• TABLE OF CONTENTS
HIDE
 Front Cover
 Table of Contents
 Introduction
 Review of literature
 Method of procedure
 Results and discussion
 Summary and conclusions
 Literature cited
 Acknowledgement














Group Title: Bulletin - University of Florida. Agricultural Experiment Station ; no. 720
Title: A synecological study of the imported fire ant eradication program
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Permanent Link: http://ufdc.ufl.edu/UF00027232/00001
 Material Information
Title: A synecological study of the imported fire ant eradication program
Series Title: Bulletin University of Florida. Agricultural Experiment Station
Physical Description: 42 p. : charts ; 23 cm.
Language: English
Creator: Rhoades, W. C
Murray, R. W
Publisher: Agricultural Experiment Stations, Institute of Food and Agricultural Sciences, University of Florida
Place of Publication: Gainesville Fla
Publication Date: 1967
 Subjects
Subject: Fire ants -- Control -- Florida   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
bibliography   ( marcgt )
non-fiction   ( marcgt )
 Notes
Bibliography: Bibliography: p. 42.
Statement of Responsibility: W.C. Rhoades and R.W. Murray.
General Note: Cover title.
Funding: Bulletin (University of Florida. Agricultural Experiment Station)
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Volume ID: VID00001
Source Institution: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: aleph - 000929319
oclc - 18367529
notis - AEP0099

Table of Contents
    Front Cover
        Page 1
    Table of Contents
        Page 2
    Introduction
        Page 3
    Review of literature
        Page 3
    Method of procedure
        Page 4
        Page 5
        Page 6
        Page 7
    Results and discussion
        Page 8
        Page 9
        Page 10
        Page 11
        Page 12
        Page 13
        Page 14
        Page 15
        Page 16
        Page 17
        Page 18
        Page 19
        Page 20
        Page 21
        Page 22
        Page 23
        Page 24
        Page 25
        Page 26
        Page 27
        Page 28
        Page 29
        Page 30
        Page 31
        Page 32
        Page 33
        Page 34
        Page 35
        Page 36
        Page 37
        Page 38
        Page 39
    Summary and conclusions
        Page 40
        Page 41
    Literature cited
        Page 42
    Acknowledgement
        Page 42
Full Text

Bulletin 720
September 1967






A SYNECOLOGICAL STUDY OF THE
IMPORTED FIRE ANT ERADICATION PROGRAM


W. C. Rhoades and R. W. Murray






Agricultural Experiment Stations
Institute of Food and Agricultural Sciences
University of Florida, Gainesville
J. R. Beckenbach, Director


MR14 1-
3 1AR J 14S


i i -


s 1







CONTENTS


Introduction .. -- -- --- ---- --

Review of Literature ..-- --

Method of Procedure .. ..-----

Results and Discussion ....--

Arthropod and Annelid Studies ...-

Alcohol Pitfalls .. .-- -

Soil Samples ..............---

Litter Samples -- -- --.

Sweep Nets --- -- --- -

Light Traps ...---...---- --

Mammal and Bird Studies .......

Small Mammal Population Survey -

Large Mammal Population Survey

Song Bird Sampling Study ....--

Summer Quail and Dove Call Counts

Wintering Quail Population Survey

Summary and Conclusions -- -----

Literature Cited -------- ---

Acknowledgments -- ----- --.


Page

3

3

4

8

8

8

13

16
--- -- 3

-- --- - 3







.- 17









31

..31

33

35
-- --- -- 8



















38

39
--------- 13


-.-..... 16

--- --.- 17

...-- ----- 20







-.. 4 31
..- ..- 31






423

423
..- 38

- ------ 3 9

.. .- 40


.--.-.-...... 42







A Synecological Study of the Imported
Fire Ant Eradication Program
W. C. Rhoades and R. W. Murray1

INTRODUCTION

Confusion concerning the use of insecticides in large scale
insect eradication programs of the type being reported in this
paper has arisen because of the fact that some scientists have
reported that the use of certain insecticides would kill practically
all wildlife and endanger the existence of man, while others have
reported that the proper use of these materials is essential to
the livelihood of man, with little harm being done to wildlife.
In May 1959 the Florida Agricultural Experiment Station,
the Florida Game and Fresh Water Fish Commission, and the
Plant Industry Division2 of the Florida Department of Agri-
culture entered into a cooperative agreement to study the effects
of a large scale insect eradication program. The one agreed
upon for this study was the eradication program for the im-
ported fire ant (Solenopsis saevissima richteri, Forel) which was
being conducted in Florida as well as other Southeastern states.
The objectives of this study were to determine the effects of
granular heptachlor, when used in eradication programs of this
type and magnitude, on other forms of wildlife in the treated
areas.
REVIEW OF LITERATURE
Hoffman et al. (6)3 made intensive studies on the effects of
airplane applications of DDT on forest invertebrates in Pennsyl-
vania. They found a great deal of variation in response among
different kinds of animals and considered their work quite pre-
liminary. These investigators thought that additional studies on
the effects of DDT sprays on the inter-relationships of insects
and their natural enemies would be of great interest and value.
The effect on wildlife of DDT dust used for tick control on
a 206-acre plot of Texas prairie was evaluated by Stickel (10).
He found that ground-feeding birds suffered most severely, while
other birds were less affected. Some reptiles were killed, but
1Entomologist, North Florida Experiment Station, University of Florida,
and Research Biologist, Game and Fresh Water Fish Commission of
Florida.
2Formerly State Plant Board of Florida.
Numbers in parentheses refer to literature cited.







A Synecological Study of the Imported
Fire Ant Eradication Program
W. C. Rhoades and R. W. Murray1

INTRODUCTION

Confusion concerning the use of insecticides in large scale
insect eradication programs of the type being reported in this
paper has arisen because of the fact that some scientists have
reported that the use of certain insecticides would kill practically
all wildlife and endanger the existence of man, while others have
reported that the proper use of these materials is essential to
the livelihood of man, with little harm being done to wildlife.
In May 1959 the Florida Agricultural Experiment Station,
the Florida Game and Fresh Water Fish Commission, and the
Plant Industry Division2 of the Florida Department of Agri-
culture entered into a cooperative agreement to study the effects
of a large scale insect eradication program. The one agreed
upon for this study was the eradication program for the im-
ported fire ant (Solenopsis saevissima richteri, Forel) which was
being conducted in Florida as well as other Southeastern states.
The objectives of this study were to determine the effects of
granular heptachlor, when used in eradication programs of this
type and magnitude, on other forms of wildlife in the treated
areas.
REVIEW OF LITERATURE
Hoffman et al. (6)3 made intensive studies on the effects of
airplane applications of DDT on forest invertebrates in Pennsyl-
vania. They found a great deal of variation in response among
different kinds of animals and considered their work quite pre-
liminary. These investigators thought that additional studies on
the effects of DDT sprays on the inter-relationships of insects
and their natural enemies would be of great interest and value.
The effect on wildlife of DDT dust used for tick control on
a 206-acre plot of Texas prairie was evaluated by Stickel (10).
He found that ground-feeding birds suffered most severely, while
other birds were less affected. Some reptiles were killed, but
1Entomologist, North Florida Experiment Station, University of Florida,
and Research Biologist, Game and Fresh Water Fish Commission of
Florida.
2Formerly State Plant Board of Florida.
Numbers in parentheses refer to literature cited.






mammals were affected very little, if at all. Springer and Webster
(9) investigated the effects of DDT applications in New Jersey
tidal salt marshes. They found that birds apparently suffered
little direct harm, though local movements of swallows and gulls
occurred in response to variations in food supply.
An exodus of birds from areas in the Mississippi River bot-
tom, apparently due to depletion of their food supply caused by
DDT treatment, was noted by Couch (3). The findings of
Rogers (7) corroborated those of Couch. The whistling-cock
count of bobwhite quail and the dove cooing-call count were used
by Rosene et al (8) as an indicator for breeding populations of
these birds.
Effects of certain insecticides on earthworms was investi-
gated by Doane (4). He found that they could accumulate large
amounts of DDT without being killed. Baker (1) observed a
reduction in earthworm activity near elm trees that had been
treated the previous year with DDT. After spraying elm trees
with DDT, Barker (2) found that moderate quantities of the
pesticide were concentrated in earthworms.

METHOD OF PROCEDURE
Three ecologically similar areas in northwest Florida were
elected for this study. Each of these areas consisted of approxi-
mately 1,280 acres. These were designated as Area 1, Area 2,
and Area 3. Every effort was made to select areas having sim-
ilar types of habitat and land-use practices. The areas were
selected by representatives of the three cooperating state agen-
cies through the use of aerial photographs and by land survey.
Land use practices varied very little throughout the period
of study. This is shown in Table 1.

Table 1-Land use. 6-year average.
Percent Percent Percent Percent Approximate Acres
Area Cultivated Pasture Fallow Timber Infested with fire ants
1 19.3 19.2 1.5 60.0 512
2 16.0 24.5 3.5 56.0 563
3 24.7 24.5 3.8 47.0 None

Cultivated crops on these study areas consisted primarily of
corn (Zea mays L.), peanut (Arachis hypogaea L.), and upland
cotton (Gossyium hirsutum L.). The pastures were predomi-
nately Pensacola bahiagrass (Paspalum notatum Fluegge) and
coastal bermudagrass (Cynodon dactylon (L.) Pers.). Fallow
fields consisted mostly of native weeds and grasses; cocklebur






(Xanthum spp.) and crabgrass (Digitaria spp.) were the pre-
dominant species. Timber on these areas was composed pre-
dominately of pines, primarily Pinus taeda L., and of oaks
(Quercus spp.).
Two of the selected areas were heavily infested with im-
ported fire ants, while the other was not infested. Area 1, which
was infested, was selected as the one to be treated with 1.25
pounds technical heptachlor, in granular form, per acre. Area 2,
also infested, was not treated but was used to determine the
effect of imported fire ants on other forms of wildlife. Area 3
had no infestation of fire ants and was used as the check area.
Each of the above areas was subdivided into four blocks of
equal size with each block being ecologically similar.
The methods for sampling arthropod and annelid populations
were as follows: 1. alcohol pitfall, 2. soil sample, 3. sweep net,
4. litter sample, and 5. light trap. Methods of censusing mam-
mal and bird populations were as follows: 1. line trapping on a
given number of traplines in each block for small mammals,
2. track counting on dirt roads and fire lanes for large mam-
mals, 3. traversing a given number of routes by foot at regular
intervals and recording birds heard and seen for song bird
sampling, 4. quail "bob-whiting" and dove "cooing" calls for
summer counts, and 5. quail "covey-calls" and dove "cooing"
for winter censusing.
Pre-treatment sampling was begun in September 1959 and
continued at monthly intervals through August 1960 for arthro-
pod and annelid studies. For mammal and bird studies pre-
treatment sampling began in May 1959 and continued at monthly
intervals through August 1960. Population densities, or what
would be considered as normal populations, were established
during this period. Indicator forms were also selected during
this time. A base rating of 100 percent was given to each in-
dicator species, based on the actual number of arthropod and
annelid specimens caught each month (Table 2). Tables 4
through 8 show the populations of mammals and birds on these
areas during the period of this study.
Area 1 was treated by airplane on September 20, 1960, with
1.25 pounds technical heptachlor per acre. Post-treatment sam-
pling began one week later and continued at monthly intervals
through August 1962 and then at bi-monthly intervals from
September 1962 through August 1964.
The use of the words normal and abnormal in this bulletin
refer to fluctuations in arthropod populations caused by climatic
conditions as well as other factors such as diseases and natural









Table 2.-Number of Arthropods and Annelids caught expressed as percentages of number caught during period September 1959
through August 1960 when base level populations were established.

Area 1 Area 2 Area 3
Infested-Treated Infested-Untreated Uninfested-Untreated
Method of Indicator 1959- 1960- 1961- 1962- 1963- 1959- 1960- 1961- 1962- 1963- 1959- 1960- 1961- 1962- 1963-
Collection Species 60* 61** 62** 63** 64** 60* 61** 62** 63** 64** 60* 61"* 62** 63** 64**


Alcohol
Pitfall


Soil Samples
Crop Land

Pine Timber

Fallow Field


Litter Samples
Pine Timber

Fallow Field


Spiders 3780
T. carolina 1182
T. virginica 1241
P. bicincta 1432
G. assimilis 1491
F. auricularia 1069
C. falli 1952
Annelids 391


C. fall
Annelids
C. fall
Annelids
C. falli
Annelids


78 105 142 141
42 99 110 115
45 101 99 106
41 102 120 121
56 109 114 113
63 107 110 118
61 115 120 119
74 104 116 121


44 102 105 110
69 110 103 105
80 110 112 115
78 103 102 109
51 105 114 125
71 106 103 110


A. grandis 161 52 95 106 113
A. bipunctata 176 51 105 107 112
A. grandis 135 86 109 99 103
A. bipunctata 161 56 97 108 106


2692 93 109 98 99
1108 87 118 124 120
1171 92 100 99 105
1349 99 102 125 119
1725 102 101 99 98
1933 110 113 120 124
1124 99 101 122 121
277 103 115 120 122


488 97 102 110 120
167 101 112 109 111
465 105 118 107 122
159 112 122 99 107
679 96 103 108 116
155 97 116 105 98


151 104 110 115 108
154 111 120 110 113
134 112 118 121 109
150 104 122 116 123


3218 96 108 102 105
1123 91 111 112 118
1268 99 113 114 119
1377 99 98 116 128
1582 101 120 110 112
1072 103 106 109 108
1872 99 110 129 126
261 110 110 120 118


574 104 107 117 109
162 111 118 106 114
472 107 119 120 115
161 103 105 99 104
575 105 112 121 114
160 103 115 104 101


166 108 102 130 110
159 98 105 111 107
139 106 117 102 121
154 98 115 120 106








Table 2.-Number of Arthropods and Annelids caught expressed as percentages of number caught during period September 1959
through August 1960 when base level populations were established. (Continued)

Area 1 Area 2 Area 3
Infested-Treated Infested-Treated Infested-Treated
Method of Indicator 1959- 1960- 1961- 1962- 1963- 1959- 1960- 1961- 1962- 1963- 1959- 1960- 1961- 1962- 1963-
Collection Species 60* 61** 62** 63** 64** 60* 61** 62** 63** 64** 60* 61** 62** 63** 64**


Locustidae 1317 60 112 109 116
C. flaviceps 1682 75 107 103 110
Locustidae 1212 62 110 111 107
C. flaviceps 8160 67 98 105 112

C. fall 16940 35 105 111 107
C. calidum 1469 30 95 103 114
E. vittata 2484 40 90 118 99
Phyllophaga
spp. 4285 49 108 126 109
D. 12-punctata 1780 38 85 103 113
T. carolina 1287 25 86 96 105
L. americanus 2290 78 101 103 106
N. viridula 2458 67 103 93 107
C. flaviceps 27466 81 100 99 116
P. bicincta 2507 44 97 111 117
P. quinquema-
culata 271 61 92 113 100
H. zea 2417 53 88 112 114
A. virgo 1177 90 95 114 110
E. acrea 1312 94 110 104 109


1150 100 105 102 107 1127 104 117 106 109
1687 110 106 110 103 1807 112 118 112 106
1247 106 98 108 112 1334 110 129 108 117
1464 96 106 118 114 6727 122 127 116 104

16486 100 107 112 107 16071 110 114 124 109
1346 103 112 132 106 1380 103 105 113 112
2449 105 108 134 115 2569 89 97 139 124

4339 125 122 126 112 4629 120 132 111 105
1696 102 110 135 126 1707 103 105 128 117
1302 102 104 100 120 1256 98 109 130 125
2333 103 103 115 107 2308 106 100 104 112
2534 99 93 95 103 2590 97 101 94 105
28062 115 110 114 112 29235 113 107 101 109
2657 103 100 97 113 2820 95 96 105 108

244 109 117 114 120 259 109 106 119 108
2496 102 107 107 113 2388 104 102 118 108
1199 100 103 119 119 1277 97 107 105 107
1359 89 90 101 112 1426 100 95 104 110


*Pre-Treatment-Total number specimens captured.
**Post-Treatment-Percent of number captured during pre-treatment sampling period.


Sweep Nets
Pasture Land

Fallow Field


Light Traps







enemies which have an influence on the numbers of these ani-
mals. For instance, in a given area, there may be a serious out-
break of a certain species, which in turn spurs the build-up of
natural enemies or diseases, or both, peculiar to this species.
This would reduce the number of the original species. Likewise
the number of specimens of the natural enemy would decline due
to the lack of available food furnished by the original species.
Climatic conditions will also affect the population of certain
species of arthropods.

RESULTS AND DISCUSSION
Arthropod and Annelid Studies
Work on this phase of the project was begun in May 1959
by conducting a survey of the selected areas to determine land
use practices so as to locate all methods of sampling in ecolog-
ically similar habitats. This survey was accomplished with the
assistance of county extension agents and by consulting with
land owners and farmers in these study areas.

Alcohol Pitfalls
The pitfalls used were similar to those described by Fichter
(5) but were modified so as to be 1 meter in diameter at the
soil surface (Figure 1). Four pitfalls were installed in each
study area, one in each block.
Indicator species selected for study under this method of
collecting were as follows:
1. Araneida (all species of spiders)
2. Tetracha carolina L. Tiger beetle.
3. Tetracha virginica L. Tiger beetle.
4. Prosapia bicincta (Say). Two-lined spittlebug.
5. Gryllus assimilis (Fab.) Common field cricket.
6. Forficula auricularia L. European earwig.
7. Conoderus falli Lane. Southern potato wireworm.
8. Annelida. All species of earthworms.
1. Araneida. All species of spiders were grouped together
for this study; however, approximately 79% of those captured
belonged to the family Lycosidae and 13% to the family Gna-
phosidae, with the remaining 8% distributed among 11 other
families.
The population of spiders was reduced rapidly following
treatment of area and remained at a low level for four months;
however, it began increasing rather rapidly and had reached


























Figure 1. Alcohol pitfall.


base level within eight months. Numbers of spiders captured
on the other two study areas remained fairly constant through-
out the entire study period, indicating that the fire ants had no
effect upon their numbers. Some fluctuations in numbers cap-
tured was noted from month to month, but this was probably
caused by climatic conditions and variations in numbers of
natural enemies, since this took place on all areas at approxi-
mately the same degree (Figure 2).
2. Tetracha carolina and T. .-';, ,i,,;,i. The insecticide re-
duced both species of tiger beetles to zero within two months
after it was applied. They remained at a low level for several
months, after which their numbers began increasing until they
had reached base level during the fifteenth month following
insecticide application. No beetles were caught in any of the
areas during December, January, February, or March in any
test year. The populations remained fairly stable on the other
two areas throughout the period. The variations shown for
Areas 2 and 3 in the accompanying graphs were considered to
be normal (Figures 3 and 4).
3. Prosapia bicincta. The treatment reduced the number of
spittle bugs to zero within three months after it was applied.
The population fluctuated for a few months and then began to
increase steadily, beginning with the ninth month and con-
tinuing until it reached the base level within 13 months after


-'q W

KC fS iI









/~\a


AREA I FIRE ANTS-TREATED
AREA 2 ==-: FIRE ANTS-UNTREATED
AREA 3-- NO FIRE ANTS- UNTREATED


MONTHS SINCE TREATMENT

Figure 2. Spiders. Alcohol pitfall sampling.



treatment and varied very little thereafter. There was some
variations in population on the other two areas, but this was
considered to be normal. No spittle bugs were caught in De-
cember, January, or February in any of the test years (Figure
5).
4. Gryllus assimilis. Field cricket population was reduced
to 42% of base level within one week after application and to
zero within five months. The numbers collected began increas-
ing six months following treatment and increased steadily until
they reached normal within one year; then they continued at
base level with little variation for the remainder of the period.
The populations varied some in the other areas but were not
considered to be abnormal, because in most cases the variation
was above the base level set by collections during the pre-treat-
ment sampling period (Figure 6).
5. Fortificula auricularia. The earwig population was dras-
tically reduced within one week following treatment and re-
mained at a low level for four months, after which earwigs
began to slowly increase in numbers until they reached normal
base level within two months. The population variation that
followed during the remainder of the period was considered to













A \


7-
NC/A~


A /


AREA I FIRE ANTS-TREATED
AREA 2- FIRE ANTS--UNTREATED
AREA 3--" NO FIRE ANTS- UNTREATED


S 5 0 F5 20 25 30 35 40 45 50
MONTHS SINCE TREATMENT

Figure 3. Tetracha carolina. Alcohol pitfall sampling.


J--


0
3















AREA I FIRE ANT- TREATED
AREA 2= FIRE ANTS UNTREATED
AREAS'--- NO FIRE ANTS- UNTREATED



o 5 0 15 20 25 30 35 40 45 50
MONTHS SINCE TREATMENT-


Figure 4. Tetracha virginica. Alcohol pitfall sampling.








140-


1201

110D




60
580

40-






30 AREA I FIRE ANTS TREATED
AREA 2 -- FIRE ANTS-UNTREATED
20 AREA -.NO FIRE ANTS-- UNTREATED

10D


0 5 10 15 20 25 30 35 40 45 50
MONTHS SINCE TREATMENT


Figure 5. Prosapia bicincta. Alcohol pitfall sampling.





140-
S /,\ A

/ \I .A
,\ '\ \/




90\

S80 'I
E V

L 70-

60-

50-

40-
30- AREA \--- FIRE ANTS-TREATED
AREA2--= IRE ANTS- UNTREATED
20- AREAS --- NO FIRE ANTS- UNTREATED

10-

0-
0 5 10 15 20 25 30 35 40 45 50
MONTHS SINCE TREATMENT

Figure 6. Gryllus assimilis. Alcohol pitfall sampling.






be normal. Collections on Areas 2 and 3 were also considered to
be normal, though some variation was noted (Figure 7).
6. Conoderns falli. The wireworm population was reduced
to 80% of base level within one week following application of
insecticide and to zero within five weeks. The numbers collected
began increasing the sixth month following treatment and con-
tinued at a slow rate until they reached base level during the
thirteenth month. The population varied somewhat during the
remainder of the period, but when this was compared with the
other areas, it was not considered abnormal (Figure 8).
7. Annclids. Earthworms were affected by the treatment,
but to a much lesser degree than were the arthropods. They were
only reduced to 507% of base level at the end of four months
following treatment. The population then varied somewhat be-
low the base level for the next several months before leveling
off at or above base level. Populations on the other study areas
remained at or above the base set during pre-treatment sampling
for the entire period of study (Figure 9).

Soil Samples
Three soil samples, each consisting of 1 cubic foot of soil,
were taken once each month from crop land, open pine timber
land, and fallow field located in each block of each area. Each
sample was sifted through an 8-mesh soil sieve in the field. The
specimens were preserved in 70% alcohol and brought into the
laboratory for identification. Wireworms (Conoderus falli) and
earthworms annelidss) were selected for this phase of the study.
1. Conoderus falli. Wireworm population was severely re-
duced by the treatment and remained below base level for a
period of 11 months. It varied some for the next eight months
and then leveled off near normal for the remainder of the test
period. The population varied on the other two study areas, but
in most cases this was above the base level (Figure 10).
2. Annelids. The reduction in earthworm population was
not as severe as it was for wireworms, reaching a low 57% of
base level after two months. Earthworms began increasing after
three months, reached base level within 14 months, and re-
mained there with little variation for the remainder of the test
period. The populations on the other study areas varied some-
what throughout the period, but in every case this was above
the base level (Figure 11).











'N.,

/ V


AREA I FIRE ANTS-TREATED
AREA 2 FIRE ANTS- UNTREATED
AREA 3 NO FIRE ANTS-UNTREATED


5 10 15 20 25 30 35 40
MONTHS SINCE TREATMENT

Figure 7. Forficula auricularia. Alcohol pitfall sampling.


'S


,2


AREA I -- FIRE ANTS- TREATED
AREA 2 : FIRE ANTS- UNTREATED
AREA 3. -- -NO FIRE ANTS UNTREATED


10 15 20 25 30 35
MONTHS SINCE TREATMENT


40 45


Figure 8. Conoderus falli. Alcohol pitfall sampling.





























AREA I FIRE ANTS-TREATED
AREA2-;- FJRE ANTS UNTREATED
AREA --- NO FIRE ANTS-UNTREATED


0 15 20 25 30 35 40 45 50
MONTHS SINCE TREATMENT

Figure 9. Earthworms. Alcohol pitfall sampling.


12-0 -
A / ./ /. ,. /*
*/ ^-^ ^*^^


AREA I -- FIRE ANTS- TREATED
AREA23 FIRE ANTS--UNTREATED
AREA -- NO FIRE ANTS UNTREATED


S 5 10 15 20 25 30
MONTHS SINCE TREATMENT


Figure 10. Conoderus fall. Soil sample.


S I I I
I I I I
35 40 45 50


ri





















AREA I -- FIRE ANTS-TREATED
AREA 2 =-= FIRE ANTS- UNTREATED
AREA 3.-- NO FIRE ANTS- UNTREATED


MONTHS SINCE TREATMENT

Figure 11. Earthworms. Soil sample.

Litter Samples
Litter samples were taken once each month from open pine-
timber and from fallow fields in each block. These samples were
collected from an area 18 inches by 36 inches at six different
spots in each location. The litter was placed in waterproof paper
bags, which were sealed and brought into the laboratory, where
litter was processed through modified Berlese Funnels (Figure
12). The arthropod specimens were preserved in 70% alcohol
until they could be separated and identified. The two indicator
species selected for this phase were Anthonomis grandis Bohe-
man (boll weevil) and Adalia bipunctata (Linnaeus) (two-
spotted lady beetle).
1. Anthonomis grandis. The overwintering population of
this insect was reduced during the first winter following appli-
cation of insecticide. During the succeeding years of this study,
the population was at base level or above with little fluctuation.
Population on the other areas remained at base level or above
throughout the period (Figure 13).
2. Adalia bipunctata. The treatment reduced the overwin-
tering population of lady beetles the first winter following appli-
cation. They reached normal numbers during the second winter
and stayed there, with little variation, for the remainder of the


P `~








p



















Figure 12. Modified Berlese funnel.

period. The population varied somewhat in the other areas, but
this was considered normal (Figure 14).
Sweep Nets
Samples were taken once each month from pasture land and
fallow-fields in each block. Twenty-five sweeps were made at
three locations in each of the areas and combined to make a
total of 75 sweeps for each sample. These specimens were sealed
in waterproof bags and brought into the laboratory where they
were processed and identified. The forms selected as indicators
for this phase of the study were all species collected belonging
to the grasshopper family (Acrididae) and a leafhopper, (Car-
neocephala flaviceps).
1. Acrididae. The treatment drastically reduced the grass-
hopper population immediately following application of the in-
secticide. The population began increasing rather rapidly the
summer following treatment but did not reach base level until
the second spring and summer, which was 20 months following
the treatment. In conjunction with this method of study on
grasshoppers, soil samples were taken in fence rows and road-
sides for sampling egg deposition. The number of egg pods
found was far less in and around the treated area the first
winter immediately after treatment than it was during the pre-













d .o ^ ^ "
in o] .... ... / '/%


AREA I FIRE ANTS--TREATED
AREA 2 FIRE ANTS- UNTREATED
AREA 3 NO FIRE ANTS- UNTREATED


CIJ


5 10 15 20 25 30
MONTHS SINCE TREATMENT


35 40 45 50


Figure 13. Anthonomis grandis. Litter sample.


AREA I FIRE ANTS- TREATED
AREA 2 === FIRE ANTS- UNTREATED
AREA 3 .-- NO FIRE ANTS UNTREATED


jI 15 20 25 30 35 4(
MONTHS SINCE TREATMENT

Figure 14. Adalia bipunctata. Litter sample.


9


C~o

qi~ta
















4 .\ J\


I-~
,~T r


AREA I ---- FIRE ANTS -TREATED
AREA 2a= FIRE ANTS--UNTREATED
AREA 3 -- NO FIRE ANTS UNTREATED


I I I . . . I' '
5 10 15 20 25 30
MONTHS SINCE TREATMENT


35 40 45 50


Figure 15. Locustidae. Sweepnet sample.


140-

130-

120-
ORE- 2 FIRE NTS UN



90

Z80-



60-

50- AREA I c- FIRE ANTS--TREATED

40- AREA 3 -- NO FIRE ANTS-- UNTREATED

30-

20-

10`


0 5 10 15 20 25 30 35 40 45 50
MONTHS SINCE TREATMENT

Figure 16. Carneocephala flaviceps. Sweepnet sample.


9100
90-IS






ceding winter or the second winter. The number of specimens
caught and the number of egg pods recovered on the other study
areas were fairly constant throughout the study (Figure 15).
2. Carneocephala flaviceps. The leafhoppers were affected
very little by the treatment, as is shown in Figure 16.

Light Traps
The light traps used in this study were the 15-watt black
light fluorescent omnidirectional survey traps (Figure 17).
These traps were developed and constructed by the Agricultural
Research Service, U. S. Department of Agriculture, and loaned
to the Experiment Station for use in this study. Four of these
light traps were placed in each of three study areas, one trap
in each block. They were placed on improved pasture land ad-
jacent to cultivated crop land and as close to pine timber as
possible. Care was taken to place them in similar ecological
situations on all areas. This was done to attract similar species
of insects. The traps were operated on the twentieth day of
each month throughout the study except when impossible be-
cause of weather conditions. All specimens were caught in 70%
alcohol in the metal cans placed below the black light bulbs. The
specimens were identified to family level. Indicator species
selected for this phase were as follows:
1. Conoderus falli Lane. Southern potato wireworm
2. Calosoma calidum (Fabricius). Firey hunter
3. Epicauta vittata (Fabricius). Striped blister beetle
4. Phyllophaga spp. May beetles
5. Diabrotica undecimpunctata howardi. Barber. Spotted
cucumber beetle
6. Tetracha carolina Linnaeus. Tiger beetle
7. Lethocerus americanus (Leidy). Giant water bug
8. Nezara viridula (Linnaeus). Southern green stink bug
9. Carneocephala flaviceps (Riley). Yellow-headed leaf-
hopper
10. Prosapia bicincta (Say). Two-lined spittle bug
11. Protaparce quinquemaculata (Haworth). Tomato horn-
worm
12. Heliothis zea (Boddie). Corn earworm.
13. Apantesis virgo (Linnaeus). Tiger moth
14. Estigmene acrea (Drury). Salt-marsh caterpillar
1. Conoderus falli. The treatment reduced the population
of adult wireworms to zero within three months. They remained
at a low level for 12 months and increased rapidly until they


























Figure 17. Light Trap.


reached base level within 14 months. Their population remained
at or above base level throughout the period. Population varied
somewhat on the other areas, but in most cases this variation
was above the base level established by the pre-treatment sam-
pling period (Figure 18).
2. Calosoma calidum. This species of ground beetle was se-
verely reduced in numbers by the treatment. The population re-
mained at a low level for 12 months and then increased rather
rapidly. The numbers caught reached base level during the
twenty-first month and remained there or above for the re-
mainder of the period. Populations on the other area fluctuated,
but in most instances these fluctuations were above the base level
(Figure 19).
3. Epicauta vittata. The population of the striped blister
beetle was reduced to zero within two months following treat-
ment. They began to increase slowly during the eighth month
and reached 98% of base level during the thirteenth month. The
numbers caught then varied below the base level for the next 10
months before they reached and surpassed normal collections.
With but one exception, the population remained at or above
normal for the remainder of the period (Figure 20). Popula-
tions on the other study areas sustained their pre-treatment
counts with some fluctuation in number of specimens caught.










/ /*


AREA I FIRE ANTS- TREATED
AREA 2:=' FIRE ANTS- UNTREATED
AREA 3 -- NO FIRE ANTS UNTREATED


0 5 10 15 .0 25 30 35 40 45 50
MONTHS SINCE TREATMENT

Figure 18. Conoderus falli. Light trap sample.


Tk.7


AREA FIRE ANTS-- TREATED
AREA 2f=-=, FIRE ANTS-- UNTREATED
AREA 3'-- NO FIRE ANTS- UNTREATED


15 20 25 30
MONTHS SINCE TREATMENT


Figure 19. Calosoma calidum. Light trap sample.


i""'


"""


11-N








lINU-



S120- >




90- /

80-

70-

60-

50-

40-

30 AREA I FIRE ANTS TREATED
AREA 2 FIRE ANTS UNTREATED
20- AREA 3 NO FIRE ANTS- UNTREATED



0 I I, II,,III I I li i II 2i,5, TII
0 5 10 15 20 25 30 35 40 45 50
MONTHS SINCE TREATMENT


Figure 20. Epicauta vittata. Light trap sample.


1k


AREA I FIRE ANTS-- TREATED
AREA 2 -- FIRE ANTS UNTREATED
AREA 3 -- NO FIRE ANTS UNTREATED


5 20 25 30
MONTHS SINCE TREATMENT


Figure 21. Phyllophaga spp. Light trap sample.






4. Phyllophaga spp. May beetle population was severely re-
duced by the insecticide treatment and remained at a low level
for approximately 12 months. It reached base level by the fif-
teenth month and remained there or above throughout the period
of study. Some variation in population was noted on the other
two areas (Figure 21).
5. Diabrotica undecimpunctata howardi. Treatment reduced
the population of striped cucumber beetles to 12% of base level
within two months. It required approximately 13 months to
reach base level, where it remained with little fluctuation for the
remainder of the period. Areas 2 and 3 showed no drastic de-
crease in population at any time (Figure 22).
6. Tetracha carolina. The reduction of this species as meas-
ured by light traps was similar to the reduction as measured
by alcohol pitfalls. The population was reduced to zero two
months after treatment. The only difference was that the popula-
tions began increasing eight months following treatment and
reached base level during the fourteenth month. Populations re-
mained rather steady on the other areas (Figure 23).
7. Lethocerus americanus. Giant waterbug population was
reduced to 20% of normal within two months after treatment.
However, when collections began the spring following treatment
(none were caught during the months of November, December,
January, or February in any test year) the population was at
approximately base level, where it remained, with little varia-
tion, for the rest of the period. The population of this species
was not disturbed on the other areas (Figure 24).
8. Nezara viridula. The population of the southern green
stink bug was reduced to 39 % of normal within one month after
treatment. It reached base level the third month where it re-
mained, with little variation, throughout the period. Some varia-
tion took place on the other two areas, but this was considered
to be normal (Figure 25).
9. Carneocephala flaviceps. There was very little difference
in percentages of base level established during pre-treatment
sampling between leafhoppers caught with the sweep net (Fig-
ure 14) and the light trap (Figure 26). The leafhoppers were
affected very little by the treatment. In most instances, popula-
tions on the other areas remained at or above base level during
the entire period.
10. Prosapia bicincta. Treatment reduced the population of
spittle bugs to zero within two months. The number of speci-
mens caught began increasing within eights months and con-
tinued to increase, with exception of one month, until they






























AREA I FIRE ANTS-- TREATED
AREA 2 = FIRE ANTS-- UNTREATED
AREAS NO FIRE ANTS UNTREATED


5 10 15 20 25 30 35 40 45
MONTHS SINCE TREATMENT


Figure 22. Diabrotica undecimpunctata. Light trap sample.


AREA I- FIRE ANTS--TREATED
AREA 2 == FIRE ANTS-UNTREATED
AREA --- NO FIRE ANTS- UNTREATED


MONTHS SINCE TREATMENT


Figure 23. Tetracha carolina. Light trap sample.












.4
," ^ ,v
,/ / -"^


AREA I FIRE ANTS -- TREATED
AREA 2 FIRE ANTS-- UNTREATED
AREA 3 --- NO FIRE ANTS-- UNTREATED


ID IS 2D 25 3D 35 4D
I..-.,


0 15 20 25 30 35 40
MONTHS SINCE TREATMENT


Figure 24. Lethocerus americanus. Light trap sample.


45 50


.\/ `C


AREA I FIRE ANTS-- TREATED
AREA 2 a--- FIRE ANTS- UNTREATED
AREA 3 -- D NO FIRE ANTS UNTREATED


MONTHS SINCE TREATMENT

Figure 25. Nezara viridula. Light trap sample.


IIJ


A


/ i\ -- f-"


4


9 1
Y











/\


/


- _L4


AREA I -- FIRE ANTS TREATED
AREA 2 -FIRE ANTS UNTREATED
AREA 3 -- NO FIRE ANTS UNTREATED


I . I . I . I I I
5 10 15 20 25 30
MONTHS SINCE TREATMENT


35 40 45


Figure 26. Carneocephala flaviceps. Light trap sample.


AREA I FIRE ANTS TREATED
AREA 2 a== FIRE ANTS UNTREATED
AREA 3 -- NO FIRE ANTS UNTREATED


/




C.


..


MONTHS SINCE TREATMENT

Figure 27. Prosapia bicincta. Light trap sample.


- I


I / V6


i .V






reached base level within 13 months (Figure 5). Numbers col-
lected with the alcohol pitfall method (Figure 5) were similar
to those collected with light traps. The population on the other
areas remained stable throughout the period (Figure 27).
11. Protoparce quinquemaculata. Numbers of tomato horn-
worm moths were reduced to zero within two months after treat-
ment. It took 11 months for this species to reach base level
population (Figure 28). Population remained undisturbed on
the other areas.
12. Heliothis zea. The corn earworm adult population was
severely reduced immediately following treatment and remained
below base level throughout the next year. It did not reach
normal until 20 months following treatment. The population re-
mained, with few exceptions, at or above base level on the other
areas (Figure 29).
13. Apantesis viro. Tiger moth population was reduced by
the treatment immediately after application but increased rapid-
ly, beginning in March, seven months following treatment. It
had reached base level by May or within nine months. Popula-
tion on the other areas remained fairly stable throughout the
period (Figure 30).
14. Estigmene area. Heptachlor treatment reduced the salt
marsh caterpillar population to 10% of base level within two
months. It began increasing and within eight months reached
base level, where it remained with little fluctuation throughout
the remainder of the study period. The slight variations of popu-
lations in other areas were considered normal (Figure 31).
Two 10-acre plots, one in each of Areas 1 and 2, were selected
for more detailed study of the fire ants, their ability to increase
and spread, and the length of time it took to re-establish them-
selves in the treated area.
The plot in Area 1 had 117 active colonies when the study
began in September 1959. This number had increased to 187
colonies when it was treated with 1.25 pounds technical hep-
tachlor per acre in September 1960. The first ants were eradicat-
ed from this plot within one month following treatment, and it
remained void of active colonies for a period of 22 months. One
colony had established itself on the treated area during the
twenty-third month following treatment. Active colonies began
increasing in number until at the end of 48 months there were
193 colonies on this plot.
The plot in Area 2 which received no treatment had 96 active
colonies when the study began. The colonies gradually increased










77


AREA I- FIRE ANTS TREATED
AREA 2 FiRE ANT UNTREATED
AREA 3 -- NO FIRE ANTS UNTREATED


0 5 10 15 20 25 30
MONTHS SINCE TREATMENT


35 40 45 50


Figure 28. Protoparce quinquemaculata. Light trap sample.


i\


AREA I-- FIRE ANTS TREATED
AREA 2 FIRE ANTS UNTREATED
AREA NO FIRE ANTS UNTREATED


~5nj*~J


ncI. I- ~


0 5 10 15 20 25 30 35 40 45 50
MONTHS SINCE TREATMENT

Figure 29. Heliothis zea. Light trap sample.


ion I


A !I









140-

130-

120-



100

90-

I80-
HLJ
70 -
w
-60-

50-

40-

30- AREA I -FIRE ANTS TREATED
AREA 2 F-FIRE ANTS UNTREATED
20- ANTS 3 NO FIRE ANTS UNTREATED

10-

0
0 5 10 15 20 25 30 35 40 45 50
MONTHS SINCE TREATMENT

Figure 30. Apantesis virgo. Light trap sample.


AREA I FIRE ANTS TREATED
AREA 2 -- FIRE ANTS UNTREATED
AREA 3 -- -NO FIRE ANTS UNTREATED


10 15 20 25 30 35 40
MONTHS SINCE TREATMENT


Figure 31. Estigmene acrea. Light trap sample.






in number until at the end of the study there were 220 active
colonies (Table 3).

Mammal and Bird Studies
Five methods of sampling the bird and mammal populations
were employed in this phase of the study. These were as fol-
lows: 1. a summer small mammal sampling survey accomplished
by live trapping on a given number of traplines in similar
habitats on each area; 2. a large mammal sampling survey ac-
complished by track counting on dirt roads or fire lanes at regu-
lar intervals; 3. a song bird sampling study accomplished by
traversing a given number of routes on each area by foot at
regular intervals and recording birds heard and seen; 4. a
summer quail and dove call count accomplished by traveling a
given number of roads periodically, stopping at regular intervals,
and recording the number of quail "bob-whiting" and number
of doves "cooing"; and 5. a census of the wintering quail popu-
lation accomplished by listening at stations for the covey call
which is given by each covey as it leaves the roosting sites each
morning.

Small Mammal Population Survey
The plan employed in this survey consisted of live trapping
established traplines with Sherman live traps. Traplines were
selected in habitats which were reasonably similar on all three
areas. All lines were established on a similar pattern, using 50
traps, two at each of 25 stations set 50 feet apart. The only
exception to this pattern was in the stream habitat, where only
25 traps were used. All lines were numerically designated ac-
cording to habitat and number of line. The numerical designa-
tions of the habitat types selected on each area were as follows:
1. Fallow field (two traplines on each area).
2. Stream (one line on each area).
3. Sparse oak-pine woodland (one line on each area).
4. Cornfield bordering woodland (one line on each area).
5. Fencerow between pasture and road (one line on each
area).
6. Fencerow between cornfield and road (one line on each
area).
The same traplines were used throughout the study. The pat-
tern for all trapping on each line was based on a set of three
consecutive trapping nights. There were, therefore, 150 trap-
nights per line on each area (57 trap-nights on habitat, two on
each area) during each year of study.

















Table 3.-Number of active fire ant colonies on a 10-acre plot in each of Areas 1 and 2.

Area Sept. Oct. Nov. Dec. Jan. Feb. Mar. Apr. May June July Aug.
1 1959-60* 117 117 117 117 117 117 119 146 188 187 187 187
1960-61** 187 0 0 0 0 0 0 0 0 0 0 0
1961-62** 0 0 0 0 0 0 0 0 0 0 0 1
1962-63** 3 4 4 4 4 4 6 10 16 19 31 36
^ 1963-64** 81 83 83 83 83 83 93 160 117 188 190 193

2 1959-60 96 96 96 96 96 97 97 109 148 148 148 148
1960-61 159 159 159 159 195 159 159 163 184 198 198 198
1961-62 209 209 209 209 209 209 199 199 195 195 195 195
1962-63 201 201 201 201 201 201 205 210 230 230 228 228
1963-64 228 228 228 228 228 218 207 212 212 216 220 220
Pre-treatment counts
"Post-treatment counts






Bait used for trapping was rolled oats. All animals captured
were examined and released. Examination consisted of identifi-
cation, weight, sex and age determination, reproductive condi-
tion, molt, and marking. Marking was by the toe clip method.
Trapping was not conducted during 1962 because conclusive
results were obtained during the first post-treatment trapping
period. Because of the short life span of these animals, it was
felt that any effects of the insecticide would have been noted
during the first year following treatment.
The most common species captured on the three areas were
cotton rat (Signmodon hispidus), cotton mouse (Peromyscus
gossypinus), old-field mouse (Peromyscus polionotus), and house
mouse (Mus musculus). Species of minor abundance captured
were golden mouse (Peromyscus nutalli) and rice rat (Oryzo-
mys palustris).
A trapping index for each area was formed for the purpose
of showing population changes that might occur. This figure
is the number of individual animals captured for each 100 ap-
plicable trap-nights. It could be calculated for each species per
area, or for all species by the following equation:
X 100.
No. individuals 150
Table 4 shows the average index per acre for both the pre-
treatment and post-treatment trapping periods.
Although the trapping index dropped on Area 1 following
treatment, it was not believed to be of any appreciable value,
since there was a drop in all three areas. The most pronounced
drop occurred on Area 3. Rodent populations are generally
eruptive or cyclic in Florida. It is believed that such population
phenomena were responsible for the population drop on Area
1 rather than effects of the insecticide.

Large Mammal Population Survey
The method of conducting this survey consisted of counting
tracks of the larger mammals at monthly intervals on dirt roads
or fire lanes. Counting was done on roads where they traversed
the interior of the area. This method was employed on Areas
1 and 2. These roads were graded frequently by the County
Road Department, thereby making tracking conditions satis-
factory. Tracking was done on fire lanes on Area 3, since there
were no interior roads in the area. Fire lanes were plowed regu-
larly by the Florida Forest Service to facilitate tracking condi-
tions. Four miles of roads or fire lanes were traversed on each







Table 4.-Small mammal data for each trapline.

Pre-treatment (two years)
Total Total
Captures Individuals Index
Area Habitat Line (all species) (all species) (all species) Nights
1 1 1 10 7 2.33 300
1 1 2 4 4 1.33 300
1 2 1 15 12 8.00 150
1 3 1 31 18 6.00 300
1 4 1 3 2 0.67 300
1 5 1 16 14 4.67 300
1 6 1 8 6 2.00 300
Total 87 66 3.33 1950

Post-treatment (one year)
1 1 1 9 8 5.35 150
1 1 2 1 1 .68 150
1 2 1 3 3 4.00 75
1 3 1 5 5 3.34 150
1 4 1 0 0 0 150
1 5 1 5 3 2.00 150
1 6 1 0 0 0 150
Total 23 20 2.05 975

Pre-treatment (two years)
2 1 1 3 3 1.20 250
2 1 2 7 5 2.00 250
2 2 1 12 9 7.20 125
2 3 1 4 2 .80 250
2 4 1 12 9 3.00 300
2 5 1 6 5 1.67 300
2 6 1 16 13 4.33 300
Total 60 46 2.03 1775

Post-treatment (one year)
2 1 1 0 0 0 150
2 1 2 1 1 .68 150
2 2 1 0 0 0 75
2 3 1 0 0 0 150
2 4 1 0 0 0 150
2 5 1 5 3 2.00 150
2 6 1 7 7 4.68 150
Total 13 11 1.13 975

Pre-treatment (two years)
3 1 1 21 16 6.40 250
3 1 2 11 6 2.40 250
3 2 1 6 5 6.67 75
3 3 1 4 4 1.60 250


5 1 21 16


9.60 250
5.33 300
5.66 300
5.25 1675


3
3
3
Tntnl


Total







Table 4.-Small mammal data for each trapline. (Continued)
Post-treatment (one year)
Total Total
Captures Individuals Index
Area Habitat Line (all species) (all species) (all species) Nights
3 1 1 1 1 .68 150
3 1 2 0 0 0 150
3 2 1 0 0 0 0
3 3 1 1 1 .68 150
3 4 1 13 11 7.35 150
3 5 1 7 6 4.00 150
3 6 1 6 5 3.34 150
Total 28 24 2.67 900

area, and the tracks of individual animals were recorded. Track-
ing was done within one or two days following heavy rainfall
whenever possible. Imprints are more distinct when made on
wet soil. However, counts could not always be made under these
conditions, since there was only light rainfall during some months
and the soil was either dusty or dry and firm. Under these
conditions some of the smaller tracks, i.e. rabbit and squirrel,
were difficult to distinguish. Undoubtedly many of them were
missed. However, since similar conditions were present on all
the areas, there should have been no bias in results.
This survey began in August 1959. Thirteen counts were
made on each area prior to treatment and 13 following treat-
ments. Results of the counts for each area before and after
treatment are shown in Table 5. The figures are based on tracks
per mile of road or fire lane.
The population of larger mammals remained at approximately
the same level throughout the study on all three areas. There
was no apparent effect of the treatment on the populations on
Area 1. Areas 1 and 2 showed slight increases in most species,
while Area 3 showed a slight decrease. This area also showed
the greatest drop in small mammal populations.

Song Bird Sampling Study
The plan employed in this survey consisted of traversing
established routes on each area by foot and recording the num-
bers and species of birds heard and seen. From four to six
routes were established on each area at the beginning of the
study. These routes were covered at two-week intervals between
March 1959 and March 1962. Thirty-four trips were made to


















Table 5.-Large mammal track counts.
Pre-treatment
Area Rabbit Raccoon Squirrel Skunk Fox Opossum Bobcat Deer Mink
1 2.00 1.60 .60 .30 .20 .20 .20 .00 .00
2 3.20 2.80 1.10 .70 .80 .30 .00 .20 .00
3 3.50 3.10 1.20 .50 2.80 .80 .00 .00 .01
Post-treatment
1 2.70 2.00 .40 .38 .30 .23 .20 .02 .00
2 3.60 2.70 .47 1.20 .90 .23 .00 .20 .00
3 3.30 2.80 .68 .40 2.10 .40 .00 .00 .02







each area prior to treatment and 33 following treatment (Table
6).
There was an increase in the number of individuals on all
areas from the pre-treatment period through the post-treatment
period. This is due to the fact that the pre-treatment period
embraced two summers and one fall-winter period, whereas
the post-treatment period embraced one summer and two fall-
winter periods. Counts were higher during fall-winter periods
when migrant flocks and winter residents were present on the
areas. The increases on Areas 2 and 3 were greater than on
Area 1 because of the large flights of red-winged blackbirds
migrating through these areas during the winter. These flights
did not occur through Area 1.
Species population data of some of the most common perma-
nent residents of the areas showed that some species decreased
more on Area 1 than on Areas 2 and 3 following treatment. The
house wren decreased 26% on Area 1, while it increased 59%
and 53%7, respectively, on Areas 2 and 3. The Bewick's wren
decreased 100 percent on Area 1, while it registered 120% and
56% increase on Areas 2 and 3, respectively. The Maryland
yellowthroat decreased 88% on Area 1 and showed 10% and
5% increase on the other areas. The loggerhead shrike decreas-
ed by 46%7 on Area 1, while it decreased by only 14%o and
22%o respectively on Areas 2 and 3.
These decreases are of little importance because of the small
number of individuals of each species involved. There were also
decreases in individuals of some species on the other two areas.


Table 6.-Comparative abundance of song birds on study areas.

Total No. Total No. Av. Species Av. Individuals
Species Individuals per Trip
Pre-treatment
Area 1 110 7,498 35.20 220
2 120 11,083 38.40 325
3 115 17,243 40.70 510
Post-treatment
Area 1 109 8,621 34.60 257
2 113 17,040 37.90 592
3 108 39,606 40.40 1,181
% change
Area 1 -1.00 +15.00 -1.70 +16.00
2 -6.00 +54.00 -1.37 +55.00
3 -6.00 +129.00 -0.70 +132.00






Since these species are insectivorous, it is possible that the de-
crease in numbers was due to the effect of the insecticide upon
the food supply, i.e., the resulting food shortage, forcing them to
leave the area. The kill of insects on the area was essentially
complete, especially among the terrestrial species, immediately
following treatment. It is logical to assume that some of the
insectiverous species of birds were forced to find a source of
food outside the area during this period. No evidence of bird
mortality on the areas was noted. Concerted efforts to find dead
birds following treatment were unsuccessful.

Summer Quail and Dove Call Counts
It was felt at the beginning of the study that information
concerning the breeding quail and dove population on the areas
would be of considerable value. There was need for a sampling
study that would indicate the population density of these birds
on each area or population fluctuations that might occur between
areas during the course of study. Investigators in various states
have, for several years, used the whistling-cock count as an
indicator of the breeding quail populations and the dove cooing-
call count as an indicator of breeding dove populations.
The plan employed consisted of traveling roads within or
surrounding the areas, stopping at one-half mile intervals, listen-
ing for five minutes, and recording the number of quail "bob-
whiting" and the number of doves "cooing". Birds seen while
parked or driving between stops were also recorded. The time
of driving between stops was two minutes. Eleven stops were
made per trip on each of Areas 1 and 3. Nine stops were made
per trip in Area 2. Counts were conducted at 10-day intervals
during the months of May, June, July, and August two years
prior to treatment and two years following treatment. Each
count began at sunrise. Birds heard and seen on land adjacent
to the areas were also recorded. It was thought this informa-
tion might detect ingress and egress in the event movements
should occur.
Results are shown in Table 7. Counts are broken down to
show the average per stop on each area for the two years
prior to treatment and the two years following treatment.
There was an increase in the number of calls during the
two post-treatment years over the two pre-treatment years on
all the areas. The slight drop in the quail call count in 1962 on
Areas 1 and 2 is due to the termination of calling at an earlier
date in August than in former years. The increase in the breed-
ing population of birds on Area 1 during the post-treatment







Table 7.-Comparative quail


and dove call counts on study areas.
Average per Stop


Area 1 Quail Heard Quail Seen Dove Heard Dove Seen
1959* .77 .07 .29 .02
1960* .79 .07 .14 .05
1961** 1.30 .08 .33 .07
1962** .98 .33 .44 .08
Area 2
1959 .99 .03 .22 .08
1960 1.60 .06 .25 .03
1961 1.67 .08 .40 .09
1962 1.22 .13 .37 .13
Area 3
1959 .95 .06 .55 .27
1960 1.25 .04 .60 .30
1961 1.25 .10 .90 .30
1962 1.36 .08 .60 .49
:Pre-treatment counts.
**Post-treatment counts.

period over the pre-treatment period indicates that the treat-
ment had no effect on the breeding population.

Wintering Quail Population Survey
The primary reason for conducting winter quail census on
the areas was to learn what effect the treatment might have
upon production on Area 1. One pre-treatment census during
the winter of 1959-60 and two post-treatment census during the
winters of 1960-61 and 1961-62 were conducted.
Method of censusing was by the covey whistle call count.
This involved listening for individual coveys to whistle upon
leaving the roost at daybreak and marking their locations on a
map. It was necessary to be at a desired listening station 30
minutes before sunrise. Approximately 25 or 30 minutes before
sunrise a few of the birds in each covey will whistle before
leaving the roost. Whistling continues for a period of about one
minute. During that period every covey within audible range
can be mapped. Audible range on clear, calm mornings is ap-
proximately three-eighths mile. The listening station for any
given morning would be located approximately three-fourths
mile from the previous listening station. It is believed that this
method was accurate and that none of the coveys were counted
more than once.
The number of coveys located by this method on each area
is shown in Table 8.
The number of wintering coveys on each area remained essen-
tially the same throughout the study. The coveys found with


~






Table 8--Winter coveys on each area.

Winter Area 1 Area 2 Area 3

1959-60* 9 9 10
1960-61** 10 11 12
1961-62** 9 9 11

*Pre-treatment
::: Post-treatment

bird dogs on this area during the winters following treatment
showed them to be of normal size. Six birds were collected from
different coveys during the first winter following treatment and
sent to the U. S. Fish and Wildlife Service's Patuxent Wildlife
Research Center at Laurel, Maryland, for chemical analysis.
Although the birds were found to contain heptachlor expoxide
at levels that had caused 40% decreased reproduction of birds
in captivity, no evidence of decreased reproduction was noted
on the treated area.
None of the studies showed any substantial effect of the
treatment upon bird and mammal populations on the treated
area. Also no effect of the ants themselves on bird and mam-
mal populations was noted.

SUMMARY AND CONCLUSIONS

In the spring of 1959, the Florida Agricultural Experiment
Station, the Game and Fresh Water Commission, and the Plant
Industry Division entered into a cooperative project agreement
to obtain quantative data on the effects of the imported fire
ant (Solenopsis saevissimu richteri, Forel) and of the large
scale eradication programs on other forms of wildlife. Three
ecologically similar areas, each approximately 1,280 acres in
size, were selected in northwest Florida for this study. Areas 1
and 2 were heavily infested with fire ants. Area 3 was not in-
fested. Preliminary sampling studies for one year were em-
ployed to determine, as nearly as possible, the normal populations
of wildlife forms on these areas. The study was designed to
bring out any effect the fire ants themselves had on the popula-
tions of other wildlife forms as well as any population changes
induced by the insecticide treatment against the fire ants.
Area 1 was treated by airplane, using 1.25 pounds of techni-
cal heptachlor in granular form per acre, in September 1960. All
cropland, fallow fields, pasture land, and open timber land were






treated, which amounted to approximately 507% of the area.
Area 2 was infested but not treated and was used to study the
effects of the fire ants upon other forms of wildlife. Area 3 was
not infested with fire ants and was designated the check or con-
trol area.
Arthropod and annelid populations were sampled by five
methods as follows: 1. alcohol pitfalls, 2. soil samples, 3. litter
samples, 4. sweet net samples, and 5. light traps. From 4 to 48
samples were taken in each area, each month, depending upon
the method of sampling, for 12 months prior to treatment of
Area 1, and the same number were taken in a similar manner
in each area for 48 months following treatment of Area 1.
The indicator species reported in this paper were severely
reduced in numbers immediately following treatment and, in
most cases, remained at a low level for several months before
they began increasing in numbers. Some forms were more
affected than others. In most instances these forms reached
normal population counts within 12 months; however, it took
as long as 19 months for some forms to reach normal pre-treat-
ment levels.
The imported fire ants were eradicated from the treated area
within one month following application of the insecticide. This
area remained free of fire ants for a period of 22 months, after
which they began to slowly reappear. It took 48 months fol-
lowing treatment for the fire ants to reach the number of active
colonies that were on it prior to treatment. The fire ants had
no effect on other arthropod or annelid populations.
Sampling techniques were employed in studying mammal
and bird populations that would indicate any change that might
occur on any of the three areas. These were 1. summer small
mammal, 2. large mammal, 3. songbird, 4. summer quail and
dove breeding population, and 5. wintering quail population.
None of these studies showed any marked effect of the treat-
ment upon either bird or mammal populations on the treated
area. The ants had no apparent effect upon bird and mammal
populations.







LITERATURE CITED

1. Baker, W. L. 1946. DDT and earthworm populations. Econ. Entomol
39(3) :404-405.
2. Barker, R. J. 1958. Notes on some ecological effects of DDT sprayed
on elms. Wildlife Management. 22(3) :269-274.
3. Couch, L. K. 1946. Effects of DDT on wildlife in a Mississippi River
bottom woodland. Trans. 11th N. Amer. Wildlife Conf.:323-329.
4. Doane, Charles C. 1962. Effects of certain insecticides on earthworms.
Econ. Entomol. 55(3) :416-418.
5. Fichter, Edson. 1941. Apparatus for the comparison of soil surface
arthropod populations. Ecology 22(3) :338-339.
6. Hoffman, C. H., H. K. Townes, H. H. Swift, and R. I. Sailer. 1949.
Field studies on the effects of airplane applications of DDT on forest
invertebrates. Ecological Monographs 19:1-46.
7. Rogers, I. 1948. The effects of DDT on a bird population. Condor.
50(2) :89-90.
8. Rosene, W. R., Jr. 1958. Whistling-cock counts of bobwhite quail on
areas treated with insecticide and on untreated areas, Decatur County,
Ga. Proc. 12th Ann. Conf. S. E. Assoc. of Game and Fish Com.:240-
244.
9. Springer, P. E. and J. R. Webster. 1951. Biological effects of DDT
applications on tidal salt marshes. Mosquito News. 2(2) :67-74.
10. Stickel, George. 1949. Effects of DDT dust on wildlife. Amer. Midi.
Nat. 42(1) :228-237.









ACKNOWLEDGMENTS

These studies could not have been conducted successfully without the
assistance of a number of people. The authors wish to acknowledge the
assistance given by the following: Drs. A. N. Tissot, E. G. Kelsheimer,
L. C. Kuitert and M. H. Muma of the Florida Agricultural Experiment
Stations and Harold Denmark, Plant Industry Division, State Department
of Agriculture, who made helpful suggestions and selected the study areas
as well as helped with the identification of arthropod specimens; and T. J.
Spilman, Insect Identification and Parasite Introduction Research Branch,
USDA, ARS, and 0. L. Cartwright, Associate Curator, Department of
Insects, U. S. National Museum who helped identify arthropod specimens.
The authors also wish to acknowledge the help given by Dr. Henry
M. Stevenson, Zoology Department, Florida State University, Edwin L.
Tyson, Graduate Student in Zoology, Florida State University, and Donald
D. Barbee, student in Zoology, Florida State University, in conducting this
study. Appreciation is also extended to James M. Stanely, Agricultural
Engineer, USDA, ARS, and E. S. Holmes, formerly Assistant Agricultural
Engineer, University of Florida.







LITERATURE CITED

1. Baker, W. L. 1946. DDT and earthworm populations. Econ. Entomol
39(3) :404-405.
2. Barker, R. J. 1958. Notes on some ecological effects of DDT sprayed
on elms. Wildlife Management. 22(3) :269-274.
3. Couch, L. K. 1946. Effects of DDT on wildlife in a Mississippi River
bottom woodland. Trans. 11th N. Amer. Wildlife Conf.:323-329.
4. Doane, Charles C. 1962. Effects of certain insecticides on earthworms.
Econ. Entomol. 55(3) :416-418.
5. Fichter, Edson. 1941. Apparatus for the comparison of soil surface
arthropod populations. Ecology 22(3) :338-339.
6. Hoffman, C. H., H. K. Townes, H. H. Swift, and R. I. Sailer. 1949.
Field studies on the effects of airplane applications of DDT on forest
invertebrates. Ecological Monographs 19:1-46.
7. Rogers, I. 1948. The effects of DDT on a bird population. Condor.
50(2) :89-90.
8. Rosene, W. R., Jr. 1958. Whistling-cock counts of bobwhite quail on
areas treated with insecticide and on untreated areas, Decatur County,
Ga. Proc. 12th Ann. Conf. S. E. Assoc. of Game and Fish Com.:240-
244.
9. Springer, P. E. and J. R. Webster. 1951. Biological effects of DDT
applications on tidal salt marshes. Mosquito News. 2(2) :67-74.
10. Stickel, George. 1949. Effects of DDT dust on wildlife. Amer. Midi.
Nat. 42(1) :228-237.









ACKNOWLEDGMENTS

These studies could not have been conducted successfully without the
assistance of a number of people. The authors wish to acknowledge the
assistance given by the following: Drs. A. N. Tissot, E. G. Kelsheimer,
L. C. Kuitert and M. H. Muma of the Florida Agricultural Experiment
Stations and Harold Denmark, Plant Industry Division, State Department
of Agriculture, who made helpful suggestions and selected the study areas
as well as helped with the identification of arthropod specimens; and T. J.
Spilman, Insect Identification and Parasite Introduction Research Branch,
USDA, ARS, and 0. L. Cartwright, Associate Curator, Department of
Insects, U. S. National Museum who helped identify arthropod specimens.
The authors also wish to acknowledge the help given by Dr. Henry
M. Stevenson, Zoology Department, Florida State University, Edwin L.
Tyson, Graduate Student in Zoology, Florida State University, and Donald
D. Barbee, student in Zoology, Florida State University, in conducting this
study. Appreciation is also extended to James M. Stanely, Agricultural
Engineer, USDA, ARS, and E. S. Holmes, formerly Assistant Agricultural
Engineer, University of Florida.




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