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THESIS

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31293 00892 7349

This is to certify that the

thesis entitled

A survey of ants as candidates for potential biological
control of pear psylla (Cac0psylla piricola (Foerster))
in Michigan.

 

presented by

Dwi Suryanto

has been accepted towards fulfillment
of the requirements for

Master's Entomology

degree in

f:§. James ~

Major professor

 

 

 

 

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A SURVEY OF ANTS AS CANDIDATES FOR POTENTIAL BIOLOGICAL
CONTROL OF PEAR PSYLLA (cacopsyllalpyricola (Foerster))

IN MICHIGAN

by

Dwi Suryanto

A THESIS

Submitted to
Michigan State University
in partial fulfillment of the requirements

for the degree of

MASTER OF SCIENCE

Department of Entomology

1993

ABSTRACT
A SURVEY OF ANTS AS CANDIDATES FOR POTENTIAL BIOLOGICAL

CONTROL OF PEAR PSYLLA (Cacqpsylla pyricola (Foerster))
IN’MICHIGAN

BY

Dwi Suryanto

Ground bait, tree bait, pitfall traps, soil samples
Berlese funnel extractions were used to sample ant species in
pear orchards under different pesticide regimes. Eleven
species of ants were captured in pear orchards during 1991-
1992. Lasius neoniger and Prenolepis imparis were the most
abundant ants in the pear orchard. crematogaster cerasi may
have potential as a candidate for biological control of pear
psylla. Some ant populations were significantly affected by
pesticides, but it was not a consistent difference throughout

the season.

"The pest has been developing resistance to pesticides
faster than new ones can be registered, and there are few

options left" (Geraldine Warner 1991).

"A principal difference between human beings and ants is
that whereas we send our young men to war, they send their

old ladies" (Bert Holldobler & Edward O. Wilson 1990)

DEDICATIONS

To my parents and my wife

ACKNOWLEDGEMENTS

I wish to express my deepest appreciation and sincere
thanks to my major professor, Dr. James W. Johnson, for his
guidance, patience and support throughout my master's program,
and for giving me the opportunity to learn about the basic of
biological control.

I am grateful to Dr. Catherine Bristow of the Department
of Entomology for her suggestions and corrections.

A.special note of thanks is due to the other member of my
guidance committee, Dr. Donald 0. Straney of the Department of
Zoology, for helping me identifying the ants.

I would also thank to Trevor Nichols Research Station's
workers. Without their help, this research would not have been
completed.

I have enjoyed the interaction and aid from the marvelous
students and friends, John C. Wise, Saturnino Nunez, Robert
Kriegel and Grzegorz Krawczyk.

To my wife, Dyah Ratna Budiani, thank you for helping me
finishing my thesis.

Finally; I would also like to thanks to mngovernment and
the authorities of the HEDS Project for economic support and
confidence.

iii

TABLE OF CONTENTS

ACKNOWLEDGEMENTS. . . . . . . . . . . . . . . . . . . . . .ii
ABSTRACT. . . . . . . . . . . . . . . . . . . . . . . . . iii
TABLE OF CONTENTS . . . . . . . . . . . . . . . . . . . . .iV
LIST OF TABLES. . . . . . . . . . . . . . . . . . . . . . .Vi
LIST OF FIGURES . . . . . . . . . . . . . . . . . . . . .Viii
INTRODUCTION. . . . . . . . . . . . . . . . . . . . . . . . 1
LITERATURE REVIEW . . . . . . . . . . . . . . . . . . . . . 4

Previous Research on Chemical and Cultural Control of
Pear Psylla. . . . . . . . . . . . . . . . . . . . . . 4
Previous Research on Biological Control and Plant
Resistance . . . . . . . . . . . . . . . . . . . . . . 6

Ants as Potential Pear Psylla Control Agents . . . . . 8

MATERIALS AND METHODS . . . . . . . . . . . . . . . . . . .11
Environmental Data . . . . . . . . . . . . . . . . . .15
Ground Sampling. . . . . . . . . . . . . . . . . . . .15
Tree Sampling. . . . . . . . . . . . . . . . . . . . .16
Pitfall Traps. . . . . . . . . . . . . . . . . . . . .16
Berlese Soil Sampling. . . . . . . . . . . . . . . . .16
Direct Observation . . . . . . . . . . . . . . . . . .16

RESULTS AND DISCUSSIONS . . . . . . . . . . . . . . . . . .18
Environmental Data . . . . . . . . . . . . . . . . . .18

iv

The Ant Species in the Orchard
Lasius neoniger.
Prenolepis imparis
Crematogaster cerasi
Other Ants

CONCLUSIONS
References.
Appendix 1.

Appendix 1.1.

.18

27

46

48

49

.54

.56

.62

.63

Table

Table

Table

Table

Table

Table

Table

Table

Table

Table

10.

LIST OF TABLES

Spray schedule for 3 blocks of pear in 1991

and 1992 . . . . . . . . . . . . . . . . . . . .12
Air temperature and precipitation during ground
bait sampling in 1991 and 1992 . . . . . . . . .19

Air temperature and precipitation during tree

bait sampling in 1991 and 1992 . . . . . . . . .20
Soil (15 cm ) and air temperature range during
pitfall traps in 1991 and 1992 . . . . . . . . .21
Soil temperature (°C) during soil sampling . . .22

. Number of species in the pear orchard. . . . . .23

Total captured individual of the species in the
pear orchard based on trap types . . . . . . . .28
Total captured individual of the species in the
pear orchard based on blocks . . . . . . . . . .29
Direct observation of ant abundance and

activity . . . . . . . . . . . . . . . . . . . .30
Comparison of ant captures on three different
ground baits, 1991 and 1992 (data transformed

as x+0.5, means followed by same letter not

significantly different, LSD, p=0.05). . . . . .31

vi

Table

Table

Table

11.

12.

13.

Comparison of ant
in West, Central,
(data transformed
same letter not
p=0.05).

Comparison of ant
in West, Central,
(data transformed
same letter not
p=0.05).

Comparison of ant
in West, Central,
(data transformed
same letter not

p=0.05).

captures in ground bait traps
and East block in 1991 and 1992
as JETUTS, means followed by
significantly different, LSD,
.32
captures in tree bait traps
and East block in 1991 and 1992
as V§TOT§, means followed by
significantly different, LSD,
.33
captures in pitfall traps
and East block in 1991 and 1992
as VRTUTE, means followed by
significantly different, LSD,

.34

vii

Figure

Figure

Figure

Figure

Figure

Figure

Figure

Figure

6.

7.

8.

LIST OF FIGURES

Location of treatments, traps, and replications
in 1991. . . . . . . . . . . . . . . . . . . . .13

Location of treatments, traps, and replications

in 1992. . . . . . . . . . . . . . . . . . . . .14
Monthly temperature in 1991 and 1992 . . . . . .24
Montly precipitation during 1991 and 1992. . . .25

Total individuals of L. neoniger, P. imparis,

and C. cerasi captured with ground baits, tree
baits, pitfalls, and Berlese extraction in 1991
and 1992 (untransformed data) from all trap
types. . . . . . . . . . . . . . . . . . . . . .26
Numbers (transformed VEIBT§> of L. neoniger and
P. imparis captured in pitfall traps across West,
Central, and East blocks in 1991 . . . . . . . .36
Numbers (transformed VEIOTS) of M3 emeryana and
C. cerasi captured in pitfall traps across West,
Central, and East blocks in 1991 . . . . . . . .37
Numbers (transformed VEIOTS) of L. neoniger and
P. imparis captured in pitfall traps across West,

Central, and East blocks in 1992 . . . . . . . .38

viii

Figure

Figure

Figure

Figure

Figure

Figure

Figure

10.

11.

12.

13.

14.

15.

Numbers (transformed J§:OT§) of M1 emeryana and
C. cerasi captured in pitfall traps across West,
Central, and East blocks in 1992 . . . . . . . .39
Numbers (transformed W) of captured L.
neoniger, P. imparis, and C. cerasi in the ground
bait traps in 1991 (data from West block). . . .40
Numbers (transformed VETUTE) CHE captured L.
neoniger, P. imparis, and C. cerasi in the ground
bait traps in 1992 (data from Central block) . .41
Numbers (transformed (EGO—.6) of captured L.

neoniger, P. imparis, and CK cerasi in the tree

bait traps in 1991 (data from West block). . . .42
Numbers (transformed s/x+0.5) of captured L.

neoniger, P. imparis, and C. cerasi in the tree
bait traps in 1992 (data from Central block) . .43

Numbers (transformed W) of captured L.
neoniger, P. imparis, and C. cerasi in the
pitfall traps in 1991 (data from West block). . 44

Numbers (transformed (Sic—+33) of captured L.
neoniger, P. imparis, and C. cerasi in the
pitfall traps in 1992 (data from Central

block) . . . . . . . . . . . . . . . . . . . . .45

ix

INTRODUCTION

INTRODUCTION

After its introduction from Europe into Connecticut in
1832, pear psylla, Cacopsylla,pyricola (Foerster) (Homoptera:
Psyllidae), spread over pear-growing regions and became the
key pest of pear (Pyrus communis L.) in the United States and
Canada (Westigard et al. 1979, Brunner & Howitt 1981,
Westigard & Moffitt 1984, Fye 1985, Butt et al. 1989). It is
also a very important pest in pear-growing regions in the
world (Westigard & Moffitt 1984, Quarta & Puggioni 1985,
Armand et al. 1991).

Pear is the primary host of pear psylla (Brunner & Howitt
1981, Westigard.et al. 1979). Many plants, such.as chess grass
(Bromus tectorum L.), climbing night-shade (Solanum dulcamara
L.) and peach (Prunus persica (L)), have been identified as
transitory hosts of pear psylla (Wilde 1966, Ullman & McLean
1988), but are not suitable for reproduction (Kaloostin 1970,
Ullman & McLean 1988, Horton & Krysan 1990).

Pear psylla nymphs can kill pear trees by injecting a
toxicogenic substance or introducing a micoplasm-like organism
(Westigard et al. 1979). In the process of feeding, pear
psylla produces honeydew, a clear sugary liquid, which may
drop onto fruit, leaves, and bark. Honeydew is a suitable

substrate for sooty mold to grow, which blackens the leaves

2
and fruit surfaces and reduces market acceptability (Westigard
et al. 1979, Brunner & Howitt 1981). Reduced size of fruit in
following years may occur if numerous pear psylla excessively
consume water and nutrients from trees (Brunner & Howitt
1981) .

Pear psylla have mainly been controlled with insecticides
(Burts 1983, Westigard et al. 1986, Poulson & Akre 1991a).
However, pesticides may cause environmental problems,
resistance and pest resurgence, and produce undesirable side
effects on.non-target organisms such.as natural enemies of the
pest (Harries & Burts 1965, Riedl et al. 1981, Burts 1988).
These problems, coupled with growing consumer demand for
pesticide-free produce have increased emphasis on alternative
pest control tactics, such as biological control, resistant
cultivars, and cultural practices (Burts 1983, Quame 1984,
Poulson & Akre 1991b).

Biological control of pear psylla was first noted by
Slingerland (1896). He saw' that the jpredators, Chrysopa
oculata Say and Adalia bipunctata (L.) feed on pear psylla
eggs, nymphs and adults. The most effective biological
controls of pear psylla were reported by Westigard et al.
(1968) and Poulson & Akre (1991a).

Ants as biological control agents show many advantages
over other biocontrol organisms and.may play an important role
in controlling pests in some situations (e.g., Poulson & Akre

1991a, Timti 1991, Way & Khoo 1992). However, their use in

3
North American agriculture is still undeveloped (Poulson &
Akre 1991b).
The objectives of this research were:
1. to identify ant species common in pear orchards,
2. tc>determine the most important ant species for potential
biological control agents of pear psylla,
3. to record ant population.patterns during the season, and
4. to evaluate the effects of insecticides on the ant

populations in the pear orchard in Michigan.

LITERATURE REVIEW

LITERATURE REVIEW

Previous Research on Chemical and Cultural Control of Pear
Psylla

Chemical of control pear psylla has been the major
control strategy in commercial pear-growing regions.
Insecticides used after the first appearance of pear psylla in
Washington included nicotine, parathion, dieldrin, and
azinphos—methyl. In California, organophosphates such as
malathion, parathion, trithion, and ethion were the first used
insecticides for pear psylla control. Next was azinphos-methyl
combined with light petroleum oils. This insecticide
controlled the pest for nearly 14 years but in Washington and
Oregon when this insecticide was sprayed without oils, it only
controlled pear psylla for 4-5 years (Riedl et al. 1981).
Growers did not use this oil combination because of the risk
of fruit injury (Burst 1983). There are now three to six
insecticide applications used annually in Washington,
California and. Oregon. Fenvalerate and. oxythioquinox: are
sprayed before bloom and amitraz after bloom (Burts 1988).
Probably the most commonly insecticide used in Ontario, Canada
is azinphos-methyl, although endosulfan, phosalone, and

phosmet are also applied (Hagley & Simpson 1983).

5

Previous research indicated most of the insecticides
caused insecticide resistance (Harries & Burt 1965), which
varied among regions and subregions (Tabashnik et al. 1990).
After only several years of application, pear psylla had
become resistant to several insecticides such as nicotine,
dieldrin and azinphos-methyl (Harries & Burts 1965, Rield et
al. 1981). Riedl et al. (1981) reported that resistance
develops because pear psylla does not have other wild hosts,
does not disperse widely, has a high fecundity and produces
several generations a year.

Resurgence in pear psylla populations have also been
reported. Suppression programs using permethrin caused pear
psylla resurgence two*weeks after harvest (Riedl et al. 1981).
This also occurred in amitraz applications at the peak of
second generation, although it gave good initial control
(Burts 1983). Resurgence of other pests such as phytophagous
mites and grape mealybug was likely due to lack of phytoseiid
mites and other predators (Rield et al. 1981).

Organophosphates and.pyrethroids used to control codling
moth flared pear psylla populations by killing their predators
(Hagley & Simpson 1983). The decline of pear psylla
populations in untreated insecticide plots was reportedly
related to abundance of natural enemies (Burts 1983, Hagley &
Simpson 1983, Westigard & Moffitt 1984).

Insect growth regulators have been investigated to

maintain pear psylla population. These insecticides provide

6
good control in research trials, but they are not yet
registered (Westigard et al. 1979, Krysan 1990).

Cultural control programs of pear psylla have been
investigated by several workers. Burts (1983) found that
summer pruning of water sprouts and terminal shoot growth
could lower'pear‘psylla.population4 He also believed that soap
compounds might have potential for management of pear psylla,
but speculated that this technique may cause serious fruit
russetting.

Since pear psylla.prefers young succulent tissue, the use
of plant growth regulators may be an important control tactic
in regulation of pear psylla population (Westigard 1974,
Westigard et al. 1980, Krysan 1990, Warner 1991). Studies
conducted in southern Oregon showed that pear psylla eggs and
nymphs were reduced by 50 percent and.honeydeW'damage to fruit

by 75 percent (Westigard et al. 1979).

Previous Research on Biological Control and Plant Resistance

The predators of pear psylla included Coleoptera,
Diptera, Hemiptera and Neuroptera (Philogene & Chang, 1978).
Most predators prefers eggs and nymphs of pear psylla (Madsen
& Wong 1964, Philogene & Chang 1978, Westigard 1979).

Madsen & Westigard (1963) and Madsen & Wong (1964) noted
that the anthocorid bug, (Anthocoris antevolens White), and
lacewing, (Chrysopa oculata Say), were predators of psylla and

could reduce the population by 80%. Philogene & Chang (1978)

7

found that A. antevolens and A. nemoralis were apparently
specific predators of pear psylla. Fye (1985) recorded other
major pear psylla predators including a myrid, (Deraeocoris
brevis (Uhler)), a brown lacewing, (Hemorobius ovalis
Carpenter), and a moderate array of spiders. Although many
predators have been found, the effectiveness of predation
varies greatly with the locality, climatic conditions, density
of the prey, and presence of natural enemies (Philogene &
Chang 1978).

Parasitoids have also been reported in reducing pear
psylla populations. Philogene & Chang (1978) noted 13 species
of the parasitoids attacked on pear psylla. One of the most
effective parasitoids was ZTechnites insidiosus (Crawford)
(Philogene & Chang 1978), but this parasitoid was greatly
affected by hyperparasitism and application of insecticides
(Westigard et al. 1968).

The genus Pyrus contains 20 to 25 species of pear. Only
three are commonly cultivated for their fruit (Westigard et
al. 1979). Some plant breeding programs for pear have been
developed to protect pear trees from pear psylla attacks.
Quame (1984) rated 46 pear cultivars for pear psylla
infestations. Ten.cultivars had.IOW'levels of infestation, the
others had.moderate and.high level of infestation. Butt et al.
(1989) showed.that Bradford was resistant, Barlett and NY10352

were susceptible and moderately resistant respectively. They

8
also noted that pear psylla development and feeding behavior

were negatively affected by pear cultivars.

Ants as Potential Pear Psylla Control Agents

Ants have been known either as beneficial insects or
pests, but their importance certainly lies somewhere between
the two extremes (Risch.& Carroll 1982, Way & Khoo 1992). Ants
act as herbivores, seed predators, dispersal agents,
scavengers, modifiers of soil structure, nutrient cycling
agents, plant pollinators and mutualists in many ant—plant
associations (Risch & Carroll 1982, Adenuga & Adeboyeku 1987) .

As agricultural and urban pests, ants contribute to
economic losses by feeding on plants or other materials
(Knight & Rust 1990). They may attack beneficial insects
(Nechols & Seibert 1985, Tedders et al. 1990). To defend their
colonies against live stock, man, and other animals or even
non-living material they may inject venom that causes serious
health problems or even death (Lofgren et al. 1975, Wd.
Eichler 1990).

Ant-plant associations have been investigated by many
researchers (e.g. Nechols & Seibert 1985, Adenuga &.Adeboyeku
1987, Dreisig 1988). Many plants having extrafloral nectaries
take advantage of ants destroying injurious herbivores and
weed competitors (Holldobler & Wilson 1990). Holldobler &
Wilson (1990) listed ants that have direct association with

plants.

9

A good example of ant-plant indirect association is ant-
homopteran symbiosis. This symbiosis has been recorded since
the Oligocene (Wheeler 1914). Most of them collect secretions
from homopterans, but may consume the homopterans if
carbohydrate supply exceeds colony demand as showed by wood
ants (Sudd & Franks 1987).

Ants as beneficial insects have been used as biological
control agents through the centuries. The first practical
insect biological control program used ants (van den Bosch et
al. 1982, Poulson & Akre 1991) . Ancient Chinese agriculturists
employed ants as effective predators in reducing the numbers
of leaf-feeding insects in citrus (van den Bosch et al. 1982,
Poulson & Akre 1991). Medieval date growers in Arabia also
used ants as a biological control agent which were transported
from nearby mountains (van den Bosch et a1. 1982).

As social predators, ants exhibit some features that
enhance their ability' and. efficiency' as foragers. Their
ability to search for prey along with their communication and
social system makes possible the integrated raid of hundreds
or thousands of ants in which killing a large prey becomes
much easier (Sterling et al. 1984, Holldobler & Wilson 1990).
Some predatory ants react quickly to the increasing of prey
density (Way & Khoo 1992).

Individual ability to capture prey is related to prey
size and associated with the distance of the ant's nest

(Tilman 1978, Godfrey et al. 1989). Green & Sullivan (1950)

10
proved that COmponatus herculeanus ligniperdus (Latrielle.)
and Formica fusca L. were enable to effectively control
lepidopteran larvae. Foraging group of Pheidole.morissi Forel
and P. dentata Mayr are able to captured 4 to 5 medium sized
larvae of velvetbean caterpillar. These species may play an
important rule on reducing velvetbeen caterpillar population
(Godfrey et al. 1989). Other abilities that ants possess are
to locate cryptic prey (Sterling et al. 1984), to travel to an
area 7-10 m away (Godfrey et al. 1989, Poulson & Akre 1991b)
and up to 9 m in height from its nest (Tedders et al. 1990).
These features are among the advantages of choosing ants as
biological control agents. Another important factor to
consider is the relative simplicity of conserving ant

populations (Poulson & Akre 1991a).

MATERIALS AND METHODS

11

MATERIALS AND METHODS

The study was conducted in a commercial pear orchard near
Fennville, Allegan Co, MI. The orchard was divided into 3
blocks (West, Central and East block) (Figure 1 & 2). The West
and Central blocks were a 1.62 ha standard pesticide treatment
blocks (Table 1), and the East block was a 0.81 ha codling
moth pheromone disruption block, utilizing Isomate-C
dispensers (Pacific Biocontrol, Ltd.) at a rate of 1000/ha.
The East block was separated from the two other blocks by a
three row block (approximately 0.5 ha) of apples.

Ground bait traps, tree bait traps, pitfall traps and
soil samples were used to collect ants. Samples were taken
biweekly (mid-July to the first week of October in 1991; last
week of June to the last week of September in 1992) from 7-9
aniand.4-6jpmu Tuna-flavored.cat-food.(protein), lard (lipid),
and grape jelly (carbohydrate) were used as baits in the
ground and tree bait traps. The baits were randomly placed
within stations. Ten trees in each.treatment block were chosen
randomly using random numbers for each type of trap (pitfall,
tree bait, ground bait). The samples were taken from the same
sampling trees in both years except in the East block (Figure
2). Collected ground and tree traps were brought to the

laboratory and placed in a refrigerator to immobilize ants

12

Table 1. Spray schedule for 3 blocks of pears in 1991 and

1992.
Blocks Pesticides Dates
1991 1992
West azinphos-methyl 5/10/91;5/31/91; 7/31/92; 8/8/92
(Guthion SOWP) 6/17/91;7/1/91;
7/23/91;8/2/91
ferbam 6/17/91;7/1/91 4/30/92;5/12/92
(Carbamate 76WDG)
dicofol 5/10/91 5/7/92;/5/19/92
(Kelthane 35WP)
amitraz - 6/8/92;7/6/92
(Mitac 1.5EC)
Center azinphos-methyl 5/10/91;5/31/91; 7/31/92; 8/8/92
(Guthion SOWP) 6/17/91;7/1/91;

7/23/91;8/2/9l
ferbam 6/17/91;7/1/91 4/30/92;5/12/92
(Carbamate 76WDG)
dicofol 5/10/91 5/7/92;/5/19/92
(Kelthane 35WP)
amitraz 5/29/91;6/24/91 -
(Mitac 1.5EC)

East avermectin 5/14/91 5/26/92
(Agrimec 0.5EC)

ferbam 6/17/91;7/1/91 4/30/92;5/12/92
(Carbamate 76WDG)

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*{KxNKKK‘KK‘KKx'KK-{O'K-K - g “HG-0'2
xxx «oxx xxxoxxxx «xxx ggtgg
xxxxx-«xxxx «{xxxxxxxx “_ 56:5
xxox xxxxxxar «KXOKx xx 8 *,_OX

In 1991

traps and replications

Location of treatments,

Figu'e 1.

 

 

14

 

 

mt i ng d i sr upt ion treatment

 

 

 

 

 

 

 

xx-xx+<x¢<xx-xx xx xx-xx xx xx xx
-oxx xxxo-—xxxxxxxx x"-xx
_ x-xx xx xx-xx inrx'“-x - ox x xx x
o
g b x x-x-'ox+<xucxx-xx x ooupxx-xx-xx
C
c
g (8 x xx xx-xxirxx xO-x 0 xx xt) x
u
8 xxxxx-xx-xxxxx-oxxxxxxx-xx
L
H " xoxxrx xxoxxxxxx-xxxxo
o
L "xit x‘K o it xxx 00*
u
23 xxoxxx—xxox-x xxxx xxxx-x
H o—
W 2 x-xx xx-xxit x-xx xx
m x-xx‘xx-xx-xx-xxi<xx-xx
o
-' xx-xxa:xx-xx-xx+:xx«xx
g l >Z
xx-xxirxx‘xx-xxicxx-xx
x {*iIKx m
xx-xxitxx‘xxx-xx-xxx xx 03%
xxxxxxxxxxx xxxx i( x QL
(DID-H
x-xx x-xx-xxirx-x * *x x-xx (1L
(UHH
xx-xxirxx-xxx xx-xx xx xi(xx L _
HHIU
xxxxxx xxxxxxxx xx xx 8 _ED
xxowxx—xxxxxxxx-xoxx x 8 mEDE
x--x xoxx x-ooxxxx xxxx 88:88
w I-
x ox-xx«—x-xx+<x xxaxxx —x ox- m- b‘1t35
*o‘X *K‘KO‘K-K"! XO'K'K K‘K g‘K'-OX

 

 

1992

In

traps and replications

Figure 2. Location of treatments,

 

 

15
before examination. All ants collected.in traps were preserved
in 70% alcohol.

To observe the effect of pesticide applications, data
frtm1ground.bait traps, tree bait traps regardless of the bait
and trap types, and pitfall traps were analyzed. The bait
preference tests used the West and the Central ground bait
trap data for 1991 and 1992, respectively.

Data were transformed to v7§1075) to make the data more
normally distributed and statistically analyzed with one-way
ANOVA followed by Least Significant Difference (LSD) test
(Sokal & Rohlf 1981). Except in Figures 3,4, and 5,

transformed data were presented in all graphs.

Environmental Data.

Air temperature, soil temperature, and precipitation
during sampling were obtained from a NOAA weather station at
the Trevor Nichols Research Station, Fennville, 3.2 km from

the research site.

Ground Sampling.

Three bait stations filled to the depth of approximately
Einmiof petridish.with tuna-flavored cat food, lard, and.grape
jelly in 100x15 mm petri dishes were set on the ground and 50-

100 cm from the tree under each of the ten chosen trees.

16
Tree Sampling.
Plywood cup holder, 38x8 cm with three 5—cm holes, were
wedged into an angle between two branches and secured with a
wire 1-1.5 m above ground level. The baits were placed in

three, 2-oz souffle cups.

Pitfall Traps.

Cups (12-cm diameter), coated with Fluon to prevent ants
from escaping, were filled with 150 ml 70% alcohol and buried
in the ground.under randomly selected trees and left for 48 h.
To protect the traps from mice or other animals, a Fluon-

coated screen (1/2 cm mesh) covered the traps.

Berlese Soil Sampling.

Five soil samples (25x25 cm) were randomly taken from
each block to a depth of 10 cm. The samples were placed into
paper bags and taken to the laboratory. Soil samples were
collected on August 18 and November 15 in 1991, and on.May 13,
August 11 in 1992.

The samples were extracted in Berlese funnels for 2

weeks. Ants were collected and preserved in 70% alcohol.

Direct Observation.
In addition to the collected samples, ants were hand-
collected using forceps and preserved for identification. Bi-

monthly' observations were taken. by *walking through test

l7
orchards looking for ants in trees for approximately one hour.
When found, ants were observed for variable time periods for

foraging behavior and psylla predation.

RESULTS AND DISCUSSIONS

18

RESULTS AND DISCUSSIONS

Environmental Data.

Temperatures (°C) were recorded during sampling times, 7-
9 am and 4-6 pm for ground (Table 2) and tree bait traps
(Table 3). Soil and air range temperatures (°C) were also
recorded during the 48 hour pitfall (Table 4). For soil
samples, temperatures were taken at a depth of 15 cm (Table
5). At the beginning of the study the temperatures increased
until late August in 1991 and until the second week of August
in 1992. Monthly average temperatures were generally higher in
1991 than those of 1992 (Figure 3).

August and June were the driest months in 1991 and 1992,
respectively. There was more rainfall in 1992 than in 1991

(Figure 4) .

The ant species in the orchard.

Eleven species of ants were found in the pear orchard
(Table 6). Captures varied greatly by trap types in some
species while others were found in samples from all trap
types.

All the population numbers increased about 2.1 times in
average while P. imparis decreased about 3.1 times in the

second year (Figure 5) . This ratio may be smaller because the

19
Table: 2..Air temperature and precipitation during ground.bait

sampling in 1991 and 1992.

Temperature(%fl Precipitation

Sample dates ---------------- (mm)/day.

 

Jul 15 16.36 26.33 0.00
Jul 29 16.56 19.33 12.24
Aug 12 14.25 27 0.00
1991 Aug 26 19.89 30.83 0.00
Sep 9 19.44 31.28 21.42
Sep 20 6 28 11 19 0 51
Oct 3 15 11 16 22 0 26
Jun 28 9 78 20 78 0 00
Jul 12 21.11 22 22 1 53
Jul 26 20 24.78 35.96
1992 Aug 9 21.22 29.44 0.00
Aug 23 17 26.55 0.00
Sep 20 4 89 18 78 4 34

Sep 27 12.77 13.38 10.20

20
Table 3. Air temperature and precipitation during tree bait

sampling in 1991 and 1992.

 

Temperature(%fl Precipitation
Sample dates ---------------- (mm)/day.
7-9 am 4-6 pm
Jul 16 18 29.22 0.00
Jul 30 15.03 22.55 0.00
Aug 13 15.44 26.33 0.00
1991 Aug 27 20.11 28.89 0.00
Sep 10 21.55 24.11 0.51
Sep 21 4.55 17.33 0.00
Oct 4 10.83 10.86 7.4
Jun 27 10.86 16.88 0.00
Jul 11 16.44 22.78 0.00
Jul 25 17.11 22.78 1.28
1992 Aug 8 19.33 23.89 50.02
Aug 22 12.42 26.11 0.00
Sep 5 14.11 24.72 0.00

21
Table 4. Soil (15 cm) and air temperature range during

pitfall trap in 1991 and 1992.

 

Sample dates 8011(°C) A1r(°C)
Jul 17-19 22.44 - 27.33 18.67 - 30.72
Jul 31- Aug 2 19.11 - 27.33 14.44 — 29.11
Aug 14-16 19.78 - 26.44 13.83 - 27.55
1991 Aug 28-30 23.33 - 28.67 19.55 - 32.72
Sep 11-13 18.66 - 22.44 13.61 - 23.33
Sep 18-20 12.94 - 18.88 5.94 - 16.22
Oct 2- 4 13.61 - 16.44 10.33 — 20.89
Jun 26-28 15.11 - 21.56 2.94 - 17.77
Jul 10-12 20.22 - 25.55 13.61 - 25.55
Jul 24-26 18 - 20.67 13.39 - 23.11
1992 Aug 7- 9 17.55 - 23.11 17.33 - 26
Aug 21-23 15.33 - 21.11 8.11 - 26.67
Sep 4- 6 16 22 - 20 67 7 06 - 26 89

22

Table 5. Soil temperature (°C) during soil sampling

Sample dates 15 mm depth

Aug 18, 1991 21.67

Nov 15, 1991 no data available
May 6, 1992 9.11

 

23

Table 6. Number of species in the pear orchard.

Species Ground Tree Pitfall Soil
Lasius neoniger Emery + + + +
Prenolepis imparis (Say) + + + +
Crematogaster cerasi (Fabricius) + + + -
Myrmica emeryana Forel + + + +
Tapinoma sessile (Say) + + + +
Solenopsis molesta (Say) + - + +
Fbrmica fusca (Say) + + + -
Fbrmica schaufussi Mayr + + + -
camponotus ferrugineus Linne - - + —
.Mbnomorium minimum (Buckey) + - + +
Ponera pennsylvanica Buckey - - - +
+ found

— not found

 

 

24

 

.Noa— 9:. 32. :- Ouaachanoa 25:02 .9 2:2...—

 

 

 

aaos .25.— ...3 [ml 38: as.» .58: IT
=3: .23.... .5! IT .395 .95... .82 lo!
5.32
«o0 new os< .2. c2.
_ . . . O
- u o
a. o.
A 3
fl
(TIL on
.. on
J: - on
on

 

 

 

«0 v OhaudbOQ-BOF

 

 

 

 

 

    
 
  

W ‘\\\\\\\\\\\\\\\\\\\\\\\‘

 

 

 

 

 

llllllllllllll

OOOOOOOOOOOOOOOO
OOOOOOOOOOOOOOO

 

- Precipitation (1901) m Preelpltatlon (1902)

ring

oipltation

thly pro

Figure

 

 

 

26

 

.39: as: =- 52. .83 3522.233
«so. use 30— ... nose-3x. coat-m ea 6.3:... 6:... .2. 6:...
2593 5.! cease-e 333 .0 a... 622:5 .1 cs :32. .4 he 0.2.220... .80... .0 2:2“.

«3. g 32 I

 

 

 

    

 

 

 

 

 

3930 .0 2.35.: .m teases: .4
E \ I .
i w
i o
.. o
i 0..
1 up
.. 3.
or

652.2... 23222.. .38

 

 

27
sampling time were different. Fellers (1989) saw that
subordinate species may avoid the dominants to reduce
interference.

Ants were more abundant in the standard pesticide
treatment blocks (West and Central blocks) (Table 8). P.
imparis was the most abundant ant in the orchard in the first
year of study. In the second year L. neoniger seemed to be
more abundant.

Three species, P. imparis, L. neoniger and C. cerasi,
were noticed probably the most important ants as candidates
for biological control agents of pear psylla. This is based.on
the data and direct observation on their preference tijrotein
bait trap, their abundance in the orchard, the fact that they
carried. psylla nymphs or other' prey' species, and their

foraging sites.

Lasius neoniger.

L. neoniger was one of most abundant species and was
captured in all types of trap. It was only exceeded in
number by Prenolepis imparis. This species is predominant in
more open sites (Traniello 1987). It may be beneficial in
term of biological control in apple orchards, but its
contribution is unknown (Goonewardene 1989). Direct
observation showed that this species carried psylla nymphs

(Table 9).

 

28

Table 7. Total captured individual of the species in the pear

orchard based on trap types.

Species Ground
1991 1992
L. neoniger 2939 4216
P. imparis 9619 4008
C. cerasi 26 695
ML emeryana 80 486
T. sessile 52 92
S. molesta 9 97
F. (fusca group) 12 229
F. schaufussi 0 1
C. ferrugineus 0 0
M2 minimum 10 247
P . pennsyl vani ca 0 0

Pitfall
1991 1992
2530 2440
3059 324
26 12
462 971
43 64
78 189
80 181
4 6
11 6
15 27
0 0

195

15

354

 

29
Table 8. Total captured individual of the species in the pear

orchard based on blocks.

Species West Central East

' 1991 1992 1991 1992 1991 1992
L. neoniger 1487 4360 3528 4322 708 1615
P. imparis 9238 2833 4301 1562 1515 506
C. cerasi 3 1 18 674 31 129
M3 emeryana 191 575 58 102 320 808
T. sessile 21 18 15 47 59 95
S. molesta 54 227 200 374 28 39
F. (fusca group) 2 5 0 6 96 533
F. schaufussi 1 1 0 1 5 4
C. ferrugineus 1 0 0 6 10 0
M1 minimum 13 27 13 1 0 246
P . pennsyl vani ca 1 24 7 0 3 6

 

30

Table 9. Direct observation of ant abundance and activity.

10/3/91
7/3/92

7/11/92
7/24/92

carrying an aphid

tending psylla

tending psylla

carrying' a jpsylla nymph and
a mite

10/3/91

9/12/92

feeding on apples and pears
on the ground

carrying psylla nymph
feeding on apples and pears
on the ground

C. cerasi

7/12/92
7/15/92

7/16/92
7/26/92

carrying psylla nymph (2 ants)
carrying psylla nymph (at least
6-7 psylla in one hour)
carrying psylla nymph (1 ant)
3 nests were found in Central
block.

many of this ant were killed
around L. neoniger nests near
Trevor Nichols.

carrying a staphylinid larva

 

31

Table 10. Comparison of ant captures on three different
ground baits, 1991 and 1992 (data transformed as Vx+0.5,

means followed by same letter not significantly
different, LSD, p=0.05).

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

|| 1991 ll
.
Species Baits 7/15 7/29 8/12 8/26 9/09 9/20 10/3 in

L.neoniger Catfood 3.768a 1.200a 0.846a 0.707a 0.707a 0.707a 0.707a
Jelly 0.795 b 0.794a 0.759a 0.846a 0.707a 0.846a 0.707a
Lard 0.759 b 0.759a 0.707a 0.707a 0.707a 0.707a 0.707a

P.imparis Catfood 3.2713 1.170a 0.707a 1.999a 8.156a 4.917a 9.309a E"
Jelly 0.846 b 0.759a 0.707a 1.214a 4.938 b 2.578 b 4.215 b y
Lard 0.759 b 0.707a 0.707a 0.707a 0.707 c 1.010 b 1.079 c 5

C.cerasi Catfood 0.707a 0.707a 0.707a 0.707a 0.707a 0.707a 0.707a F‘
Jelly 0.707a 0.707a 0.707a 0.707a 0.707a 0.707a 0.707a
Lard 0.707a 0.707a 0.707a 0.707a 0.707a 0.707a 0.707a

 

 

 

Species [Baits 6/28 7/12 7/26 8/9 8/23 9/20 9/27

L.neoniger Catfood 3.660a 4.470a 4.6803 0.823a 0.707a 0.707a 0.707a
Jelly 1.067a 1.039 b 3.292a 0.707a 0.707a 0.707a 0.707a
Lard 1.154a 0.794 b 0.898a 0.707a 0.707a 0.707a 0.707a

P.imparis Catfood 2.985a 0.707a 0.707a 0.707a 1.030a 5.416a 2.549a
Jelly 0.848 b 0.707a 0.707a 0.707a 0.707a 1.339 b 1.701ab
Lard 0.846 b 0.707a 0.707a 0.707a 0.707a 1.066 b 1.047 b

C.cerasi Catfood 0.707a 1.012a 5.026a 0.707a 0.707a 0.707a 0.707a
Jelly 0.707a 0.910a 1.596ab 0.707a 0.707a 0.707a 0.707a
Lard 0.707a 0.848a 0.884 b 0.707a 0.707a 0.707a 0.707a

 

 

 

 

 

 

 

 

 

 

 

32

Table 11. Comparison of ant captures in ground bait traps
in West,
(data transformed as Vx+0.5, means followed by same
letter not significantly different, LSD, p=0.05).

Central,

and East block in 1991 and 1992

 

l

 

 

 

 

 

 

 

 

 

   

 

 

 

 

 

 

 

 

1991
1
Species Treat- 7/15 7/29 8/12 8/26 9/9
ments
=
L.neoniger I 3 829ab 1.246a 0 875a 0.737a 0.846ab 0.707a 0.707a
II 6.574a 2.086a 0 707a 0.724a 1.725a 0.707a 0.707a
III 1.039 b 0.862a 0 707a 0.861a 0.759 b 0.707a 0.707a
P.imparis I 3.286a 1.18 a 0 707a 2.139a 9.536a 5.552a 10.089a
II 1.851a 0.76 a 0.707a 1.055a 5.728ab 5.884a 3.732b
III 0.759a 0.707a 1 73 a 1.481a 3.914 b 1.582 b 2.526b
C.cerasi I 0.707a 0.707a 0 707a 1.099a 0.707a 0.707a 0.707a
0. 0. 0 1. 0.707a 0.707a 0.707a
0. 0. 0 1. 0. 0.

      

 

 

 

 

 

 

 

 

 

 

 

Species Treat- 6/28 7/12 7/26 8/9

ments

L.neoniger II 1.216a 7.601a 5.121a 1.069a 0.707a 0.707a 0.707a
I 3.798a 4.53 ab 6.842a 0.824a 0.707a 0.707a 0.707a
III 0.960a 2.249 b 2.249a 1.118a 0.759a 0.707a 0.707a

P.imparis II 4.384a 1.326a 1.860a 0.707a 0.707a 1.666a 4.826a
I 3.023ab 0.707a 0.707a 0.707a 1.030a 1.720a 3.033ab
III 0.759 b 0.759a 0.707a 0.707a 0.707a 0.963 b 1.345ab

C.cerasi II 0.707a 0.707a 0.707 b 0.707a 0.707a 0.707a 0.707a
I 0.707a 0.863a 2.097a 0.707a 0.707a 0.707a 0.707a
III 0.707a 0.707a 0.707 b 0.707a 0.707a 0.707a 0.707a

 

 

 

 

 

33

Table 12. Comparison of ant captures in tree bait traps
in West, Central, and East block in 1991 and 1992
(data transformed as ¢x+0.5, means followed by same
letter not significantly different, LSD, p=0.05).

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1991
if
Species Treat- 7/16 7/30 8/13 8/27 9/10 9/21 10/4
ments
‘ ——
L.neoniger I 0.759a 0.707a 0.759a 0.707a 0.707a 0.707a 0.707a
II 0.707a 0.707a 0.707a 0.707a 0.707a 0.707a 0.707a
III 0.976a 0.707a 0.707a 0.707a 0.707a 0.707a 0.707a
P.imparis I 1.422a 0.707a 0.707a 0.976a 3.959a 1.508a 3.412a
II 1.121a 0.707a 0.707a 0.707a 1.44 a 0.759a 1.385 b
III 0.912a 0.707a 0.707a 0.707a 2.020s 0.979a 0.996 b
C.cerasi I 0.707a 0.707a 0.707a 0.707a 0.707a 0.707a 0.707a
II 0.707a 0.707a 0.707a 0.707a 0.707a 0.707a 0.707a
III 0.707a 0.707a 0.707a 0.707a 0.707a 0.707a 0.707a

 

 

 

 

 

 

 

 

 

 

 

 

 

Species Treat- 6/27 7/11 7/25 8/8 8/22 9/5 9/19

ments

L.neoniger II 1.653a 3.440a 4.004a 0.707a 0.707a 0.707a 0.707a
I 3.083a 2.754a 3.098ab 0.824a 0.707a 0.795a 0.759a
III 0.945a 0.875a 1.121 b 1.983a 0.759a 0.759a 0.707a

P.imparis II 1.375a 0.707a 0.707a 0.707a 0.707a 0.707a 4.084a
I 0.824a 0.707a 0.707a 0.707a 0.707a 0.707a 1.995a
III 0.707a 0.707a 0.707a 0.707a 0.707a 0.707a 1.413a

C.cerasi II 0.707a 0 707a 0.707a 0 707a 0.707a 0.707a 0.707a
I 0.707a 0.707a 0.795a 0.707a 0.707a 0.707a 0.707a
III 0.707a 1.030a 0.707a 0.707a 0.707a 0.707a 0.707a

 

 

 

 

 

34

Table 13. Comparison of ant captures in.pitfall traps in West,
Central, and East block in 1991 and 1992 (data
transformed as t/x+0.5, means followed by same letter not
significantly different, LSD, p=0.05).

 

 

 

 

 

1991 J]
T
Species Treat- 7/17 7/31 8/14 8/28 9/11 9/18 10/2
ments
L.neoniger I 5.753a 2 991a 1.018a 3.102ab 2.397ab 1.363a 1.004 b
II 7.926a 3 547a 1.269a 4.522a 3.473a 1.566a 1.436a
III 2.775 b 1 977a 1.799a 2.266 b 1.797 b 1.546a 0.811 b It
P.imparis I 1.422a 0.707a 0.707a 1.725a 7.989a 7.915a 5.134a
II 1.121a 0.707a 0.707a 1.187a 4.491 b 5.937a 3.444 b
III 0.912a 0 707a 0.707a 0.882a 4.12 b 2.945 b 1.960 c
L!
C.cerasi I 0.707a 0 759a 0.707a 0.707a 0.811a 0.707a 0.707a
II 0.759a 0 8713 0.910a 0.882a 0.759a 0.707a 0.707a
III 0.862a 0 707a 0.811a 0 707a 0.707a 0.707a 0.707a

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Species
L.neoniger II 3.740a 5.192a 3.191a 2.386ab 1.950a 1.869a 1.651a
I 4.689a 5.706a 3.446a 3.059a 1.619a 2.627a 2.395a
III 3.515a 3.253 b 1.913 b 1.605 b 1.848a 1.492a 1.377a
P.imparis II 1.422a 1.492a 1.272a 0.811a 0.95 a 0.846a 3.561a
I 1.031a 0.810 b 0.759 b 0.707a 0.707a 0.759a 2.395a
III 1.356a 0.707 b 0.795 b 0.707a 0.707a 0.94 a 1.377a
C.cerasi II 0.707a 0.707a 0.707a 0.707a 0.707a 0.707a 0.759a
I 0.898a 0.707a 0.759a 0.707a 0.846a 0.707a 0.707a
III 0.707a 0.759a 0.759a 0.759a 0.707a 0.707a 0.707a
3mm _

 

 

 

35

The population of L. neoniger tended to decrease over
time (Figures 6, 8, and 10-15). Traniello & Levings (1986)
showed that this ant species is active in early summer and
expands its foraging area until mid summer. Data showed a
similar activity cycle.

L. neoniger was attracted to the protein bait in higher
numbers even though it is not significantly different from
the two other baits except in mid July (p=0.05) (Table 13).
Edwards (1951) noticed that L. niger ‘may' have seasonal
preference for protein or carbohydrate, but no strong
preference was exhibited by Lu neoniger (Table 13). It was
also attracted to sugar baits in higher numbers than lard
baits, but the capture was not significantly different
(p=0.05) (Table 13) . Although it was captured in higher
numbers in protein baits and sugar baits, L. neoniger
occasionally came to the lard baits.

Direct observation showed that this ant may also consume
small arthropods such as mites and aphids, as a protein
source, in addition to the psylla nymphs (Table 9) . Because of
this predation of several insects, this species has potential
as a good biological control agent. However, the ant was found
tending psylla and may protect them from attacks by predators.
Other congener species frequently form mutualistic
associations with honeydew producing homopterans (Way 1963).

Application of insecticides seems to affect L. neoniger

populations on several dates as indicated by pitfall trap

 

36

 

"ll.” 01 0018 L. umber

 

 

 

 

 

 

o T T I I 1
7117/81 7181/81 01 14181 0180/81 8/11/81 8110/81 1812/81

1

 

 

Number of ants P. hurls

 

10
.c-i
a-i

7-

 

 

 

 

o. f , p

1 1
7117/81 7101/81 0114/81 0/80/81 8111/81 8110/81 1818/81

*Wbst +ceiitral +Eut

 

 

 

Figure 6. Number (transformed \/X+O.5) of L. neoniger and P.
imparis captured in pitfall traps across West,
Central, and East blocks in 1991.

37

 

‘0 Number 01 ante M. enema

 

 

 

 

 

 

l I 1 1 1
7117/81 7/81/81 0114/81 0180/81 8111/81 8118181 018181

 

 

 

 

Number of arm 0. met

 

1O
“-4
a-«
7-1
0..
5..
4...
a—i
2..
1%
Or

I 1 T l r I
7117/81 7101/81 0114/81 0180/81 8111/81 8110/81 1012/81

 

 

“-1708! -I-centrel +5011

 

 

 

Figure 7. Number (transformed Jx+0.5) of M1 emeryana and C.
cerasi captured in pitfall traps across West,
Central, and East blocks in 1991.

 

38

 

Nil-her e! ante 1. use“
10

 

e-(

.4

 

 

 

 

I I 1 r

else/ea 7mm nuns Inlet arms Ole/ea m
Coulee dues

 

 

Neither of ante P. taper-Ia

 

18
.4
.-
7-i
0'1
5-
4-

   
  

3'
8‘

 

 

 

1 T 1 I 1
0180188 710188 7184188 017188 0181/88 814/88 8110/88
“who Gabe

*Weet +ceiitral +5“!

 

 

 

Figure 8. Number (transformed ¢x+0.5) of L. neoniger and P.
imparis captured in pitfall traps across West,

Central, and East blocks in 1991.

 

39

 

Number 0! elite u emeryeee

 

10

.J

  

8'] I
1 :/4\‘_’/” 'E1

0 I I 1 1
012010: 1110102 71:00! .11/0! 0121/02 sum m1
Milne detee

 

 

 

 

 

 

 

 

 

Number 01 elite C.cerasi

 

10
H
..
1-1
..
0-1
4.
3.
21
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1

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40

 

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46

samples (Table 13). L..neoniger numbers in the East blok could
be attributed to low pear psylla prey numbers. The impact of
pesticides is supported by informal observations that L.
neoniger nests were found throughout the West and Central
blocks, but were found only in a portion in the East block.
Avermectin is used in the Southeastern US for control of red
imported fire ant (Solenopsis invicta Buren) (Greenblatt et.
al. 1986) and.may be impacting L..neoniger populations in this
trial. However, a determination of this impact is outside the
scope of this study.

Interspecific competition may play an important rule in
the ant distribution” More Ch cerasi and .Formica (fusca
group), were captured in the east block. Cole (1983) noticed
that when a colony of either one of two dominant species, C.
ashmeadi'and Xenomyrmex floridanus is established first, it

precludes the invasion by the subordinate species.

Prenolepis imparis.

P. imparis are dominant in woodland and make their nests
in the ground in shady positions (Talbot 1943, Chreigton 1950,
Fellers 1989). It peaked in numbers in early fall. This
species began with moderately high in early summer and then
decreased in the middle of summer (Figures 6, 8, and 10-15).
The ants that were captured at the beginning of the study
might have been a part of declining population toward mid

summer. The data showed that this species was greatly affected

47

by temperature as similar to reports by Talbot (1943) and
Fellers (1989). The workers of this species were observed
above ground at 3.19C. As the temperature rises, its activity
increases rapidly until the temperature reaches between 7.2 to
18.3°C (Talbot 1943). Its activity begins to decline at higher
temperatures (Talbot 1943). Lynch et al. (1980) reported that
this species had two seasonal peaks occurring around May and
November. Data showed that the population begin to increase in
late August or early September (Figure 6, 8). The tree bait
trap data showed a population decline on September 20, 1991
(Figure 12). This may relate to increased food availability in
the ground and decreased attractiveness of the bait. At this
time, large numbers of pear fruit were on the ground. They may
use this source of food to reduce its foraging area.

P. imparis was captured in significantly higher numbers
on protein baits compared to other baits (p=0.05) (Table 10).
Lynch et al. (1980) noticed that this species were captured in
higher number with protein-fat baits. Small arthropods such as
aphids and leafhoppers, may be a part of its diet, especially
after the first frost at early winter (Talbot 1943). This
species was seen carrying psylla nymphs; it may eat the
psylla.

Fruit may be almost exclusively the source of food for P.
imparis, although it may have some other foods (Talbot 1943).
The workers were observed consuming decaying apple and pear

fruit on the ground (Table 9).

48

P. imparis populations were significantly lower in the
pesticide treatments only in the 9/11 and 9/18 pitfall samples
in 1991, and.were not impacted by Mitac (treatment II on 9/18)
(Table 13). By contrast, there was no impact by pesticide
treatments in 1992, with P. imparis numbers actually
significantly higher in treatment II during 7/10, 7/24, and
8/07 pitfall samples (Tables 13). This lower number of ants in
the East block (treatment III) could also attributed to low

pear psylla populations.
The lower population number of P. imparis in the second
year may relate to decreased food.availability. It seemed that
at this time less fruit were available. Higher precipitation

in 1992 may have washed honeydew from the trees.

Crematogaster cerasi.

C. cerasi showed relatively low population numbers and no
cyclical pattern either in 1991 or 1992. Interestingly, in the
first year of the study, the workers were mostly captured in
the East block, in the second year the numbers were higher in
the Central block (Table 8). They were not found in tree baits
in the first year even though they may forage in the tree.
They may be more attracted to their natural food.

A preference for protein and sugar baits was exhibited
only once in 1992 (p=0.05) (Table 12). However, they more
frequently visited the protein bait.

Among the other ants found in this study, C. cerasi may

49

be the most promising ant for biological control of pear
psylla, although it may tend homopterans (Thompson 1990).
Timti (1991) reported the success of Crematogaster species in
controlling a leaf miner, Coelaenomenodera minuta Uhlmann, in
oil palm trees. The species C. punctulata Emery was believed
as a key predator of a range caterpillar, Hemileuca oliviae
Cockerell (Shaw et al. 1987). Direct observation showed that,
in one hour, at least 6-7 psylla nymphs were carried away by
workers of this species (Table 9). A nest dissection showed
the nymphs in the ant nest were partly'destroyed, probably due
to its chewing activity. Nests were observed in contact with
the soil and also above ground in trees.

Despite these advantages, C. cerasi had low population
numbers. In the first year, the higher numbers were captured
in the pheromone disruption block. A nest was found in this
block in the dead part of a pear tree. In the second year,
more ants were recorded.in Central block (Table 8. Three nests
were found in a decaying log and dead parts of pear trees. The
availability of dead wood or logs for nesting may limit the
distribution of this species throughout the orchard. Because
of its low'population.numbers, the effect of the pesticides on

C. cerasi was difficult to measure.

Other Ants.
Even though it was not observed preying on pear psylla,

myrmica emeryana was the third most common species. This ant

50

species was captured in all kinds of traps (Table 6).
Interestingly, in the first year of study, none of this
species was caught in the tree bait traps. In the second year,
some workers were captured in those traps (Table 7). This may
relate to decreased food availability on the ground. One
individual of this species was captured in.a pitfall trap with
a staphylinid larvae in its mouth.

Ml emeryana may be active from late spring through early
fall (Fellers 1989). This was also supported by the data
(Figure 7 and 9). Traniello (1987) noticed that M: americana
is temperature-dependent. This species was active throughout
1991 and 1992. In 1992, larger numbers of this species were
caught when P. imparis numbers were lower (Table 7).

Traniello (1983) reported that its relative, M. americana
make nests in the ground.uear their co-occurring species nest,
L. neoniger. They may share the same nest site preference,
diurnal foraging time, seasonal foraging activity, and prey
type and size with L. neoniger (Traniello 1983). M3 emeryana
may unsuccessfully compete its neighbor. Dead bodies of this
species were found.around.L..neoniger nest near Trevor Nichols
Research Station.

A very low number of Tapinoma sessile was recorded in the
soil samples, and none were found in tree traps in the first
year. Creighton (1950) noticed that it appeared to prefer

honeydew‘when it can.get them. In the second year, many of the

51
workers were captured in tree traps. Like M3 emeryana, this
might relate to food availability.

Fellers (1989) recorded that T. sessile may not have
distinct seasonal patterns, and the workers may be active
through the season (Harada 1990). The data from this study
showed a similar pattern. Diurnal foraging activity begins in
March (Fellers 1989, Harada 1990). This species is restless
and move the nests about every 25 days (Smallwood 1982). Its
nests may be under stones, in soil, boards, dead leaves, wasp
and bird nests and houses (Smith 1928).

Although they may be good forager and nurses, and prey
on many important pests (Harada 1990), T. sessile may not be
good as a biological control agent. They are aphidicolous and
cocciducolous species (Smith 1928, Bristow 1984). The more
important thing that have to be considered is that they may
transmit plant diseases (Harada 1990).

Solenopsis molesta and Monomorium minimum exhibited a
similar preference in food choice. These two species visited
more lard than the other baits. These two ants were not found
in the tree baits. They were not observed carrying pear
psylla. Traniello (1987) saw that M. minimum is more active in
the evening. In this study, it seemed that both ants were more
active in the evening.

Lipid preference of S. molesta was also mentioned by
Hayes (1920). He observed that this species tended aphids,

instead of feeding on small arthropods. The tree bait trap

52
data and.direct observation showed that this species, like the
other two ants, M1 minimum and Ponera pennsylvanica, did not
forage on the tree, therefore; they probably do not affect
pear psylla.

Formica (fusca group) is one of the largest ant in the
orchard. Non-significant higher numbers of ants were captured
in the sugar bait. More Formica (fusca group) were captured.in
1992 than in 1991.

Observation of Fbrmica (fusca group) suggests that this
species may tend psylla. Dreisig (1988) reported that Formica
(fusca group) attended field colonies of Aphis acetosae L. The
ants quickly suck up honeydew and retreat if they are
approached by other ants. This species is also an opportunist
with little competitive ability (Brian et al. 1966).

Fbrmica schaufussi was captured fewer times than other
ants in this study. The species may live sympatrically with
other ants such as L. neoniger, M2 americana, MK minimum and
Tetramorium caespitum CTraniello 1983). Its foraging activity
may also temporally overlap with those ants (Traniello 1987).
A preference to the baits was not demonstrated, but Traniello
(1987) noticed that this species may carry either small or
relatively large prey.

The biggest ant in the orchard, camponotus ferrugineous,
was only captured a few times in the pitfall with extremely
low numbers (Table 7 and 8). This species is nocturnal at

least in July (Lynch et al. 1980, Fellers 1989).

53
Ponera pennsylvanica may be the only ant that spends its
entire life in the soil. It may make a nest in rotten wood
(Creighton 1950).It was never captured in other traps except
in soil samples with extremely low numbers. The number was

little bit larger in the second year.

CONCLUS IONS

54

CONCLUSIONS

Eleven species of ants were captured in the orchard. L.
.neoniger and P. imparis were the most abundant ants, but they
may not as important as C. cerasi as a candidate for
biological control of pear psylla. Ch cerasi showed, at least,
its ability to seek for psylla nymphs. Despite of that
advantage, C. cerasi showed a small population number
throughout the orchard. A further study is needed to know the
effect of the other ants to C. cerasi.

One species, P. pennsylvanicus, was only found in the
soil samples. This suggest that this species, probably, spends
its life in the soil or they may not as active as the others.

.Almost all of the ants showed.a preference to the protein
and the sugar bait, except S. molesta and ML minimum. These
two ants may prefer lard, even though they also need protein
and sugar. The ants may have other food from other sources
such as decaying fruit and small arthropods.

Two species, L. neoniger and F. fusca group, showed their
attendance to psylla or aphids colony. They may have honeydew,
while they protect the homopterans.

It appeared that ants were greatly affected by the
temperature. P. imparis may respond positively to the

temperature decline, while others may react negatively. The

55
1992 precipitation may benefit to the other ants. Pesticide
applications significantly influenced ant populations in the

orchard.

References

56

References

Adenuga, A.O. & K. Adeboyeku. 1987. Notes on distribution of
ant-homoptera interaction on selected crops plants.
Insect Sci. Applic. 8(2): 239-243.

Brian, M.V. 1956. Segregation of species of genus.MYrmica. J.
Anim. Ecol. 21: 12-24.

Brian, M.V., J. Hibble. &.A.F. Kelly. 1966. The dispersion of

ant species in a southern English heath. J. Anim. Ecol.
35: 281-290

Bristow, C. 1984. Differential benefits fromxant attendance to

two species of Homoptera on New York ironweed. Journal of
Animal Ecology 53: 715-726.

Brunner, J.F. & A.J. Howitt. 1981. Pear psylla. Tree fruit
insects. North Centr. Reg. Ext. Publ. No. 63.

Burts, E.C. 1983. Effectiveness of a soft-pesticide program on
pear pests. J. Econ. Entomol. 76: 936-941.

Burts, E.C. 1988. Damage threshold for pear psylla nymphs
(Homoptera: Psyllidae) . J. Econ. Entomol. 81(2): 599-601.

Butt, B.AJ, L.C. Stuart & R.L. Bell. 1989. Feeding, longevity,
and development of pear psylla (Homoptera: Psyllidae)

nymphs on resistant and susceptible pear genotypes. J.
Econ. Entomol. 82(2): 458-461.

Cappaert, D.L. 1989. The role of ants in biological control of
agricultural pests. Submitted.to.Agriculture, Ecosystems
and Environment (unpublished).

Creighton, W.S. 1050. The ants of North America. Printed for

the museum. Spaulding-Moss Company. Cambridge. Mass.
585 pp.

Dreisig, H. 1988. Foraging rate of ants collecting honeydew'or
extrafloral nectar, and some possible constrains. Eco.
Ento. 13: 143-154.

Eichler, Wd. 1990. Health aspects and control of Monomorium
pharaoensis, in Applied Myrmecology, edited by R.K.

57

Vander Meer, K. Jaffe, and A. Cedeno. Westview Press.
Boulder, CO. pp. 671-675.

Fellers, J.H. 1989. Daily and seasonal activity in woodland
ants. Oecologia 78: 69-76.

Fye, R.E. 1985. Corrugated fiberboard traps for predators
overwintering in pear orchards. J. Econ. Entomol. 78:
1511—1514.

Green, G.W. & C.R. Sullivan. 1950. Ants attacking larvae of
the forest tent caterpillar, Malostoma disstria an.
(Lepidoptera: Lasiocampidae). Can. Ent. 82: 194-195.

Greenblatt, J.A., J.A. Norton, R.A. Dybas & D.P. Harlan. 1986.
Control of the red imported fire ant with abamectin
(Affirm), a novel insecticide, in individual mound
trials.

Godfrey, K.E., W.H. Whitcomb & J.L. Stimac. 1989. Arthropod
predators of velvetbean caterpillar, Anticarsa gemmatalis
Hubner (Lepidoptera: Noctuidae) eggs and larvae. Environ.
Entomol. 18(1): 118-123.

Goonewardene, H.F., G. Pliego, G.P. McCabe, P.H. Howard.& P.J.
Oliver. 1989. Control of Arthropods on apple, Malus x
domestica (Borkh), Selections for scab (Ascomycetes:
Mycosphaerellacea) and apple maggot (Diptera:
Tephritidae) Resistance in an orchard in Indiana. J.
Econ. Entomol. 82(5): 1426-1436.

Hagley, E.A.C. & C.M. Simpson. 1983. Effect of insecticides on
predators of the pear psylla, Psylla pyricola (Hemiptera:
psyllidae) in Ontario. Can. Ent. 115: 1409-1414.

Harada, A.Y. 1990. Ant pests of the Tapinomini tribe, edited
by R.K. Vander Meer, K. Jaffe, and A. Cedeno. Westview
Press. Boulder, CO. pp. 298-315.

Harries, P.H. & E.C. Burts. 1965. Insecticide resistance in
the pear psylla. J. Econ. Entomol. 58(1): 172-173.

Hayes, W.P. 1920. Solenopsis molesta (Hym.): A biological
study. Kans. Sta. Agric. Coll. Tech. Bull. 7: 1-55.

Holldobler, B. & E.C. Wilson. 1990. The ants. The Belknap
Press of Harvard University Press, Cambridge,
Massachusetts. 732-pp.

Horton, D.R. & J.L. Krysan. 1990. Probing and oviposition-
related activity of summerform pear psylla (Homoptera:

58

Psyllidae) on host and nonhost substrates. Environ.
Entomol. 19(5): 1463-1468.

Knight, R.L. & M. K. Rust. 1990. Repellency and efficacy of
insecticides against foraging workers in laboratory

colonies of Argentine ants (Hymenoptera: Formicidae). J.
Econ. Entomol. 83(4): 1402-1408.

Krysan, J.L. 1990. Fenoxycarb and diapause: A.possible method
of control for pear psylla (Homoptera: Psyllidae). J.
Econ. Entomol. 83(2): 293-299.

Lofgren, C.S., W.A. Banks, & B.M. Glancey. 1975. Biology and
control of imported fire ants. Ann. Rev. Ent. 20: 1-30.

Lynch, J.F., E.C. Balinsky' & S.G. ‘Vail. 1980. Foraging
patterns in three sympatric forest ant species,
Prenolepis imparis, Paratrechina melanderi and
Aphaenogaster rudis (Hymenoptera: Formicidae) . Eco. Ento.
5: 353-371.

Madsen, H.F. & P.H. Westigard. 1963. Control of pear psylla
with oils and oil pyrethrins. Calif. Agric.

Madsen, H.F. & T.T.Y. Wong. 1964. Effects of predator on
control of pear psylla. Calif. Agric. 18: 2-3.

Nechols, JLR. & THF. Seibert. 1985. Biological control of
the sphaerical mealybug, Nipaecoccus vaspator
(Homoptera: Pseudococcidae) : Assessment by ant exclusion.
Environ. Entomol. 14: 45-47.

Philogene, B.J.R. & J.F. Chang. 1978. New record of parasitic
chalcicoids of pear psylla (Homoptera: Psyllidae) in
Ontario, with observations on the current word status of
its parasitoids and predators. Proc. Ent. Soc. Ont. 109:
53-60.

Poulson, G.S. & R.D. Akre. 1991a. Predatory ants can help
control pear psylla. Good Fruit Grower. p. 12-13.

Poulson, G.S. & R.D. Akre. 1991b. Role of predaceous ants in
pear psylla (Homoptera: Psyllidae) management: estimating
colony size and foraging range of Formica neoclara
(Hymenoptera: Formicidae) through a mark-recapture
technique. J. Econ. Entomol. 84(5): 1437-1440.

Quamme, H.A. 1984. Observations of pear psylla resistance
among several pear cultivars and species. Fru. Var.
Journal 2: 34- 36.

59

Reidl, H., P.H. Westigard, R.S. Bethell & J.E. DeTar. 1981.
Problems with chemical control of pear psylla. Calif.
Agric. 7-9.

Risch, S.J. & C.R. Carroll. 1982. The ecological role of ants
in two Mexican agroecosystems. Oecologia 55: 114-119.

Shaw, P.B., J.C. Owens, E.W. Huddleston & D.B. Richman. 1987.
Role of arthropod predators in mortality of early instars
of the range caterpillar, Hemileuca oliviae (Lepidoptera:
Saturniidae). Environ. Entomol. 16: 814-820.

Slingerland, M.V. 1896. The pear psylla. Cornell University
Agr. Expt. Sta. Bull. 108: 69-81.

Smallwood, J. 1982. Nests relocation in ants. Insectes Socioux
29: 138-147.

Smith, W.P. 1928. Solenopsis molesta Say (Hym.): Kansas State
Agricultural College. Technical Bulletin 7: 1-55.

Sokal, R.R. & F.J. Rohlf. 1981. Biometry. W.H. Freeman and
Company, New York. 859 pp.

Sterling, W.L., D.A. Dean, D.A. Fillman & D. Jones. 1984.
Naturally-occurring biological control of the boll weevil
(Col: Curculionidae). Entomophaga 29(1): 1-9.

Sudd, J.H. & N.R. Franks. 1987. The behavioral ecology of
ants. Chapman and Hall. New York.

Tabashnik, B.E., B.A. Croft & J.A. Rosenheim (1990). Spatial
scale of fenvalerate resistance in pear psylla
(Homoptera: Psyllidae) and its relationship to treatment
history. J. Econ. Entomol. 83(4): 1177-1183.

Talbot, Mary. 1943. Response of the ant Prenolepis imparis.Say
to temperature and humidity changes. Ecology 24(3): 345-
352.

Tedders, W.L., C.C. Reilly, E.W. Wood, R.K. Morrison & C.S.
Lofgren. 1990. Behavior of Solenopsis invicta
(Hymenoptera: Formicidae) in pecan orchards. Environ.
Entomol. 19(1): 44- 53.

Thompson, C.R. 1990. Ants that have pest status in the United
States, in Applied Myrmecology, edited by RHK. vander
Meer, K. Jaffe, and A. Cedeno. Westview Press. Boulder,
co. pp. 51-74.

6O

Tilman, D. 1978. Cherries, ants and tent-caterpillars: timing
of nectar production in relation to susceptibility of
caterpillars to ant predation. Ecology 59(4): 686-692.

Timti, I.N. 1991. Control of Cbelaenomenodera minuta Uhlmann
with.species Crematogasteru Trop. Pest. Mngt. 37(4): 463-
467.

Traniello, J.F.A. 1983. Social organization. and foraging
success in Lasius neoniger (Hymenoptera: Formicidae):
behavioeal and ecological aspects of recruitment
communication. Oecologia 59: 94-100.

Traniello, J.F.AJ 1987. Comparative foraging ecology of North
temperate ants: the role of worker size and cooperative
foraging in prey selection. Insectes Sociaux 34(2): 118-
130.

Traniello, J.F.A & S.C. Levings. 1986. Intra- and intercolony
patterns of nest dispersion in the ant Lasius neoniger:
correlations with territoriality and foraging ecology.
Oecologia 69: 413-419.

Ullman, D.E. & D.L. McLean. 1988. Feeding behavior of the
winter-form pear psylla, Psylla pyricola (Homoptera:
Psyllidae) on reproductive and transitory host plants.
Environ. Entomol. 17(4): 675-678.

van den Bosch, R & P.S. Bessinger. 1982. An introduction to
biological control. Plenum Press. New York. 247 pp.

Warner, G. 1991. Insect grow regulator are possible pear
psylla control. Good Fruit Grower. March. 6-8.

Way, M.J. 1963. Mutualism between ants and honeydew-producing
Homoptera. Ann. Rev. Entomol. (8): 307-344.

Westigard, P.H., L.G. Gentner & D.W. Berry. 1968. Present
status of biological control of the pear psylla in
Southern Oregon. J. Econ. Entomol. 61(3): 740-743.

Westigard, P.H. 1974. Control of the pear psylla with insect
growth regulators and preliminary effects on some non-
target species. Environ. Entomol. 3: 256-258.

Westigard, P.H., P.B. Lombard.& D.W. Berry (1979). Integrated
pest management of insects and mites attacking pears in
southern Oregon, Oreg. Agric. Exp. Stn. Bull. 634.

Westigard, P.H., P.B. Lombard, R.B..Allen.&:J.G. Strang. 1980.
Pear psylla: Population suppression through host plant

61

modification using daminozide. Environ. Entomol. 9: 275-
277.

Westigard, P.H. & H.R. Moffitt. 1984. Natural control of the
pear psylla (Homoptera: Psyllidae): import of mating
disruption with the sex pheromone for control of the

codling moth (Lepidoptera: Tortricidae). J. Econ.
Entomol. 77: 1520-1523.

Westigard, P.H., L.J. Gutt & W.J. Liss. 1986. Selective

control program for the pear pest complex in Southern
Oregon. J. Econ. Entomol. 79: 250-257.

Wheeler, W.M. 1914. The ants of the Baltic amber. Schr. Phys.
Okon. Ges. Konigsberg 55:1-142.

Appendices

62
APPENDIX 1

Record of Deposition of Voucher Specimens*

The specimens listed on the following sheet(s) have been deposited in
the named museum(s) as samples of those species or other taxa which were
used in this research. Voucher recognition labels bearing the Vbucher
No. have been attached or included in fluid-preserved specimens.

Voucher No.: 1993-02

Title of thesis or dissertation (or other research projects):
A survey of ants as candidates for potential biological control of
pear psylla (Cacopsylla pyricola (Foerster)) in Michigan;

 

Museum(s) where deposited and abbreviations for table on following sheets:
Entomology Museum, Michigan State-University (MSU)

Other museums:

' Investigator's Name (a) (typed)

---. who

 

 

 

Date 5124Q993

*Reference: Yoshimoto, C. M. 1978. Voucher Specimens for Entomology in
North America. Bull. Entomol. Soc. Amer. 24:141-42.

Deposit as follows:

Original: Include as Appendix 1 in ribbon copy of thesis or
dissertation. .

Copies: Included as Appendix 1 in copies of thesis or dissertation.
Museum(s) files.
Research project files.

This form is available from and the Voucher No. is assigned by the Curator,
Michigan State University Entomology mseum.

 

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63
APPENDIX 1.1
Voucher Specimen Data

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