, mostly as parasitoids of Cynipidae or
Cecidomyiidae, but occasionally as inquilines (LaSalle 1994). The native host of G.
fausta is not known. The wide distribution of G. fausta on P. citrella in the short period
of time that P. citrella has been in the Neotropics suggests that this species has an in-
nate ability to switch hosts onto P. citrella, rather than having made a single host
switch and then spreading.

Galeopsomyia fausta and Biodiversity Considerations

Various authors have claimed that one of the values of conserved biodiversity is
that it represents a pool of potential biological control agents (Waage 1991, LaSalle &
Gauld 1993, LaSalle 1993). Thus, we are retaining the ability to control future pest
problems in a manner that is both environmentally and economically sound. Without
this option for biological control, we may have to rely upon control measures which
will accelerate the present decline in environmental quality.
The spread of P. citrella in the New World has provided support for these claims.
The only species of introduced parasitoid which has been established in the New
World is Ageniaspis citricola Logvinovskaya in Florida (Hoy & Nguyen 1994, Knapp
et al. 1995, Hoy et al. 1995), Louisiana (Johnson et al. 1996), Bahamas (Hoy et al.
1995), and Honduras (Castro et al. 1996, Cave 1996). However, a large complex of na-
tive parasitoids are now attacking P. citrella, and in many cases native species are
providing control which is as effective or more effective than that supplied byA. citri-
cola (Cano 1996, Cano et al. 1996, Castano et al. 1996, Cave 1996, Cobo 1996, de la
Llana 1996, French & Legaspi 1996, Gravena 1996, Martinez 1996, Pena et al. 1996,
Perales & Garza 1996, Perales et al. 1996).
Table 1 lists over 20 indigenous species which have now been recorded from P. ci-
trella in the New World (Schauffet al., submitted). Many of these species are inciden-
tal and will offer no substantial control. However, others of these species appear to
play a major role in regulating the population levels of P. citrella (such as species of
Cirrospilus, and G. fausta).
Several papers have discussed the relevance of being able to provide direct mea-
sures of the value of preserving biodiversity, and methods of attempting to do it (sev-
eral chapters in Wilson 1988, Orians et al. 1990, Swanson 1995, Kunin & Lawton,
1996). The recruitment of indigenous parasitoids onto an introduced pest provides a
direct method of quantifying one small portion of the value of conserved biodiversity.
Evaluation of the cost effectiveness of biological control using introduced parasitoids

















Florida Entomologist 80(4)


has been performed on many occasions (e.g. Dean et al. 1979, van den Bosch et al.
1982, Norrgard 1988a, b, DeBach & Rosen 1991). This methodology can just as easily
be applied to indigenous parasitoids to quantify one of the financial benefits of biodi-
versity.

MATERIAL AND METHODS

Terminology follows LaSalle (1994). The term basigastral carina is borrowed from
the ant workers to describe a strong, transverse carina along the anterior margin of
the first gastral tergite; any longitudinal carinae extending posteriorly from the basi-
gastral are termed basigastral costulae.

Galeopsomyia fausta, LaSalle sp.n.
(Figs. 1-9)

Galeopsomyia sp.: Cano, 1996; Cano et al., 1996; Castafo et al., 1996: Cave, 1996;
Cobo, 1996; de la Llana, 1996; Martinez, 1996.

Diagnosis

Body strongly sclerotized. Gaster (Figs. 4, 5) non-collapsing in dried specimens,
distinct basigastral carina and basigastral costulae present; petiole (Fig. 4, 6) distinct,
wider than long, strongly sculptured dorsally; gastral tergites, and particularly the
first one generally lightly sculptured, terminal gastral tergites reticulate dorsally.
Propodeum (Figs. 3, 4) strongly reticulate, with a paraspiracular carina, and posterior
edge sharply margined. Malar space (Fig. 2) with a triangular fovea below eye, the
bottom of this fovea with sculpture. Fore wing (Fig. 7) with 4-5 setae on dorsal surface
of submarginal vein.

Female

Length 1.15-1.7 mm. Head, mesosoma, metasoma and coxae black, usually with
dark blue metallic shine which is particularly strong on the mesosoma. Antenna with
scape yellow to light brown; pedicel yellow to light brown, with dark dorsal patch; fu-
nicle dark brown. All femora predominantly brown to dark brown, generally brown to
yellow apically. Tibiae yellow to light brown. Tarsal segments 1-3 yellow to white, seg-
ment 4 brown.
Head (Figs. 1, 2) strongly sculptured. Scrobal cavity without distinct sulci, but
with a longitudinal median ridge. Face with strong furrow between torulus and
mouth margin; this furrow carinate ventrally. Clypeus distinctly bilobed. Malar space
with a triangular fovea below eye, the bottom of this fovea with sculpture.
Antenna (Fig. 8) with 3 anelli, 3 funicular segments, 3 segmented club. Each suc-
cessive funicular segment only very slightly increasing in length; funicular segments
together slightly longer than club.
Mesosoma (Fig. 3) with distinct reticulation. Mesoscutum with notaulus very deep;
median line present as a broad, vaguely defined furrow; adnotaular setae in 1-2 rows.
Scutellum with submedian lines broad and shallow; sublateral lines broad and later-
ally carinate; distinct transverse groove along posterior margin; several (4-6) pairs of
scattered setae, these small and indistinct when examining specimens under normal
magnification. Propodeum strongly reticulate, with a paraspiracular carina, and pos-
terior margin sharply margined.


December, 1997
















LaSalle & Peria: A New Species of Galeopsomyia


Figs. 1-6. Galeopsomyia fausta, 9. 1, head, frontal view. 2, head, side view. 3, me-
sosoma. 4, propodeum, petiole, base of gaster. 5, gaster. 6, propodeum, petiole, base of
gaster, lateral view.

















Florida Entomologist 80(4)


Fore wing (Fig. 7) without even rudimentary postmarginal vein. Dorsal surface of
submarginal vein with 4-5 setae.
Metasoma (Figs. 5, 6). Petiole distinct, wider than long, strongly sculptured dor-
sally. Gaster with distinct basigastral carina and basigastral costulae present; gastral
tergites, and particularly the first one generally lightly sculptured, terminal gastral
tergites reticulate dorsally. Gastral tergites 1-4 each decreasing slightly in length
compared to the previous segment, so that tergite 4 is the shortest gastral tergite;
tergite 5 slightly longer than tergite 4, but shorter in length than tergites 1 and 2.

Male

Length 1.15-1.35 mm. Similar to female except in sexual differences in genitalia
and antennae. Antenna (Fig. 9) with 4 funicular segments. Funicular segments with-
out basal whorls of long setae, with sparsely scattered setae which are shorter than
the width of the funicle. Fl shorter than remaining segments, F2-4 subequal in
length. Scape with ventral plaque situated in apical half of scape, 0.25-0.28 the total
length of scape.

Discussion

Galeopsomyia may be distinguished from other genera of Tetrastichinae using the
key provided by LaSalle (1994). The genus can be recognized by the combination of the
following characters: body strongly sclerotized, with gaster non-collapsing and all
gastral tergites reticulate dorsally; propodeum strongly reticulate, with a paraspirac-
ular carina, and a transverse carina along posterior margin; malar space with a tri-
angular fovea below eye, this generally with some sculpture; submarginal vein with
2 or more dorsal setae.
G. fausta can be distinguished from other species of Galeopsomyia by the combi-
nation of the following characters: distinct basigastral carina and basigastral costulae
present; petiole distinct, wider than long, strongly sculptured dorsally; gastral terg-
ites, and particularly the first one, not as strongly reticulate dorsally as other mem-
bers of the genus; fore wing with 4-5 setae on dorsal surface of submarginal vein (as
opposed to 2 or 3 in most members of this genus); gastral tergites 1-4 each decreasing
slightly in length, tergite 5 slightly longer than tergite 4, but not distinctly longer
than segments 1 and 2.
G. fausta is the only species of Galeopsomyia with a distinct petiole. Other mem-
bers of Galeopsomyia are also generally lacking a basigastral carina. The only other
Galeopsomyia species which has a basigastral carina like G. fausta is the Brazilian G.
viridicyanea (Ashmead). This species differs from G. fausta in lacking a distinctly vis-
ible petiole, having all gastral tergites with very strong reticulate sculpture, and hav-
ing gastral tergites 1-5 each increasing slightly in length compared to the previous
segment, so that tergite 5 is distinctly the longest gastral tergite.

Material Examined

Note: all specimens ex. Phyllocnistis citrella on citrus.
Holotype 9, MEXICO, Veracruz, Cuitlahuac, 20-xi.1995, N. Bautista Mtz.
(BMNH).
679, 66 Paratypes: PUERTO RICO: Adjuntas, 6.ii.1996 (29 UPRM). MEXICO:
Veracruz, Cuitlahuac, 20-xi.1995, N. Bautista Mtz. (3 CPMM, 2 2 INIA, 2 BMNH);
Veracruz, Cruz Naranjos, 9.iii.1995, R. Mateos C. (19 CPMM). HONDURAS: Fco


December, 1997















LaSalle & Pefia: A New Species of Galeopsomyia 467






















8









Figs. 7-9. Galeopsomyia fausta. 7, 2 forewing. 8, 2 antenna. 9, 6 antenna.


Morazan, El Zamorano, 31.x.1995, A. Guillen (32 BMNH, 22 CNC); Fco Morazan, El
Zamorano, 8.xi. 1995, A. Guillen (1 BMNH, 2 2 FSCA); Fco Morazan, San Antonio de
Oriente, El Zamorano, 17.xi.1994, R. Cordero (49 EAPZ); Fco Morazan, San Antonio
de Oriente, El Zamorano, 12.xii.1994, R. Cordero (19 USNM); El Paraiso, Yuscaran,
15 km antes de Yuscaran, 8.ii.1995, R. Cordero (19 USNM); Atlantida, La Ceiba,
Buena Vista, 3.iii.1995, R. Chavez (19 USNM); Atlantida, La Ceiba, Buena Vista,
22.ix.1995, J. Ortega (1 USNM); Atlantida, 45 km W Tela, 22.i.1996, A. Guillen (1
USNM). NICARAGUA: C. Azules, Masatepe, 1.viii.1995, A. de la Llana (29 SEA); C.
Azules, Masatepe, 14.viii.1995, A. de la Llana (19 CENA); C. Azules, Masatepe,
4.ix.1995, A. de la Llana (19 CENA); Jinot6ga, Dorranli, 19.vii.1995, A. de la Llana
(19 SEA); Leon, Leon, 26.vii.1995, J. Hernandez (19 BMNH); Leon, Leon,
28.vii.1995, J. Hernandez (1 CENA). COLOMBIA: Valle, Palmira, viii.1995, L. Rojas
& F. Garcia (39 3d BMNH, 29 3d USNM). BRAZIL: Sao Paulo, Jaguariuna,
15.viii.1996, J. L. de Silva (49 DCBU, 29 BMNH, 19 USNM, 19 CNC); Sao Paulo,
Valinhos, 24.v.1996 (2 DCBU); Sao Paulo, Valinhos, vi.1996, Paiva (19 DCBU). AR-
GENTINA: Tucuman, El Cadillal, 12.iii.1997, E. Frias & P. Colombres (99 IML, 49
MLP, 2 BMNH, 2 CNC).

















Florida Entomologist 80(4)


Etymology

The species name fausta comes from the Latin for favorable or fortunate. It signi-
fies that this species is a fortuitous biological control agent.

Biology
G. fausta has clearly moved over onto P. citrella from some other host(s), but the
identity of its native host or hosts remains unknown.
Cobo (1996) studied Colombian parasitoids of CLM. She reported that G. fausta (as
Galeopsomyia sp.) was an important parasitoid ofP. citrella, which attacked the larva,
prepupa and pupa. It paralyzes the host, and later deposits its eggs near the host.
When several eggs are deposited at the same time, the first closing larva feeds on the
remaining eggs. Eggs are hymenopteriform, round in one end and sharp at the oppo-
site end, and small and almost transparent when newly oviposited. After oviposition,
the host stops any movement and becomes darker. The parasitoid larva develops
quickly, pupating at a distance from the host. The pupa is initially pale yellow, and
darkens to a shiny black color. G. fausta is mostly a pupal parasitoid, parasitizing
87.77% pupae, 9.83% prepupae, 2.39% larvae (Cobo, 1996).
G. fausta appears to be mainly thelytokous, with only occasional males. Of the 74
type specimens mentioned in this paper, only 6 were males, and these were all from
the same locality (Colombia) and date. Since this paper was submitted, another 150
specimens were sent to us from Brazil, all of which were female.

ABBREVIATIONS
BMNH The Natural History Museum, London, UK
CNC Canadian National Collection, Ottawa, CANADA
CPMM Coleccion de Insetos, Instituto de Fitosanidad, Colegio de Postgraduados,
Montecillo, MEXICO
DCBU Departemento de Ciencias Biol6gicas, Universidade Federal de Sao Carlos,
Sao Carlos, SP (Sao Paulo), BRAZIL
EAPZ Departemento de Proteccion Vegetal, Escuela Agricola Panamericana, El
Zamorano, HONDURAS
FSCA Florida State Collection ofArthropods, Gainesville, Florida, USA
IML Fundaci6n e Instituto Miguel Lillo, Universidad Nacional de Tucuman, San
Miguel de Tucuman, ARGENTINA
INIA Instituto Nacional de Investigaciones Agricolas, Secretaria de Agricultura y
Ganaderia, Chapingo, MEXICO
CENA Museo de Entomologia, Centro Nacional de Protection Vegetal, Ministerio
de Agriculture y Ganaderia, Managua, NICARAGUA
MLP Facultad de Ciencias Naturales y Museo, Universidad Nacional de La Plata,
La Plata, ARGENTINA
SEA Servicio Entomol6gico Aut6nomo, Museo Entomol6gico, SEA, Leon, NICA-
RAGUA
UPRM Department of Entomology, University of Puerto Rico, Mayaguez, PUERTO
RICO
USNM United States National Museum (Natural History), Washington, D.C., USA

ACKNOWLEDGMENTS
Many people have kindly made specimens or information available to us. These in-
clude N. Bautista Mtz., E. Cano, R. Cave, V. A. Costa, A. de la Llana, G. Evans, P. Fi-
dalgo, F. Garcia, J. Hernandez, A. Pantoja, A. Penteado-Dias, M. Schauff, A. Trochez.


December, 1997

















LaSalle & Pefia: A New Species of Galeopsomyia


Space and facilities during this study were kindly provided to JL by the Depart-
ment of Entomology, The Natural History Museum, London; technical assistance from
the SEM and photography units of the BMNH is also gratefully acknowledged; special
thanks to Nick Hayes (BMNH) for the printing of the photomicrographs.
Florida Agricultural Experiment Station Journal Series No. R-05660.

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hoja. Proyecto FAO/TCP/NIC/4551 (A). Managua, Nicaragua, 4-6 June 1996.
SCHAUFF, M. E., J. LASALLE, J., AND G. A. WIJESEKARA. Submitted. The genera of
chalcid parasites (Hymenoptera: Chalcidoidea) of citrus leafminer, Phyllocnis-
tis citrella Stainton (Lepidoptera: Gracillariidae).
SWANSON, T. M. (ed.). 1995. The economics and ecology of biodiversity decline: the
forces driving global change. Cambridge University Press. Cambridge. 162 pp.
VAN DEN BOSCH, R., P. S. MESSENGER, AND A. P. GUTIERREZ. 1982. An Introduction
to Biological Control. Plenum Press. New York. 247 pp.
WAAGE, J. K. 1991. Biodiversity as a resource for biological control. pp. 149-162, in
Hawksworth, D. L. (ed.) The Biodiversity of Microorganisms and Invertebrates:
Its Role in Sustainable Agriculture. CAB International, Wallingford, UK.
WILSON, E. 0. (ed.). 1988. Biodiversity. National Academy Press. Washington, D.C.
521 pp.


December, 1997

















Shapiro et al.: Citrus Root Resistance Bioassay


RESISTANCE OF CITRUS ROOTSTOCKS AND GLYCOSMIS
PENTAPHYLLA AGAINST LARVAL DIAPREPESABBREVIATUS
(COLEOPTERA: CURCULIONIDAE) IN LIVE ROOT OR DIET-
INCORPORATION ASSAYS

JEFFREY P. SHAPIRO, KIM D. BOWMAN AND HUNTER S. SMITH
USDA, Agricultural Research Service, 2120 Camden Road, Orlando, Fl 32803

ABSTRACTS

The growth of larval Diaprepes abbreviatus L. was measured after rearing them on
roots of rutaceous seedlings for 35 or 42 days. Larvae were fed on seedlings of two
common citrus rootstocks, two new hybrids that are under development as rootstocks,
and one citrus relative. Live weights of larvae reared on Carrizo or Swingle rootstocks
for 42 days increased an average of 10.3- and 10.2-fold, respectively; weight increases
on the citrus hybrids HRS-802 and HRS-896 for 35 days averaged 7.6- and 6.1-fold, re-
spectively; and weight increase on (r ... ... pentaphylla Retzius for 42 days aver-
aged 2.5-fold. A bioassay to test for potential phytochemical sources of resistance
against the larvae was developed by incorporating finely milled roots into larval diet.
Milled root samples were incorporated into a standard semi-defined diet at 5% con-
centrations (w/v), and growth of larval weevils was recorded following a 32-day feed-
ing period. Roots collected from uninfested control seedlings in the previous
experiment were used. On diet containing no roots, mean larval weight increased
16.8-fold, while weights increased 13.9-fold on diet containing roots of Carrizo, 12.0-
fold on Swingle, 15.1-fold on HRS-802, 12.3-fold on HRS-896, and only 5.5-fold on G.
pentaphylla. Both tests indicate that G. pentaphylla may represent a source of root re-
sistance to D. abbreviatus, and the diet-incorporation tests indicate potential phy-
tochemical or microbial sources of resistance.

Key Words: Diaprepes abbreviatus, citrus root weevil, rootstock resistance, larval
growth, diet-incorporation assay

RESUME

Fue medido el crecimiento de larvas de Diaprepes abbreviatus L. criadas en raices
de plantulas de rutaceas durante 35 o 42 dias. Las larvas fueron alimentadas en dos
patrons comunes de citricos, dos nuevos hibridos que estan bajo desarrollo como pa-
trones, y un pariente de los citricos. El crecimiento en los patrons Carrizo o Swingle
durante 42 dias promedi6 10.3 y 10.2 veces, respectivamente; el crecimiento sobre los
hibridos HRS-802 y HRS-896 durante 35 dias promedi6 7.6 y 6.1 veces, respectima-
mete, y el crecimiento en (r ... ... pentaphylla durante 42 dias promedi6 2.5 veces.
Se desarroll6 un bioensayo para probar fuentes potenciales fitoquimicas de resisten-
cia contra la larva mediante la incorporaci6n de raices finamente molidas a la dieta
larval. Las muestras de raices molidas fueron incorporadas a una dieta estandar se-
midefinida a concentraciones del 5% (peso/volumen), y el peso de las larvas fue regis-
trado siguiendo un period de 32 dias. Fueron usasas las raices colectadas de las
posturas control en el experiment previo. En una dieta sin raices, el peso medio lar-
val aument6 16.8 veces, mientras que los pesos aumentaron 13.9, 12.0, 12.3 y 5.5 ve-
ces sobre la dieta que contenia raices de Carrizo, Swingle, HRS-802, HRS-896 y G.
pentaphylla, respectivamente. Ambos ensayos indicaron que G. pentaphylla puede ser
una fuente de resistencia radicular hacia D. abbreviatus, y que los ensayos de incor-
poraci6n a las dietas sirven para indicar fuentes fitoquimicas o microbianas de resis-
tencia.

















Florida Entomologist 80(4)


Cultivated varieties of crop plants are routinely evaluated for resistance of foliage
or fruit to insect feeding and damage (Smith 1989, Panda & Khush 1995). Evaluating
insect resistance in roots is less common, however, especially for long-lived horticul-
tural crops such as citrus. In Florida, the citrus root weevil Diaprepes abbreviatus L.
(Coleoptera: Curculionidae) causes most of its damage to citrus trees during the lar-
val stage while feeding on the root system of the rootstock. There, larvae strip bark
from the roots of the tree, weakening and eventually killing the root once its circum-
ference is fully girdled. We recently reported results from a whole-plant test designed
to compare root damage, larval survival, and larval growth among citrus rootstock
cultivars, hybrids, and other species of citrus relatives (Shapiro & Gottwald 1995).
The phytochemical composition of citrus roots has been well studied (Shapiro
1991; Nordby & Nagy 1981, Gray & Waterman 1978). Structural characterizations of
numerous coumarins, alkaloids, flavonoids, and limonoids from citrus roots have been
reported, but with few references to biological activities. These classes of phytochem-
icals include many examples of defensive compounds. To discover whether such com-
pounds impart any resistance against Diaprepes, roots must first be screened for
biological activity, then the chemical source of an activity must be identified. A suc-
cessful bioassay should enable rapid tests of small quantities of root material from a
large number of samples. A whole-plant assay has already been developed (Shapiro &
Gottwald 1995). Of eight commercial rootstocks and new hybrids that were tested in
that assay, only one Swingle showed some resistance, in contrast to an earlier study
(Beavers & Hutchison 1985). This observation was based on three parameters mea-
sured in the bioassay: larval weight gain, larval mortality, and root damage relative
to uninfested control plants. The last parameter was measured by root volume, root
weight, and by digitally integrating the visible areas of roots from photographs, all of
which correlated well.
To enable the identification of roots that deter larval growth and of the active phy-
tochemicals extracted from them, we have designed a simple diet-incorporation assay,
and here compare it with our routine whole-plant assay for resistance to Diaprepes
larvae (Shapiro & Gottwald 1995).

MATERIALS AND METHODS

Insects

Larvae were obtained from a weevil colony maintained in isolation on a semi-de-
fined diet for over 6 yr, with only occasional infusion of adult weevils from citrus
groves located near Lake Jem in central Florida and in Homestead, Florida. Larvae
from field-collected adults were added once or twice each year and comprised no more
than 20% of the larvae in the colony. Larvae at one month of age were taken from the
colony and individually weighed. Groups of ten were selected at average weights of
25-30 mg/group for placement on seedlings with one group of ten per seedling.

Plants

Seeds for rootstocks or hybrids were obtained from germplasm grown at the US
Horticultural Research Laboratory (USHRL) Foundation Farm in Leesburg, FL, and
for G. pentaphylla from the Florida Division of Plant Industry Arboretum in Winter
Haven, FL. Test seedling plants were grown from seed at the USHRL Foundation
Farm and transferred for weevil challenges to the USHRL greenhouses in Orlando,


December, 1997

















Shapiro et al.: Citrus Root Resistance Bioassay


Seedling Challenges

Challenges were conducted as described by Shapiro and Gottwald (1995), except
that the duration of those tests was 44 days. The starting weight of each Diaprepes
larva was taken prior to placing ten larvae on each plant. Larvae were placed at 8 cm
depth in the soil, evenly distributed midway between the trunk of a seedling and the
circumference of the 1-gal pot. Each test consisted of seven replicates of each cultivar,
one plant per replicate. Larvae were allowed to feed in the greenhouse on the roots of
5 selections including two widely used commercial rootstocks (Carrizo and Swingle;
42 days, from June 11 to July 23, 1996), one citrus relative, G. pentaphylla (42 days,
from June 13 to July 25, 1996), and two citrus hybrids that are in final stages of test-
ing as rootstocks (HRS-802 and HRS-896; 35 days, from May 22 to June 26, 1996).
Seedlings were removed from pots, larvae were recovered, and survival rates and the
live weight of each surviving larva were recorded.

Diet-Incorporation Tests

Roots for diet-incorporation assays were obtained from uninfested seedlings col-
lected from seedling challenge experiments. Following storage at -80fC, roots were
milled in a centrifugal mill (Retsch ZM-1000, Brinkmann, Westbury, NY) at 10,000 or
15,000 rpm to < 0.5-mm particle size. Diet for incorporation was prepared by first add-
ing 14 g agar to approximately 800 ml water, and heating to approximately 100 C
while mixing with a Braun (Lynnfield, MA) type 4169 hand-held homogenizer. As the
agar cooled, 184 g of citrus root weevil diet premix #1675F (Bio-Serve, Frenchtown,
NJ), which is used for routine rearing, was added. The mixture was thoroughly mixed
and diluted to 1 L with water. Diet was distributed to 100-ml beakers, and 5 g of roots
were blended with 100 ml of diet when diet had cooled to a temperature of approxi-
mately 50 C, the melting point of the agar used in the diet. Approximately 15 ml of diet
were rapidly poured into each plastic 30-ml shot cup (Jet Plastica, Hatfield, PA), al-
lowed to cool, and dried for approximately 6 h under a laminar flow hood. Controls con-
sisted of diet only with no roots added. One larva was added to each of 30 cups of diet
per treatment, cups were covered, and larvae were allowed to feed for 32 days in the
insectary at an approximate temperature of 29~C under a light regime of 10:14 (L:D).
Larvae were then separated from the diet and individually weighed for final weights.

Statistics

One-way ANOVA and post-hoc comparison of means (Tukey's HSD) tests were per-
formed using the Statistica (StatSoft 1995) version 5.0 Basic Statistics module.


RESULTS AND DISCUSSION

Larvae that fed for 35 days on roots of the two hybrid selections, HRS-802 and
HRS-896, increased 7.6- and 6.1-fold over their initial live weight, to 222 and 184 mg,
respectively (Table 1). Those that were fed for 42 days on the two commercial root-
stocks, Carrizo and Swingle, increased 10.3- and 10.2-fold over their initial live
weight, to 229 and 236 mg, respectively. In contrast, larvae that were fed on roots of
G. pentaphylla for 42 days increased only 2.5-fold over their initial live weight, to a
mean final weight of only 64 mg. There were no significant differences in mean final
weights among larvae grown on Carrizo, Swingle, and HRS-802. Larvae on HRS-896
weighed significantly less than those on Swingle and Carrizo, although seven more








































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Florida Entomologist 80(4)

















Shapiro et al.: Citrus Root Resistance Bioassay


days of feeding (42 days total) would have reduced this difference. However, larval
weight gain on all four cultivars was significantly different from the mean final weight
of the larvae fed on G. pentaphylla roots for 42 days. This was despite the fact that
starting weights of the larvae on HRS-802, HRS-896, and G. pentaphylla were signif-
icantly, though only slightly, greater than the larvae placed on Swingle or Carrizo.
In diet-incorporation assays, larvae were fed for 32 days on the standard rearing
diet with or without milled roots incorporated into it (Table 2). Changes in mean
weights of larvae fed on diet alone were greater than those fed on live roots. Larval
weights increased 16.8-fold on diet only, 13.9-fold on Carrizo, 12.0-fold on Swingle,
15.1-fold on HRS-802, 12.2-fold on HRS-896, and 5.5-fold on G. pentaphylla. Mean fi-
nal weights of all larvae except those fed on HRS-802 were significantly lower than
those fed on diet alone. Final weights of larvae fed on G. pentaphylla were signifi-
cantly lower than those of larvae fed either on diet alone or on diet with any of the
other root selections incorporated. In two additional diet-incorporation assays, larvae
fed on G. pentaphylla also gained significantly less weight than larvae on Swingle or
Carrizo (unreported results).
The results are significant from two perspectives. First, G. pentaphylla roots sup-
ported only very low growth rates, roughly one-third to one-fourth of those supported
by the other root systems. Previous results (Shapiro & Gottwald 1995) showed growth
rates on Swingle, Carrizo, and six other cultivars that were 2.8- to 5-fold greater than
the growth rate on G. pentaphylla in this study. On diet that incorporated milled roots,
larval growth rates on G. pentaphylla were approximately one-half to one-third as
high as on the other selections. Secondly, results from the diet-incorporation assay
mirrored those with live root tests. The comparison between larval growth rates on
live roots and growth on roots incorporated into diet is striking and repeatable.
These tests highlight the usefulness of the diet-incorporation assay as a possible
substitute for tests on live plants. Not only does the diet-incorporation assay require
only a fraction of a plant's total root system, but roots can be stored indefinitely at -80 C
for repeated tests whenever desired. Roots from any size of tree can also be readily col-
lected from the field and tested without destroying the tree. This will allow compara-
ble and parallel tests to be run on seedling, juvenile, and mature trees together.
Effects of resistance discovered in seedlings can thereby be compared to the potential


TABLE 2. CHANGE IN LARVAL WEIGHT AFTER FEEDING 32 DAYS ON 5 G MILLED ROOTS
ADDED TO 100 ML DIET.

Weight (mg SD)'

Starting Final Change

Diet only2 23.2 4.7a 390.0 + 99.4a 366.8 98.4a
Swingle 22.2 4.5a 266.3 116.8b 244.1 115.3b
Carrizo 22.6 4.4a 315.2 103.2b 292.6 102.2b
HRS-802 21.5 4.6a 325.0 + 86.8ab 303.5 87.3ab
HRS-896 23.1 + 4.6a 281.4 + 112.3b 258.3 112.0b
G. pentaphylla 20.6 4.0a 113.9 + 41.8c 93.3 40.6c

Mean + SD (N=30) of the weights of 30 larvae, all of which survived. Figures that are followed by the same
letter within a column are not significantly different (P < 0.05; ANOVA followed by Tukey's HSD test).
Cups with 'diet only' contained no ground roots.

















Florida Entomologist 80(4)


for resistance in other stages of tree grown from similar germplasm. Roots from plant
species entirely unrelated to citrus can also be tested for their effect on growth and
survival of Diaprepes larvae.
The diet-incorporation assay will also be very useful for further studies on chemical
or biological constituents of roots that may be responsible for inhibited larval growth.
Present results indicate a molecular or microbial source of larval growth inhibition. In
the diet-incorporation test, finely milled roots ofG. pentaphylla at only 5% concentra-
tion in diet produced the same relative growth inhibition seen in whole live roots. This
low requisite concentration of roots will reduce the time and sample size required to
identify active molecules or microbes. Although caveats in the use of diet assays for
identification of active compounds have been examined and discussed (Shapiro, 1992),
this assay affords a powerful tool for identification of active root constituents.
In the current search for active biochemical factors in citrus for defense of root-
stocks against Diaprepes, we have focused primarily on natural products that are ei-
ther small chemical constituents (Shapiro et al., 1988; Shapiro, 1991) or
macromolecules such as defense-related proteins (Mayer et al., 1995; McCollum et al.,
1995). Our discovery of growth-inhibiting activity in G. pentaphylla and the develop-
ment ofa bioassay to examine that activity should contribute to finding or developing
a rootstock with resistance to the weevil.

ACKNOWLEDGMENTS

The authors thank Thomas Moyer, Charles Spriggs, and Karin Crosby for their ex-
cellent technical assistance on this project, and Stephen Lapointe for writing the Re-
sumen. Funds for this project were made available from the Citrus Production
Research Marketing Order by the Division of Marketing and Development, Florida
Department of Agriculture and Consumer Services.

REFERENCES

BEAVERS, J. B., AND D. J. HUTCHISON. 1985. Evaluation of selected Citrus spp. and
relatives for susceptibility to root injury by Diaprepes abbreviatus larvae (Co-
leoptera: Curculionidae). Florida Entomol. 68: 222-223.
GRAY, A. I., AND P. G. WATERMAN. 1978. Coumarins in the Rutaceae. Phytochemistry
17: 845-864.
MAYER, R. T., J. P. SHAPIRO, E. BERDIS, C. J. HEARN, T. G. MCCOLLUM, R. E. Mc-
DONALD, AND H. DOOSTDAR. 1995. Citrus rootstock responses to herbivory by
larvae of the sugarcane rootstock borer weevil (Diaprepes abbreviatus). Physi-
ologia Plantarum 94: 164-173.
MCCOLLUM, T. G., H. DOOSTDAR, R. E. MCDONALD, J. P. SHAPIRO, R. T. MAYER, L. W.
TIMMER, AND R. M. SONODA. 1995. Exploitation of plant pathogenesis-related
proteins for enhanced pest resistance in citrus. Proc. Florida State Hort. Soc.
108: 88-92.
NORDBY, H. E., AND S. NAGY. 1981. Chemotaxonomic study of neutral coumarins in
roots of Citrus and Poncirus by thin-layer, gas-liquid and high-performance liq-
uid chromatographic analyses. J. Chromatogr. 207: 21-28.
PANDA, N., AND G. S. KHUSH. 1995. Host plant resistance to insects, 431 pp., CAB In-
ternational, Wallingford, UK.
SHAPIRO, J. P. 1991. Phytochemicals at the plant-insect interface. Arch. Insect Bio-
chem. Physiol. 17: 191-200.
SHAPIRO, J. P. 1992. Assimilation, transport, and distribution in insects of molecules
from natural and artificial diets pp. 63-76 in T. E. Anderson and N. C. Leppla
[eds.], Advances in Insect Rearing for Research and Pest Management. West-
view Press, Boulder, Colorado.


December, 1997

















Shapiro et al.: Citrus Root Resistance Bioassay 477

SHAPIRO, J. P., AND T. R. GOTTWALD. 1995. Resistance of eight cultivars of citrus root-
stock to a larval root weevil, Diaprepes abbreviatus L. (Coleoptera: Curculion-
idae). J. Econ. Entomol. 88: 148-154.
SHAPIRO, J. P., R. T. MAYER, AND W. J. SCHROEDER 1988. Absorption and transport
of natural and synthetic toxins mediated by hemolymph proteins, pp. 997-1005
in F. Sehnal, A. Zabza and D. L. Denlinger [eds.], Endocrinological Frontiers in
Physiological Insect Ecology. Wroclaw Technical University, Wroclaw, Poland.
SMITH, C. M. 1989. Plant resistance to insects: A fundamental approach to insect pest
management, 464 pp., John Wiley & Sons, New York.
STATSOFT, INC. 1995. STATISTICA, release 5. StatSoft, Inc., Tulsa, OK.


4444444444444444444444444444444444444444444444444444
















Mitchell et al.: Effect of Parasitoids on Diamondback Moth 477


DIAMONDBACK MOTH (LEPIDOPTERA: PLUTELLIDAE):
PARASITISM BY COTESIA PLUTELLAE (HYMENOPTERA:
BRACONIDAE) IN CABBAGE

E. R. MITCHELL, F. C. TINGLE, R. C. NAVASERO-WARD AND M. KEHAT'
Center for Medical, Agricultural and Veterinary Entomology
Agricultural Research Service, U.S. Department of Agriculture
Gainesville, Florida 32608

'Agro. Res. Organization, The Volcani Center, P.O. B. 6, Bet-Dagan 50250, ISRAEL

ABSTRACT

Cotesia plutellae Kurdjumov was evaluated as a potential biological control agent
for diamondback moth, Plutella xylostella (Linnaeus), in cabbage in spring 1993 and
1994. The parasitoids were reared in a commercial insectary in Texas, delivered over-
night via air express, and released 24-48 h after receipt in cabbage fields in Northeast
Florida. In 1993, only adult parasitoids were released, but adults and cocoons were re-
leased in 1994. The numbers of C. plutellae released ranged from 456 per ha per wk
in 1993 to 1,334 per ha per wk in 1994. Four consecutive releases were made each year
beginning in early February. Parasitism of diamondback moth larvae by C. plutellae
ranged from 3.6 to 10.9%, and the level of parasitism was related to the total numbers
of parasitoids released. C. plutellae parasitoids were complimentary to the naturally
occurring parasitoid Diadegma insulare (Cresson), and the combined mean seasonal
parasitism of diamondback moth exceeded 34% in some fields. There was no evidence
that C. plutellae became established in the general area although > 124,000 parasi-
toids were released over the 2-year test period.

Key Words: Plutella xylostella, biological control, integrated pest management, Dia-
degma insulare

RESUME

Cotesia plutellae Kurdjumov fue evaluada como agent potential de control biolo-
gico para Plutella xylostella (Linnaeus) en la col, en las primaveras de 1993 y 1994. El
parasitoide fue criado en un insectario commercial en Texas, enviado por correo expreso,
y liberado a las 24-48 horas de recibido en campos de col del nordeste de la Florida. En

















Florida Entomologist 80(4)


1993 solamente fueron liberados parasitoides adults, pero en 1994 fueron liberados
adults y capullos. Los numeros de C.plutellae liberados estuvieron en el rango de los
456 por ha por semana en 1993, a los 1,334 por ha por semana en 1994. Cuatro libe-
raciones consecutivas fueron hechas cada aio comenzando a principios de febrero. El
parasitismo de P. xylostella porP. plutellae estuvo en el rango de 3.6 a 10.9%, y el nivel
de parasitismo estuvo relacionado con los numerous de parasitoides liberados. Los pa-
rasitoides fueron complementarios del parasitoide natural Diadegma insulare (Cres-
son), y el parasitismo combinado estacional de P. xylostella excedi6 el 34% en algunos
campos. No hubo evidencia que C. plutellae llegara a establecerse en el area a pesar
de que mas de 124,000 parasitoides fueron liberados durante los dos afios del period
de prueba.





The diamondback moth, Plutella xylostella (Linnaeus), is a serious pest of crucif-
erous crops throughout the world. In tropical and subtropical areas, crucifer produc-
tion has been seriously affected in recent years by populations that have developed
resistance to a wide range of insecticides (Talekar & Shelton 1993). Until the mid-
1980s in North America, diamondback moth was considered a minor pest, possibly be-
cause biological control by natural enemies maintained populations below economi-
cally damaging levels. In the United States, increases in the pest have been most
severe in southern states, especially Florida, Georgia, North Carolina, and Texas. In-
secticide resistance appears to be the most important cause (Leibee & Savage 1992,
Leibee et al. 1995). Bacillus thuringensis-based pesticides and growth regulators are
effective control agents with minimal environmental impact, provided resistance can
be avoided (Shelton et al. 1993).
Combining pest control tactics may be the best approach for handling pesticide re-
sistance in diamondback moth. Biever et al. (1994) described the evolution and imple-
mentation of a biological control-integrated pest management system for lepidopterous
pests of crucifers developed over a period of 24 years. Basically the program consists of
three elements: regular scouting of the crop to estimate plant damage and larval infes-
tations; application of pesticides only when needed with reliance upon Bacillus thur-
inginesis-based insecticides; and preservation of natural enemies combined with
periodic releases of parasitoids.
Cotesia plutellae Kurdjumov frequently is mentioned as a possible biological con-
trol agent for diamondback moth (Talekar & Shelton 1993). There have been sporadic
releases of this parasitoid in Florida (Frank & McCoy 1993), but little data are avail-
able on its recovery or efficacy. This study reports on the recovery of C. plutellae in
commercial cabbage fields subjected to conventional pest control practices following
inoculative releases of this parasitoid. Data also were collected on the seasonal occur-
rence and effectiveness of Diadegma insulare (Cresson), a naturally-occurring larval
parasitoid of diamondback moth. The trials were conducted near Bunnell, Flagler
County, Florida during the winter-spring cabbage growing seasons of 1993 and 1994.

MATERIALS AND METHODS

Parasitoid Source

Cotesia plutellae parasitoids used in this study were purchased from Biofac, Inc.,
Mathis, TX. The parasitoids were shipped overnight via air express to Gainesville, FL.
Adult parasitoids were shipped in 1993 and cocoons were shipped in 1994. The adults


December, 1997


















Mitchell et al.: Effect of Parasitoids on Diamondback Moth 479

(about 250 ea) were packaged in small cardboard cylinders (12.7 cm long x 3.81 cm
diam) capped at both ends. The cylinders were wrapped with old newsprint and bun-
dled in a Styrofoam chest containing packets of ice enclosed in plastic bags (also
wrapped with old newsprint) to keep the insects immobile while in transit.
In 1994, cocoons on paper towels (about 1,000 ea) were enclosed in plastic bags,
wrapped with old newsprint and inserted in Styrofoam containers for shipping as de-
scribed for adult parasitoids. Upon arrival, the cocoons were subdivided as required
to meet test requirements. Adult parasitoids released in 1994 were received as co-
coons and allowed to emerge in the laboratory. The parasitoids were fed a 10% honey-
sugar water solution while in confinement.
Adult parasitoids released in 1993 were placed in the field within 48 h after ship-
ment from the insectary in Texas. Adult parasitoids released in 1994 were shipped to
Florida as cocoons, allowed to emerge in the laboratory, and placed in the field within
24 h after emergence.


Pesticide Applications

Grower cooperators applied pesticides to the cabbage crop at their discretion.


1993 Field Trials

Parasitoid Release-Adult parasitoids were released in two cabbage fields in 1993
(Fig. 1). Release area 1 (field 1) was 12.1 ha in size and part of a large cabbage field to-


Johnston

C.,.32


L T


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North


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Cotesia plutellae per hectare


1993
1 494 adults
2 0 control
3 494 adults
4 0 control


1994
A 1,482 cocoons
B 741 adults
C 741 cooons
D 0 control


Fig. 1. Schematic of experimental site. Inset shows arrangement of parasitoid re-
lease stations and sampling sites (1994 only) in fields A, C, and D. Field B had six re-
lease stations and sampling sites (2 rows of 3 each). Bunnell, Flagler County, FL.


r

















Florida Entomologist 80(4)


talking 24.2 ha, the western half of which was designated as a control area (field 2). The
second release area (field 3, 8.1 ha) was located about 1.3 km west of release area 1
(Fig. 1). The second control area (field 4,4.0 ha) joined field 3 along the southeast edge.
The test fields were located in agricultural areas devoted to the production of cab-
bage and potatoes. Field 1 was bordered on the eastern edge by wooded swamp, the
south by potato fields, the west by the control (field 2), and the north by potato fields.
Control field 2 was bordered on the south and north by potatoes and on the west by
open pasture land. Field 3 (release area 2) was bordered on the north by wooded
swamp, the east and west by cabbage in various stages of maturity, and the south by
cabbage (field 4) and fallow crop land.
Cotesia plutellae were released in fields 1 and 3 at a target rate of 494 adults per
ha for four consecutive weeks beginning 24 February. This release rate was based
upon the recommendation of D. Biever (pers. comm.) from his experiences in develop-
ing an integrated management system for pests of crucifers over a 24-year period
(Biever et al. 1994). Estimates of actual release rates were made by examining the re-
lease containers for dead parasitoids. The sex ratio was approximately 1:1 as deter-
mined from examination of representative samples of adults before they were
released. The parasitoids were transferred from shipping cylinders into 0.24 liter pa-
per cartons equipped with screened lids for release. A cotton ball in a small plastic cup
saturated with 10% honey-sugar water solution provided a food source for the parasi-
toids. The cartons were placed in the field at the base of cabbage plants and opened to
allow the parasitoids to escape. Thirty release sites were established in field 1 (12.1
ha) and 20 were established in field 3 (8.1 ha). The release sites were spaced equidis-
tant throughout the field in either a 5 x 6 (field 1) or 4 x 5 grid (field 3). Thus, each re-
lease site was near the center of a 0.4 ha block of cabbage.
Sampling procedure-Each parasitoid release field and correspondent control field
was systematically sampled weekly throughout the growing season for evidence of C.
plutellae activity. Each field was divided into four sections nearly equal in size across
its width; each section then was subdivided into thirds throughout the length of the
field. Timed searches of cabbage plants selected at random were conducted in each of
the 12 sections (10 min ea). Thus, each field was scouted for diamondback moth larvae
and cocoons or parasitoids for a total of 2 h per wk. The larvae and cocoons collected
were returned to the laboratory and held at ambient conditions of 25 2 C, 70-80%
RH and under continuous fluorescent lighting for emergence of adult moths or para-
sitoids. The larvae were held individually in 29.6 ml plastic cups on a modified pinto
bean diet (Guy et al. 1985) until emergence of adult moths or parasitoids, or until the
larvae died. Diamondback moth pupae and parasitoid cocoons were held separately in
0.24 ml plastic cups until emergence of adults or death.

1994 Field Trials

The location of cabbage fields used in 1994 are shown in Fig. 1. Fields A and D were
12.1 ha in size, field C was 10.5 ha, and field B was 4.8 ha. Field D was the same field
used as a control area (i.e., field 2) in 1993. Field A was bordered on the south and north
by cabbage, the east by wooded swamp, and the west by a drainage ditch, unpaved
county road, and open pasture land. Field B was bordered on the north and east by ma-
turing cabbage fields ready for harvest or that had been harvested but the plant residue
had not been destroyed; potato fields bordered the field on the west; and the south side
was bordered by a state highway across which was maturing or harvested cabbage fields.
Parasitoid release-Parasitoids were released either as cocoons or adults. Cocoons
were released in fields A and C at a target rate of 1,482 and 741 per ha, respectively,
and adult parasitoids were released in field B at a target rate of 741 per ha. Estimates


December, 1997

















Mitchell et al.: Effect of Parasitoids on Diamondback Moth 481

of actual release rates were established later by examining the release containers for
dead cocoons or adults a few days after each release. Four releases of adult parasitoids
or cocoons were made every two weeks beginning 06 February. The sex ratio as deter-
mined from cocoons held in the laboratory for emergence was about 1:1. Release
cages, measuring 60 cm long x 38 cm wide x 30 cm high, were partially covered on the
sides with 0.32-cm mesh hardware cloth to allow adult parasitoids to exit (Fig. 2). A
cotton ball in a plastic cup was saturated with 10% honey-sugar water solution to pro-
vide a food source for the adults upon emergence.
Turlings et al.(1989, 1990a and b) conditioned C. marginiventris (Cresson) females
to search for larval hosts after exposure to odors from plants damaged by beet army-
worm [(Spodoptera exigua (Hibner)] larvae. They also reported that C. marginiven-
tris females were significantly more responsive to the odors after a brief contact
experience with host-damaged leaves contaminated with host by-products; but actual
encounters with hosts were not required to improve subsequent responses to host-re-
lated odors. We obtained similar results with C. plutellae females in flight tunnel as-
says after exposure to cabbage plants damaged by diamondback moth larvae
(unpublished). Thus, cabbage plants bearing diamondback moth larvae were placed
inside each release cage to condition adult C. plutellae parasitoids to search for hosts
upon exiting the release station.
The release cages (9 in fields A and C, 6 in field B) were spaced equidistance apart
throughout each field (Fig. 1). The cages were mounted on metal conduit poles in
drainage ditches so that the bottom of the release station was about 0.5 m above the
top of the cabbage plants. Cocoons, still attached to paper toweling, were placed in pa-
per cups and set in the cages next to a potted cabbage plant with feeding diamondback
larvae. Adult parasitoids in 0.24 liter paper cups were chilled in a Styrofoam chest for
transport to the field. A paper cup containing the requisite number of parasitoids was
placed in the release cage adjacent to a potted cabbage plant with feeding diamond-
back moth larvae.
Sampling procedure-The fields were sampled weekly for host larvae and pupae
and cocoons of parasitoids, namely C. plutellae and D. insulare. Nine sites were sam-
pled in fields A, C, and D and six in field B (Fig. 1, see inset). The sample sites were
about equally spaced throughout each field. Initially, all cabbage plants (mean = 65)
on 15.2 m of row were examined for larvae, pupae, and cocoons; but as the season pro-
gressed and the plants grew in size, the distance was decreased to 3 m per site (mean
= 13 plants) the week of harvest.
The diamondback larvae collected were brought into the laboratory where most
were dissected to determine if they were parasitized (Day 1994). Some larvae were
held on artificial diet as previously described for emergence of moths or adult parasi-
toids to confirm identifications determined by dissections. Diamondback moth pupae
and parasitoid cocoons also were held separately in 0.24 ml plastic cups until they
emerged or died.
Statistical analysis-Parasitism of diamondback moth larvae in 1993 was analyzed
using unpaired t-tests (Littell et al. 1991). The analyzes compared the combined ef-
fects of field and treatment, i.e., field 1 + parasitoid releases vs. field 2 + no parasitoid
release; and field 3 + parasitoid releases vs. field 4 + no parasitoid release (Fig. 1). In
the 1994 trial, a 1-way analysis of variance (ANOVA) was used with fields as the fac-
tor and mean percent parasitism or number of diamondback moth larvae per plant as
the response variable. As in the 1993 trial, the analyzes compared the combined ef-
fects of field and parasitoid releases (A, B, and C) or field and no parasitoid release (D)
(Fig. 1). Differences indicated by significant ANOVA were compared using the Waller-
Duncan K-ratio t-test (Littell et al. 1991).
















Florida Entomologist 80(4)


Fig. 2. Release station for Cotesia plutellae parasitoids. Cocoons or adult parasi-
toids were placed in open paper cups and set in the release cage next to a potted cab-
bage plant infested with diamondback moth larvae.


December, 1997

















Mitchell et al.: Effect of Parasitoids on Diamondback Moth 483

RESULTS

1993 Release

The number of parasitoids targeted for release was 494 per ha. Examination of the
release cartons within 24 h after each release period revealed that only 7.5% of the
parasitoids had died. Thus, the actual number of parasitoids released was about 456
per ha. Over the release period, an estimated total of 18,500 C. plutellae adults were
released in fields 1 and 3 (Fig. 1).
A total of 2,802 diamondback moth forms (1,415 larvae and 1,387 pupae) were col-
lected in the four test fields which yielded 725 parasitoids and 1,246 diamondback
moth adults. The remainder died in the holding cups before pupation or eclosion as
adults.
Although low, percent parasitism (mean s.e.) of host larvae by C. plutellae was
significantly greater (unpaired t-test, Littell et al. 1991) in release fields 1 and 3 than
in the correspondent controls, fields 2 and 4 (Fig. 1): field 1 = 0.76 0.29 vs. field 2 =
0, t = 2.315, 21 d.f., P = 0.031; and field 3 = 2.14 + 0.76 vs. field 4 = 0, t = 2.384, 17 d.f,
P = 0.029.
There also was no significant difference in the percentage of diamondback larvae
parasitized by the naturally-occurring D.insulare in the parasitoid release fields (1
and 3) versus the control fields (2 and 4): field 1 = 28.51 + 3.27 vs. field 2 = 25.86 3.14;
t = 0.572, 21 d.f., P = 0.573; and field 3 = 24.65 5.42 vs. field 4 = 22.26 4.68; t =
0.316, 17 d.f., P = 0.756. Mean parasitism of host larvae by D. insulare in the four
fields was 25.68 + 2.05%.

1994 Release

Examination of the cartons used to release cocoons and adults revealed that > 90%
of the parasitoids had survived and escaped the release cage. Thus, the targeted re-
leases of 1,482 and 741 cocoons or adults per ha actually was about 1,334 and 667 co-
coons or adults, respectively. Over the release period, an estimated total of 105,840 C.
plutellae parasitoids were released in fields A, B, and C.
A total of 3,310 diamondback moth forms (2,004 larvae and 1,306 pupae) were col-
lected in all fields in 1994. A total of 653 D. insulare and 162 C. plutellae also were re-
covered, most all of which were identified from dissections of diamondback moth
larvae (Day 1994). Specimens of a few other species also were noted, but they were not
identified.
The seasonal occurrence of diamondback larval populations in fields A-D and the
level of larval parasitism in each are shown in Fig. 3. There was no significant differ-
ence in the mean ( s.e.) number of diamondback moth larvae per cabbage plant in
fields A (0.035 0.010), B (0.016 0.006), C (0.030 + 0.009), and D (0.030 + 0.005)
when averaged over the season. These results were not surprising as the grower co-
operators sprayed their cabbage as frequently as deemed necessary to protect the crop
from economic damage.
As expected, the highest mean level of parasitism of diamondback larvae by C. plu-
tellae was recorded in field A (10.9%) where the largest number of cocoons were re-
leased. However, mean larval parasitism by C. plutellae in this field was not
significantly different from field C (5.4%) where about 50% fewer cocoons were re-
leased (Table 1). Parasitism of diamondback larvae by C. plutellae in field B (target of
741 adults per release) and D (no parasitoids released) was 3.6 1.5% and 0%, respec-
tively. The weekly levels of parasitism by C. plutellae in each field closely paralleled
the release of the parasitoid (Fig. 3). After parasitoid releases were terminated, par-

















Florida Entomologist 80(4)


1.482 Cotesia cocoons Field A


741 Cotesia cocoons Field C
RS R S R S SR S S s


A'


Control Field D


S S


a s a


I I I........I


1/25 2/01 2/08 2/15 2/22 3/01 3/08 3/15 3/22 3/29 4105 4112


% parasitism
Cotesia


-- DBM larvae
per plant


4/19 4/26


E % parasitism
Diadegma


Fig. 3. Seasonal incidence of diamondback moth larval populations and parasitism
by Cotesia plutellae and Diadegma insulare in cabbage. R = date parasitoids were re-
leased; S = date field was sprayed with insecticide. Bunnell, FL. 1994.


asitism by C. plutellae in fields A, B, and C became progressively less through the re-
mainder of the season.
Mean parasitism over the cabbage-growing season by the naturally-occurring par-
asitoid D. insulare was highest in fields A (29.4%) and B (31.3%); intermediate in field
D where no C. plutellae were released (20.7%); and lowest in field C (8.6%) (Fig. 3 and
Table 1). Mean total parasitism attributed to both C. plutellae and D. insulare also
was highest in fields A (40.3%) and B (34.9%). Mean total parasitism of diamondback
larvae in fields C and D was 13.7% and 20.7%, respectively.
There was no evidence that C. plutellae survived and became established in the
test area following releases made in 1993 or 1994. Growers typically plant the same


- 0.20
- 0.16
- 0.12
-0.08
- 0.04
-0.00


-0.20
- 0.16
-0.12
- 0.08
-0.04
- 0.00


. .. . . I . . I . . I . .. P . . - .


. . . i


December, 1997


I


' ' ~ ~

















Mitchell et al.: Effect of Parasitoids on Diamondback Moth 485

fields in cabbage year after year. Thus, we were able to examine the fields in which
parasitoids were released in 1993 and 1994 to determine if there was carryover of C.
plutellae into the following spring cabbage growing season. No C. plutellae were re-
covered in field D in spring 1994 although C. plutellae were recovered in this area in
spring 1993 following release of adult parasitoids in field 1 (Fig. 1). In spring 1995,
cabbage in field A (where parasitoids were released in spring 1994, Fig. 1) and field D
were sampled intensely at weekly intervals from February through April and not a
single C. plutellae parasitoid was recovered. Cabbage in field C, where C. plutellae co-
coons were released in spring 1994 (Fig. 1) and parasitism of host larvae averaged
5.4% for the season (Table 1), also was sampled intensively at weekly intervals
throughout the winter-spring 1995 cabbage growing season. As in fields A and D, no
C. plutellae were recovered.
In fall 1992, we released a total of 24,981 C. plutellae adults in two cabbage fields
totaling 12 ha near Zellwood in Central Florida (unpublished). Three releases of about
equal numbers of parasitoids (target number per ha = 625) were released at weekly
intervals beginning 16 November. These parasitoids also were purchased from Biofac,
shipped overnight via air express as described, and released the following morning di-
rectly from shipping tubes (250 adults ea) in which they were received. The tubes
were evenly spaced throughout each field and placed beneath cabbage leaves for
shade. As in the 1993 and 1994 trials, the fields used in 1992 were sprayed heavily,


TABLE 1. RELATIONSHIP BETWEEN RELEASES OF COTESIA PLUTELLAE AND THE NATU-
RALLY-OCCURRING PARASITOID DIADEGMA INSULARE ON PARASITISM OF DIA-
MONDBACK MOTH LARVAE IN CABBAGE IN 1994. BUNNELL, FL.

Field Cotesia Released' Stage Number/ha Mean % Parasitism ( s.e.)2

Parasitism by Cotesia (P = 0.0003)
A Cocoons 1482 10.9 2.9a
B Adults 741 3.6 1.5b
C Cocoons 741 5.4+ 1.7ab
D None 0 Oc

Parasitism by Diadegma (P = 0.0023)
A Cocoons 1482 29.4 4.4a
B Adults 741 31.3 7.4a
C Cocoons 741 8.3 3.4b
D None 0 20.6 4.5a

Total parasitism (P = 0.0013)
A Cocoons 1482 40.3 3.8a
B Adults 741 34.9 7.0ab
C Cocoons 741 13.7 3.6c
D None 0 20.7 4.5bc

'The targeted number of parasitoids per release is shown. The actual numbers released, based upon subse-
quent mortality counts, was about 90% of total shown. Parasitoid releases were made at 2-week intervals on four
different occasions starting 06 February.
Means in the same group with different letters are significantly different, Waller-Duncan K-Ratio T test (P-
values are shown in parentheses).

















Florida Entomologist 80(4)


TABLE 2. PESTICIDES USED FOR INSECT CONTROL IN CABBAGE FIELDS WHERE THE PARASI-
TOID COTESIA PLUTELLA WAS RELEASED IN 1994. BUNNELL, FL.

Date Material Rate/ha Mortality Index'


Field A 1,482 cocoons/ha
Monitor 0.71 liter
Xentari 0.24 liter
Monitor 0.71 liter
Monitor 0.71 liter
Phosdrin 0.71 liter


Field B
Monitor 4
Lannate LV
Lannate LV
Dipel 2X
Lannate LV
Thiodan
Dipel
Lannate LV
Xentari


741 cocoons/ha
0.47 liter
0.47 liter
0.47 liter
0.45 kg
0.47 liter
0.95 liter
0.45 kg
0.47 liter
0.23 kg


22-Feb


10-Mar
24-Mar
01-Apr



03-Feb
08-Mar
18-Mar


28-Mar
02-Apr


12-Apr




07-Feb
21-Feb


09-Mar
16-Mar
23-Mar
31-Mar


05-Apr


10-Feb


08-Mar


21-Mar
08-Apr


Field C 741 cocoons/ha
Xentari 0.34 kg
Monitor 0.71 liter
Dipel 0.45 kg
Dipel 0.45 kg
Agree 0.45 kg
Phosdrin 0.95 liter
Lannate LV 0.71 liter
Xentari 0.23 kg
Phosdrin 0.71 liter

Field D control
Monitor 0.71 liter
Agree 0.34 kg
Phosdrin 0.83 liter
Agree 0.23 kg
Asana 0.24 liter
Agree 0.23 kg
Dipel 0.23 kg


'Mortality index for Cotesia adults: 1 = harmless (50%); 2 = slightly harmful (50-79%); 3 = moderately harm-
ful; 4 = harmful (> 99%); ND = no data. All materials sprayed were relatively harmless to Cotesia cocoons. (Kao
and Tzeng 1992).


December, 1997

















Mitchell et al.: Effect of Parasitoids on Diamondback Moth 487

TABLE 2. (CONTINUED)PESTICIDES USED FOR INSECT CONTROL IN CABBAGE FIELDS WHERE
THE PARASITOID COTESIA PLUTELLA WAS RELEASED IN 1994. BUNNELL, FL.

Date Material Rate/ha Mortality Index'

Lannate 0.95 liter 4
14-Apr Asana 0.24 liter 1
22-Apr Asana 0.24 liter 1

Mortality index for Cotesia adults: 1 = harmless (50%); 2 = slightly harmful (50-79%); 3 = moderately harm-
ful; 4 = harmful (> 99%); ND = no data. All materials sprayed were relatively harmless to Cotesia cocoons. (Kao
and Tzeng 1992).


and diamondback larval populations were low. Total parasitism of diamondback by C.
plutellae was < 0.1%; and no C. plutellae were recovered in these fields in spring or fall
1993.


DISCUSSION

Numerous attempts have been made to introduce C. plutellae into different areas
of the world with mixed results (Talekar & Shelton 1993). In the western hemisphere,
C. plutellae reportedly flourished after introductions into Barbados and Jamaica, and
it is credited with affecting significant control of diamondback moths on these and
other Caribbean islands (Alam 1992). However, attempts to introduce C. plutellae into
Honduras, Belize, Costa Rica, and Florida (USA) have not resulted in suppression of
diamondback moths (Andrews et al. 1992, Frank & McCoy 1993).
Explanations for establishment of C. plutellae in some areas and not others are not
readily apparent. Cotesia plutellae are numerically responsive to increasing popula-
tions of diamondback moths (Ooi 1992, Rowell et al. 1992) and thrive in environments
that have not been sprayed with insecticides (Alam 1992). In Florida, cabbage and
other cole crops are treated regularly with insecticides to keep pest populations low
and prevent damage by diamondback moth larvae (McLaughlin & Mitchell 1993,
McLaughlin et al. 1994, Leibee et al. 1995, and Table 2).
In conclusion, C. plutellae reproduced in the fields where released, did not survive
more than one year, and probably was much less important than the naturally-occur-
ring parasitoid D.insulare. There also was no evidence that C. plutellae dispersed to
other fields nearby. However, in a subsequent study Mitchell (unpublished) found that
C. plutellae parasitoids spread down wind from the release area but parasitism of di-
amondback moth larvae on sentinel cabbage or collard plants decreased as the dis-
tance from the release area increased up to 800 m.


ACKNOWLEDGMENTS

We appreciate the help ofW. Copeland and J. Rye in sampling the fields and pre-
paring the release sites; B. Monroe for constructing the parasitoid release cages; J.
Gillet for checking larvae for evidence of parasitism; and J. Leach for compiling the
data and preparing the graphics. We extend a special thanks to V. Chew for helpful
suggestions on analysis of the data. This article reports the results of research only.
Mention of a proprietary product does not constitute an endorsement or the recom-
mendation for its use by USDA.

















Florida Entomologist 80(4)


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ALAM, M. M. 1992. Diamondback moth and its natural enemies in Jamaica and some
other Caribbean islands, pp. 233-243 in N. S. Talekar [ed.], Diamondback Moth
and Other Cruciferous Pests: Proceedings of the Second International Work-
shop. Shunhua, Taiwan. Asian Vegetable Research and Development Center.
ANDREWS, K L., R. J. SANCHEZ, AND R. D. CAVE. 1992. Management of diamondback
moth in Central America, pp. 487-497 in N. S. Talekar [ed.], Diamondback
Moth and Other Cruciferous Pests: Proceedings of the Second International
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BIEVER, K D., D. L. HOSTETTER, AND J. R. KERN. 1994. Evolution and implementation
of a biological control-IPM system for crucifers: 24-year case history. American
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DAY, W. H. 1994. Estimating mortality caused by parasites and diseases of insects:
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550.
FRANK, J. H., AND E. D. MCCOY. 1993. The introduction of insects into Florida. Florida
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GuY, R. H., N. C. LEPPLA, J. R. RYE, C. W. GREEN, S. L. BARRETTE, AND K. A. HOLLIEN.
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of Insect Rearing, Vol. 2. Elsevier, Amsterdam.
KAO, S.-S., AND C.-C. TZENG. 1992. Toxicity of Insecticides to Cotesia plutella, a para-
sitoid of diamondback moth, pp. 287-296 in N. S. Talekar [ed.], Diamondback
Moth and Other Cruciferous Pests: Proceedings of the Second International
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LEIBEE, G. L., AND K. E. SAVAGE. 1992. Evaluation of selected insecticides for control
of diamondback moth and cabbage looper in central Florida with observations
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591.
LEIBEE, G. L., R. K. JANSSON, G. NUESSLY, AND J. L. TAYLOR 1995. Efficacy of ema-
mectin benzoate and Bacillus thuringinesis at controlling diamondback moth
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field. J. Econ. Entomol. 86: 697-705.
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Florida Entomologist 80(4)


December, 1997


THE "MUSEO DE ENTOMOLOGIA Y BIODIVERSIDAD
TROPICAL" OF THE AGRICULTURAL EXPERIMENT STATION,
UNIVERSITY OF PUERTO RICO

R. A. FRANQUI, J. A. SANTIAGO-BLAY2, S. MEDINA GAUD' and E. ABREU3
'Department of Crop Protection, Agricultural Experiment Station
University of Puerto Rico, Rio Piedras, Puerto Rico 00928

'Department of Ecology and Evolution, 1101 East 57th Street
The University of Chicago, Chicago, IL 60637

3Department of Crop Protection, Agricultural Experiment Station
University of Puerto Rico, Isabela, Puerto Rico 00662

HISTORY OF THE COLLECTION
The collection of the Museo de Entomologia y Biodiversidad Tropical (formerly the
Entomology Museum) at the Agricultural Experiment Station (AES) of the University
of Puerto Rico is the largest depository of insects in Puerto Rico (Santiago-Blay et al.
in prep.). The collection harbors more than 200,000 specimens, mostly from Puerto
Rico, in its main collection at Rio Piedras (not to be confused with the Rio Piedras
Campus of the University of Puerto Rico that also houses significant biological collec-
tions) and some additional holdings in the Isabela (approximately 5,000 insects of ag-
ricultural importance and 1,200 identified Acari).
The collection was started in 1910 by D. L. Van Dine, W. V. Tower, E. G. Smyth, C.
E. Hood, and G. N. Wolcott, all entomologists working with sugarcane in Puerto Rico
(Cook and Otero 1937). Following the successful control of insect pests in major com-
modities in the continental United States, great emphasis was placed in solving prac-
tical agricultural problems caused by insects, such as sugarcane white grubs,
Diaprepes abbreviatus (L.) (Coleoptera: Curculionidae), and Phyllophaga spp. (Co-
leoptera: Scarabeidae), in the Island. Some examples of biological control that influ-
enced research activities in Puerto Rican agricultural entomology were: 1) the cottony
cushion scale (Icerya purchase Mask., Homoptera: Margarodidae) in California or-
anges controlled by Rhodolia cardinalis Mulsant (Coleoptera: Coccinellidae) and
Cryptochaetum iceryae Williston (Diptera: Cryptochaetidae) in the late 1880s), and 2)
the sugarcane leafhopper (Perkinsiella saccharicida Kirkaldy, Homoptera: Cicadel-
lidae) in Hawaii controlled by several parasites, of which Paranagrus optabilis Per-
kins (Hymenoptera: Mymaridae) was perhaps the most important (Perkins and
Kirkaldy 1907). These are interesting cases in the history and interactions between
science, agribusiness, government, and the general public in Puerto Rico.
Since 1910, the main collection has been housed in several locations within the Bi-
ology Building at the AES in Rio Piedras, expanded, and kept as a research tool. One
of the unique aspects of this collection is the detailed accession number catalog that
cross-references about 85% of the pinned specimens with additional biological data.
The efforts of dedicated researchers, such as George N. Wolcott, Luis F. Martorell, Jos6
Garcia Tuduri, Silverio Medina Gaud, Niilo Virkki, and many others contributed to
the collection's maintenance and development. The collection has had some teaching
functions and has been used to identify insects for the public.
Since November 1996, the collection has been located on the east wing of the Edi-
ficio de Agronomia (Agronomy Building) in front of the Biology Building, and it was of-
ficially inaugurated on May 9, 1997. In addition to its space devoted to research

















Scientific Notes


TABLE 1. APPROXIMATE NUMBER OF HOLDINGS OF HEXAPODA IN THE MUSEO DE ENTO-
MOLOGIA Y BIODIVERSIDAD TROPICAL AT THE AGRICULTURAL EXPERIMENT
STATION OF THE UNIVERSITY OF PUERTO RICO.

Numbers and Numbers and
Taxon remarks Taxon remarks

Protura 136 Psocoptera 629
Collembola 38 Phiraptera 2531
Diplura 67 Hemiptera 7,647
Thysanura 29 Homoptera 10,0632
Ephemeroptera 793 Thysanoptera 6,8993
Odonata 2,456 Neuroptera 1,267
Phasmida 144 Coleoptera 12,6824
Orthoptera 729 Strepsiptera 10
Mantodea 46 Siphonaptera 317
Blattaria 1,422 Diptera 10,7676
Isoptera 2,6226 Trichoptera 2,258
Dermaptera 189 Lepidoptera 10,775
Embiidina 10 Hymenoptera 9,389
Zoraptera 81 Total 81,718

Other assorted specimens, in liquid preservatives 137,000

TOTAL 218,718

'Including 171 identified specimens from Puerto Rico on slides.
'Including 891 identified specimens of aphids from Puerto Rico on slides.
'Including 1,453 identified specimens from Puerto Rico on slides.
'Does not include significant numbers of immature Scarabaeidae and Curculionidae in liquid preservatives.
'Including 100 identifiedAedes larvae from Puerto Rico on slides. However, this number does not include sig-
nificant holdings ofAnastrepha immatures in liquid preservatives.
"Does not include significant holdings of specimens in liquid preservatives.


collections, the "Museo" has beautiful, new exhibits for the public. The stream of vis-
itors and local media coverage have been overwhelming. The collection has been for-
mally recognized by the administration of the Agricultural Experiment Station, and
in its new location the collection occupies 336.5 square meters; an additional 119.7
square meters were recently transferred to the "Museo" and they are being developed.


HOLDINGS

The Museo de Entomologia y Biodiversidad Tropical holds approximately 220,000
organisms representing the 27 orders of insects known to occur in Puerto Rico (Borror
et al. 1989 classification; Mycrocoryphia, Grylloblattaria, Plecoptera, and Mecoptera
have not been reported for the island). Major collections include those of Thysan-
optera, Aphididae (Homoptera), Trichoptera (recently donated by Dr. Oliver Flint, Na-
tional Museum of Natural History, Washington, D. C.), Muscidae (Diptera), and an
assorted collection pertaining to medical and veterinary entomology. The collection
holds a modest number of mollusks, some Diplopoda, Chilopoda, as well as arachnids,

















492 Florida Entomologist 80(4) December, 1997

including spiders and scorpions. Details of the holdings for the Hexapoda are summa-
rized in Table 1.


LOAN POLICY

Currently, loans are made for three years and are renewable following written no-
tification. Loan requests should be addressed to Dr. R. A. Franqui. We request authors
to forward reprints of any publications resulting from the use of our material. Also, we
are pursuing the return of material on indefinite, or unauthorized loans.

REFERENCES CITED

BORROR, D. J., C. A. TRIPLEHORN, AND N. F. JOHNSON. 1989. An introduction to the
study of insects, 6th ed. Philadelphia, PA. Saunders College Publ. 875 pp.
COOK, M. T., AND J. J. OTERO. 1937. History of the first quarter of a century of the Ag-
ricultural Experiment Station at Rio Piedras, Puerto Rico. Bull. 44. Agric. Exp.
Stn. 123 pp.
PERKINS, R. L. C., AND G. W. KIRKALDY. 1907. Parasites of leaf-hoppers. Report of
work of the Experiment Station of Hawaiian Sugar Planters' Association. Bull.
4. 66 pp.
















Book Reviews


BOOK REVIEWS

DELOYA LOPEZ, A. C. (ed). 1997. La Sociedad Mexicana de Entomologia: pasado,
present y future. Sociedad Mexicana de Entomologia; Xalapa, M6xico. Paperback, v
+ 202 p. ISBN 968-7801-01-8. Available from: Sociedad Mexicana de Entomologia,
ATTN. Cuauht6moc Deloya, Apartado Postal 63, 91000 Xalapa, Veracruz, MEXICO
(US$15 + $5 packing and shipping to addresses in the USA).

Hallman et al. (1992) American Entomologist 38: 22-32 give thumbnail accounts of
entomological societies in the Americas south of the USA. To the best of my knowl-
edge, none of these societies has ever produced such a comprehensive account of its
history and current activities as has the Sociedad Mexicana de Entomologia (SME,
the Mexican Entomological Society).
Founded in 1952, SME includes in its 10 principles (Chapter 1) the study of insects
and related arthropod taxa of the Mexican fauna by Mexican nationals and foreigners,
comprising the taxonomy, zoogeography, ecology, and biology of these taxa, and methods
for the control of pest species among them. Chapter 2 is a brief sketch of past-presidents
(each of whom served for two years), honors awarded by SME, the founding in 1962 of
the journal Folia Entomol6gica Mexicana, the production of newsletters, meetings (an
annual congress was inaugurated in 1975), and the existence of regional delegations.
Chapter 3 details the organization of meetings, the composition of the governing
board, and the actions of organizing committees. Chapter 4 explores the production of
Folia Entomol6gica Mexicana and other publications. Chapter 5 examines attendance
at annual congresses, and the sub-disciplines of the participants. Chapter 6 looks at
the direction followed by SME and compares it with other societies in the Americas
south of the USA.
Chapter 7 has a directory of active members in 1995-1996. It explains SME's much
larger total directory which, it is planned, should become searchable by internet early
in 1998. Chapters 8 and 9 deal with the library maintained by SME at the Instituto
Nacional de Diagn6stico y Referencia Epidemiol6gicos (INDRE) in Mexico City, the
agreement establishing the housing of this library, and a detailed list of the journals
that it holds by exchange with other societies nationally and internationally (the list
is impressive) and a few books and theses. Chapter 10 is an analysis of editorial stan-
dards of Folia Entomol6gica Mexicana by its editor. Chapter 11 has three indices of
the contents of that journal. The first is an author index. The second is a subject index
using such headings as "medical and veterinary entomology", "behavior" and "physi-
ology", and "economic entomology" subdivided by agricultural crop. The third is a 39-
page author/title index subdivided taxonomically at the levels of order and family.
The final 6 chapters (12-17) contain the current statutes, the rules for organization
of meetings and activities, the rules for organization of national meetings, the rules
for awarding prizes to students for theses and dissertations, and function of two spe-
cial delegations to SME.
What other entomological society from Florida southward could now recount its
history in such detail? This book is a challenge to the other entomological societies
from Florida to Argentina to do as adequate a job before their historical records are
lost or damaged.
J. H. Frank
Entomology/Nematology Department
University of Florida
P.O. Box 110620
Gainesville, FL 32611-0630




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