recognizing the good bugs in cotton - texas a&m...

E-3577-05

Field Guide to Predators, Parasitesand Pathogens Attacking Insectand Mite Pests of Cotton

by Allen Knutson and John Ruberson

Recognizing theGood Bugs inCotton

Recognizing theGood Bugs inCotton

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Field Guide to Predators, Parasitesand Pathogens Attacking Insect

and Mite Pests of Cottonby Allen Knutson and John Ruberson

This publication was made possible in partthrough financial support provided by CottonIncorporated.

Cover photograph by W. Sterling of an immature(nymph) spined soldier bug, a predator of bollwormsand other caterpillars in cotton.

Authors: Allen Knutson, Professor and ExtensionEntomologist, Texas Cooperative Extension, TexasA&M Research and Extension Center-Dallas, 17360Coit Road, Dallas, TX 75252

John Ruberson, Assistant Professor, Department ofEntomology, University of Georgia, P.O. Box 748,Tifton, GA 31794.

Editor: Edna M. Smith, Communications Specialist,Texas Cooperative Extension.

Designer: David N. Lipe, Assistant Graphic Designerand Communications Specialist, Texas CooperativeExtension.

Texas Cooperative ExtensionEdward G. Smith, DirectorThe Texas A&M University SystemCollege Station, Texas

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CONTENTSIntroduction 3Acknowledgments 4How to Use This Book 6Biology of Natural Enemies 7Use of Natural Enemies 11Sampling for Natural Enemies 12Further Reading 15Table of cotton pests and their

natural enemies 16Pesticides and Natural Enemies 20Table of chemical classes and

cotton insecticides 23

PredatorsLynx Spiders 24Celer Crab Spider 26Jumping Spiders 28Green Lacewings 30Brown Lacewings 34Ground and Tiger Beetles 36Seven-spotted Lady Beetle or “C-7” 40Harmonia or Asian Lady Beetle 42Convergent Lady Beetle 44Pink Spotted Lady Beetle 46Collops Beetles 48Hooded Beetle 50Striped Earwig 52Rove Beetles 54Damsel Bugs 56Spined Soldier Bug 58Spined Assassin Bugs 62Leafhopper Assassin Bug 64Big-eyed Bugs 66Hover or Syrphid Fly 68

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Long-legged Fly 70Insidious Flower Bug 72Minute Pirate Bug 72Scymnus Lady Beetle 74Stethorus Lady Beetle 76Fire Ants 78Six-Spotted Thrips 80Predatory Mites 82

ParasitesArchytas marmoratus 84Tachinid Flies 86Macrocentrus grandii 88Microplitis croceipes 90Cardiochiles nigriceps 92Chelonus insularis 94Bracon mellitor 96Hyposoter Parasite 98Cotesia marginiventris 100Catolaccus grandis 102Meteorus Parasite 104Lysiphlebus testaceipes 106Looper Parasite 108Stink Bug Egg Parasites 110Whitefly Parasites 112Mymarid Parasites 114Trichogramma Wasps 116

PathogensCotton Aphid Fungus 120NPV Disease 122Beauveria and other Fungi 124

Sources of entomological supplies back cover

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IntroductionThe role of natural enemies in cotton

pest management has often been obscuredby the widespread use of broad-spectruminsecticides. Nevertheless, cotton can sup-port a large complex of insects, spiders andmites that feed on cotton pests. For exam-ple, researchers in Arkansas recorded morethan 600 different species of beneficialarthropods in cotton. In California, ento-mologists estimated that some 300 to 350different species consistently breed in cot-ton fields. Of the many arthropod speciesoccurring in cotton, very few are pests; themajority are beneficial.

Recently, interest in beneficial arthro-pods has grown tremendously. This hasbeen encouraged by numerous changes inthe cotton production system — anincrease in beneficial numbers followingeradication of the boll weevil in someareas of the Cotton Belt, sale of Bt-trans-genic cotton, development of insecticidesthat are less toxic to beneficial insects, andgrowing public concern over pesticide use.The importance of beneficial species hasbecome increasingly apparent. Beneficialarthropods are critical for managing thebeet armyworm, they can dramaticallyreduce budworm and bollworm popula-tions, and they play key roles in managingmany other serious and potential pests.Given the number of insect species capableof feeding and reproducing on cotton, the

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fact that so few are actual pests is a pow-erful testimony to the importance of natur-al enemies.

It is therefore timely and important thata field guide be developed for identifyingkey natural enemies. We must point out,however, that this guide is not comprehen-sive; the number of beneficial species issimply too great (and the biology of manyis too poorly known) to permit the devel-opment of such a guide at the moment.Hopefully, such a task can be undertakensoon.

AcknowledgmentsThe authors are indebted to the many

colleagues who assisted in providing pub-lications and reviewing all or parts of themanuscript, including John Benedict,Steve Naranjo and James Hagler. Two pub-lications, in particular, formed the founda-tion of this guide. They are “Predaceousand Parasitic Arthropods in CaliforniaCotton Fields” authored by R. Van denbosch and K. Hagen in 1966 (published asBulletin 820 of the California AgriculturalExperiment Station), and “PredaceousInsects, Spiders and Mites in ArkansasCotton Fields” authored by W. H.Whitcomb and K. Bell (published asBulletin 690 of the Arkansas AgriculturalExperiment Station in 1964). These pio-neering bulletins were the first to help cot-ton growers, extension agents, and ento-

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mologists identify and appreciate the manypredators and parasites attacking cottonpests.

Appreciation is also extended to themany who generously offered slides for usein the field guide. Special recognition isextended to Winfield Sterling, Professor ofEntomology (retired) and Allen Dean,Research Associate at Texas A&MUniversity, for use of their slide set. Otherswho provided slides included W. Jones,USDA-ARS; D. Steinkraus, University ofArkansas; Steve Naranjo, USDA-ARS; M.Merchant, Texas A&M; B. Ree, Texas A&M;D. Waters, University of Georgia; M.Badgley, Biological Photography, MorenoValley, CA; M. Scott, Illinois NaturalHistory Survey; J. Morales-Ramos, USDA-ARS; H. Gross, Jr. USDA-ARS; M. Rose,Texas A&M; Jack Kelly Clark, theUniversity of California Statewide IPMProject; Ed Thomas; Andrea Southworth,Univ. Georgia; and the University ofFlorida Department of Entomology. Wealso thank Russ Ottens for the figure ofstinkbug mouthparts and W. A. Frank andJ. E. Slosser for use of the figures fromtheir publication “An Illustrated Guide tothe Predaceous Insects of the NorthernTexas Rolling Plains,” Texas AgriculturalExperiment Station Bulletin MP-1718.

The authors also thank Pat O’Leary,Cotton Incorporated, for her support andassistance.

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How to Use This BookWe have attempted to design this hand-

book in such a manner that the necessaryinformation can be quickly and easilyaccessed by the user. For each naturalenemy, on the left-hand page we presentthe name of the natural enemy, the scien-tific name for the species or family, somegeneral information on its identification,the pests it attacks and its biology. In addi-tion, in the upper left corner is a silhouetteshowing the actual size of the adult natur-al enemy; or, if it is too small to show, amagnifying glass is displayed. On theright-hand page are color photographs andline drawings to help in identifying thenatural enemy, as well as a color-codedband signifying whether the natural enemyis a predator, a parasite, or a pathogen.The book is arranged so that the predatorsare presented first, the parasites (all fliesand wasps) second, and the pathogenslast. Each of these sections is color codedwith a strip on the figure page. Within thepredator and parasite sections, the insectsand spiders are arranged in order of size— from largest to smallest. The relativesizes can be seen by using the silhouetteand comparing them with the insect inhand. We need to emphasize that the sizerefers only to the adult stages. If imma-tures are found, the user will have to relyon the pictures for locating the organism.Finally, remember that this handbook isnot exhaustive. You will certainly see nat-ural enemies in cotton that are not includ-

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ed in this book. We have only focused onthose that we felt were most importantacross the Cotton Belt.

Biology of Natural EnemiesThe biologies of natural enemies in cot-

ton are extremely diverse and interesting,and are difficult to generalize. Nevertheless,there are some generalizations that can beuseful in considering natural enemies.Broadly speaking, beneficial organisms canbe categorized into three groups: predators,parasitoids (hereafter referred to as para-sites), and pathogens. Each of these groupsis briefly discussed below.

PREDATORS: Predators are those organisms that must

kill and consume more than one prey tocomplete their development, and are freeliving as immatures and as adults. Forexample, lady beetles may eat 400-500aphids during the course of their larvaldevelopment. Predators include numerousbeetles (lady beetles, ground beetles, rovebeetles, collops beetles, etc.), spiders, vari-ous true bugs (pirate bugs, damsel bugs,assassin bugs, some stink bugs, etc.),lacewings, and others. The action of preda-tors often goes unnoticed because manyspecies are small and hidden on the plant,and spend little time actually consumingprey. However, it is not unusual to seepredators actively feeding in the field if

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one looks carefully. Predators fall into twogroups, based on their feeding style: suck-ing and chewing predators. Sucking preda-tors typically have hollow mouthparts thatallow them to inject enzymes into theirprey and then suck the fluids and homoge-nized tissues out of the prey. Examples ofthis feeding type can be found in thepredaceous bugs and lacewings, amongothers. Chewing predators, such as mostlady beetles, use mandibles to chew andconsume their prey.

PARASITES: Parasites destroy a single host to com-

plete development, live in or on theirhosts during immature development, andare free-living only as adults. Many of theflies and wasps present in cotton are para-sites of other arthropods in cotton. Mostspecies of arthropods (pests and benefi-cials) have parasites that can attack themat some life stage. Parasites generally laytheir eggs in or on their hosts. The eggshatch, and the parasite larvae feed on thehost’s body fluids and/or tissues. Aftercompleting their larval development, theparasites pupate. They may pupate withinor on the host, or they may leave the hostand pupate elsewhere. The adult parasiteemerges from the pupa some time later.

Because many parasites feed internally,it is often not possible to look at an insectand determine if it is parasitized. Although

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a messy task, caterpillars can be pulledapart to determine if a parasite grub largeenough to see is inside. Also, insect eggsparasitized by tiny wasps turn black a fewdays after being parasitized. Of course thebest way is to collect the insect and keep italive to see if a parasite emerges. This isnot too difficult for insect eggs but often isnot practical for caterpillars which must befed and held for many days. Other evi-dence of parasite activity visible in thefield includes parasite cocoons, such asCotesia (p. 100) on cotton leaves, aphidmummies in aphid colonies (p. 107) andadult parasitic wasps or flies searching cot-ton plants for hosts.

Parasites may be solitary (one developsper host) or gregarious (more than onedevelops per host). They also tend to bespecific to the stages of the host that theyattack. For example, the tiny parasiticwasps of the genus Trichogramma attackonly eggs of their hosts. Also, some para-site species attack only one or a few relat-ed host species, while other parasitespecies attack many host species.

PATHOGENS:Pathogens are those organisms that

cause disease. In cotton, insects primarilyfall prey to pathogens that are fungi andviruses. Fungi typically attack the hostinsect directly by entering through theinsect’s cuticle. They reproduce within the

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host, ultimately killing it. They then growout of the host and produce spores thatspread to infect new hosts. Most virusesenter their hosts by being eaten. They thenpass into the host’s body and take over,converting the host into a virus factory. Inthe case of the nuclear polyhedrosis virus-es often found in cotton pests, the virussomehow induces the host to climb up theplant before it dies. The host then darkensand dies, dangling from a leaf or stem.The host’s body is filled with virus, andthe body wall becomes fragile, so that anydisturbance of the body causes the deadhost to burst or rupture. The virus-filledfluid then drips out of the dead host ontothe leaves and stems below where poten-tial hosts can feed and pick up the virus.

Naturally-occurring pathogens can behighly effective in reducing or eliminatingpest populations. This is particularly welldemonstrated by the cotton aphid fungus,Neozygites fresenii, which can decimatehigh aphid populations in 7-10 days insome areas of the Cotton Belt.

“BENEPESTS”: Some insect species can be both pest

and natural enemy. For example, lygusbugs, the cotton fleahopper and the blackfleahopper can inflict considerable damageon cotton plants, but can also be veryeffective predators of moth eggs, small lar-vae and in the case of lygus, whiteflies.Another example is the western flower

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thrips. It is a serious pest of seedling cot-ton throughout much of the Cotton Beltbut is also an important predator of spidermite eggs early in the season in California.At times these species may be more impor-tant as natural enemies than as pests,whereas at many other times the reverse istrue. We have not included these two-wayplayers in the handbook.

Use of Natural EnemiesThere are several approaches to using

natural enemies in crop production. Thefirst, and most useful, is to conserve thenatural enemies already present in the field.This may be done by minimizing use ofinsecticides, using selective insecticides orrates, by providing refuge habitats in oraround fields, or through use of foodsprays. The second method is augmenta-tion, or releasing natural enemies into afield. In most cases, these natural enemiesare purchased from a commercial supplier.Augmentation is an effective tool for man-aging pests in some crops, but additionalresearch on release rates, timing and eco-nomic return is needed to better use aug-mentation for cotton pests. The thirdmethod is importation, which involves theintroduction of natural enemies from otherareas of the world for pests that do notalready have effective natural enemies. Thismethod requires some time to complete(usually a number of years), as appropriate

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organisms must be located, tested for safe-ty, and released. Although this method hasbeen quite successful in some instances, ithas also failed in a number of others.Where successful, it usually provides per-manent full or partial control of the pest.

Sampling for Natural EnemiesThere are various methods in use for

sampling natural enemies in cotton. It isbeyond the scope of this text to present afull discussion of those methods, withtheir pros and cons. We will present a fewof the more widely used methods here forconsideration.

Direct Observation: This method involves simply looking fornatural enemies during the process ofscouting. It does not require any additionaleffort. But it also tends to miss many ofthe natural enemies. More mobile specieswill move away or drop from the plantquite rapidly as you approach.

Drop Cloth or Shake Cloth: This method uses a 3x3 foot squaredurable cloth, and 2 dowels (usually about1/2 inch in diameter, 36-48 inches long).The dowels are anchored parallel to oneanother along each of two sides of thecloth (usually through a loop stitched inthe cloth), forming something resemblinga square stretcher. To sample with the

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cloth, spread the cloth between two rowsof cotton, then vigorously shake about 3feet of row, on one or both sides of thecloth, onto the cloth. The insects on thecloth can then be counted. This method isreasonably effective at sampling variousnatural enemies, although some naturalenemies (such as green lacewing larvaeand big-eyed bug adults) are not well sam-pled using this approach. In addition, thedisturbance of the plants prior to shakingcan cause mobile species to take off.Counts should be done quickly after shak-ing as some insects will rapidly leave thecloth. This problem is particularly apparentwhen sampling on warm afternoons. Thismethod can also be quite unpleasant infields infested with fire ants, as the sam-pler must get down on the ground to sam-ple, and can become quickly involved withangry fire ants.

Beat Bucket:This method requires a large bucket, suchas a 5-gallon bucket; preferably one that iswhite or light colored. The approach issimilar to that of the shake cloth: a singleplant is gently bent into the bucket andshaken vigorously. The plant is then quick-ly removed and the insects and spiderscounted. The beat bucket is somewhatmore effective than is the shake cloth atdislodging natural enemies, but requiresmore time to sample the same area as canbe done with the shake cloth. Like the shake

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cloth, some of the mobile species will takeoff before the shaking can get started. Thebucket is, however, easy to carry and use.

Sweep Sampling: A heavy-duty sweep net (usually made ofmuslin or canvas) can be used to collectnatural enemies. The net is swung rapidlyback and forth in a sweep through the cot-ton, and the contents of the net bag arethen examined for insects. This method isgood for collecting some of the moremobile species, but overall is one of theleast accurate sampling methods becauseof variability in sampling efficiency due toplant height and density, differences inspeed of the sweeps, and tendency of nat-ural enemies to change their locations inthe plant throughout the day.

Vacuum Sampling: Vacuum samplers are available that suckinto bags most everything from on andaround a single plant or plant part. Mostof these samplers are impractical for regu-lar use in sampling, and the samples areterribly messy to process (they usuallycontain quite a bit of dirt and debris). Inaddition, the efficiency of vacuum sam-pling drops considerably as the cottonplant grows. The act of placing the vacu-um funnel over the plant can also disturband scatter mobile species.

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FURTHER READINGThe following publications provide addi-tional information on natural enemies ofcotton insect pests:

Integrated Pest Management for Cotton.University of California Division ofAgriculture and Natural ResourcesPublication 3305. To order, 510-642-2431.

Biology, Predation Ecology andSignificance of Spiders in Texas CottonEcosystems with a Key to Species. 1993.Texas Ag. Exp. Sta. Bull. B-1711. 115 pp.

Identification, Biology and Sampling ofCotton Insects. B-933. Texas Ag. Ext.Service. College Station, TX. To order, con-tact Publication and Supply Distribution,P.O. Box 1209, Bryan, TX 77806-1209

Educational programs conducted by TexasCooperative Extension serve people of allages regardless of socioeconomic level,race, color, sex, religion, handicap ornational origin.

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Pest

Spe

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B--60476 7/8/05 1:17 PM

17

bugs

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B--60476 7/8/05 1:17 PM

18

Pin

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ute

B--60476 7/8/05 1:17 PM

19

pira

te b

ug (

E,L)

, In

sidi

ous

flow

er b

ug (

E,L)

, D

amse

l bu

gs (

E,L)

, Sp

ined

sold

ier

bug

(L),

Fir

e an

ts (

E,L)

, C

ollo

ps b

eetle

(E),

Ear

wig

s (E

),

Gro

und

beet

les

(E,L

), T

rich

ogra

mm

a (E

), C

otes

ia m

argi

niv

entr

is (

L),

Met

eoru

s(L

), C

opid

osom

a(E

), N

ucle

ar p

olyh

edro

sis

viru

s (L

)

Eu

rope

an C

orn

M

acro

centr

us g

randi

i(L

)B

orer

Stin

k B

ugs

Tele

nom

us w

asps

(E),

Tri

ssol

cus

was

ps (

E)

Spid

er M

ites

Six-

spot

ted

thri

ps (

E),

Wes

tern

pre

dato

ry m

ite

(E,N

,A),

Ste

thor

us

(E,N

,A),

Min

ute

pira

te b

ug (

E,N

,A),

Ins

idio

us f

low

er b

ug (

E,N

,A),

G

reen

lac

ewin

gs (

E,N

,A)

Wh

itef

lies

Min

ute

pira

te b

ug (

N,A

), G

reen

lac

ewin

gs (

N,A

), C

ollo

ps b

eetles

(N

,A),

Big

-eye

d bu

gs (

N,A

), W

hite

fly p

aras

ites

(N),

Con

verg

ent la

dy b

eetle

s (N

,A).

Pare

nthe

tica

l le

tter

s de

sign

ate

life

stag

es o

f th

e pe

st a

ttac

ked

by t

he n

atur

al e

nem

y: (

E) =

egg

s,(N

) =

nym

phs,

(L)

= l

arva

e,

(A)

= a

dults

B--60476 7/8/05 1:17 PM

20

Pesticides and Natural EnemiesIn this book, we have attempted to provide

some general information on the toxicity ofinsecticides to the various natural enemies.However, for most of the natural enemies pre-sented there is little information available onpesticide effects. These effects also vary withthe pesticide used, the rate and volumeapplied, the timing of the application, theequipment used, the size of the plants, and theenvironmental conditions. Further, toxicitytests are often conducted with only one or afew representative pesticides within a particu-lar pesticide class. It is not possible at presentto state for each natural enemy how everyavailable pesticide will affect it. Also, severalnew insecticide classes (imidacloprid, spin-osads, pyrroles, and insect growth regulators)have recently been introduced and have notbeen fully evaluated for their impact on benefi-cial insects and spiders.

The various classes of insecticides (see theTable) differ in their toxicity to natural ene-mies. Generally, the most toxic compounds arethe organophosphates. These materials have abroad range of toxicity and are typically quitetoxic to natural enemies. There is some evi-dence that rate reductions can reduce the toxi-city of these compounds to some degree buteven then they remain highly toxic relative toother insecticide classes. Some organophos-phates (e.g., methyl parathion) have shortresidual toxicity that renders a field safe for

B--60476 7/8/05 1:17 PM

21

recolonization by natural enemies only a shorttime after treatment. Pyrethroids tend to bemore selective than organophosphates to nat-ural enemies. They are, however, still quitetoxic to many natural enemies. Some of themore recently developed pyrethroids are partic-ularly toxic, approaching the activity of themore toxic organophosphates. Repeated appli-cations of pyrethroids can have a devastatingcumulative effect on natural enemy popula-tions. Carbamates are quite variable in theirselectivity, but tend to be less toxic to naturalenemies than are the organophosphates orpyrethroids. Their toxicity varies with rate andmaterial — some compounds are quite toxic toa wide range of natural enemies. Cyclodienesexhibit moderate to high selectivity, and can bequite useful for conserving some natural ene-mies while killing the targeted pest(s). Insectgrowth regulators are quite generally selectivein their toxicity, and tend to have limited nega-tive effects on natural enemy populations. Bt’sare highly specific to target pests, and as suchare quite safe for natural enemies. Informationis still being gathered on imidacloprids,pyrroles, spinosads, and pyrazoles. The lattertwo classes appear to be less toxic to a numberof natural enemies than are organophosphates,pyrethroids, and carbamates. Formamidinesvary in toxicity to natural enemies, but aremoderately to highly toxic at larvicidal rates. Atovicidal rates, toxicity to some natural enemiescan be reduced.

Using in-furrow or soil-applied systemic pes-ticides may have advantages for natural ene-

B--60476 7/8/05 1:17 PM

mies by reducing direct exposure of the pesti-cide to the natural enemies. There is some evi-dence, however, that systemic pesticides can stillcause problems. Reduced natural enemy popu-lations are often observed where systemic insec-ticides are used, particularly when high ratesare applied. Cotton produces nectar, and if thepesticide concentrates in the nectar it could bedeadly for those insects that feed on it. In addi-tion, many natural enemies occasionally suckon plant juices (such as the pirate bugs, big-eyed bugs, damsel bugs, and assassin bugs).They may pick up deadly amounts of insecticidewhile feeding.

All chemicals used in cotton production havethe potential to influence natural enemies, fromherbicides and fungicides to plant growth regu-lators and defoliants. Effects of these otherchemicals on natural enemies are poorlyknown, although in some cases, such as withthe arsenical herbicide MSMA, dramatic reduc-tions in natural enemies frequently follow appli-cation.

Besides toxic effects, pesticides can also exertwhat are termed “sublethal effects.” Theseeffects are not expressed as mortality, but ratheras changes in the insect’s behavior and/or phys-iology. The changes, which by the way are notalways bad, may occur in such things as theinsect’s movement, reproduction, development,feeding, egg laying ability, and rates at whicheggs hatch. Such effects are more difficult tostudy than mortality, so they have not receivedmuch attention. Nevertheless, they can be very

22

B--60476 7/8/05 1:17 PM

23

impo

rtan

t.

Che

mic

al C

lass

Cot

ton

Inse

ctic

ides

in

the

Cla

ssO

rgan

oph

osph

ates

Bid

rin®

, B

olst

ar®,

Cur

acro

n®,

Cyg

on®,

Cyt

hion

®, D

anitol

®,

Dim

ate®

, D

imet

hoat

e®,

Di-

Syst

on®,

Gut

hion

®, L

orsb

an®,

M

alat

hion

, M

etas

ysto

x®,

Met

hyl

para

thio

n, O

rthe

ne®,

Pa

rath

ion®

, Pa

yloa

d®,

Penn

cap-

M®,

Thi

met

® M

onitor

®,

Supr

acid

e®

Pyr

eth

roid

sA

mbu

sh®,

Am

mo®

, A

sana

®, B

ayth

roid

®, C

aptu

re®,

Dec

is®,

Fu

ry®,

Kar

ate®

, Po

unce

®, S

cout

X-t

ra®,

Dan

itol

®

Car

bam

ates

Lann

ate®

, La

rvin

®, S

evin

®, T

emik

®, V

ydat

e®

Cyc

lodi

enes

Com

ite®

, K

elth

ane®

, Ph

aser

®, T

hiod

an®

Inse

ct G

row

th R

egu

lato

rsC

onfirm

®, D

imili

n®

Bt’

sA

gree

®, C

ondo

r®,

Des

ign®

, D

ipel

®, J

avel

in®,

MV

P®,

Xen

tari

®

Imid

aclo

prid

sG

auch

o®,

Prov

ado®

Oth

er C

lass

esFo

rmam

idin

es:

Ova

syn®

, Py

rrol

es:

Pira

te®,

Spi

nosa

ds:

Trac

er®,

B--60476 7/8/05 1:17 PM

24

LynxSpidersOxyopes salticusPeucetia viridans

Characteristics: The striped lynx, Oxyopessalticus, and the green lynx, Peucetia viridans,are common spiders in cotton and are foundthroughout the Cotton Belt. The striped lynxis brown, about 1/4 inch long with 4 long,gray stripes behind the head on the front halfof the body. The green lynx is a bright greenspider about 1/2-3/4 inch long with small redspots on the legs and abdomen. Both specieshave eight eyes and two black lines runningdown the face and jaws, and the end of theabdomen is pointed. The legs are long andthin and armed with many long spines. Theyoften run and jump erratically when dis-turbed.

Prey: Lynx spiders are probably the mostimportant spiders in cotton because of theirwide distribution and abundance. They areactive and aggressive hunters that chase theirprey or hide in wait and leap out. They donot build webs. Lynx spiders feed on a widevariety of insects, both pests (fleahoppers,bollworm/tobacco budworm larvae and eggs)and occasionally, beneficials. The striped lynxis a key predator of the cotton fleahopper.

General Biology: Spiders “balloon” into cot-ton fields by floating on wind-blown strandsof silk. The egg-sac of the striped lynx is disc-shaped and attached to a leaf. The femaleguards the egg-sac until the spiderlingsemerge. Reproduction occurs throughout thegrowing season and there are one or two gen-

B--60476 7/8/05 1:17 PM

25

erations per year. The green lynx produces astraw-colored egg-sac in the fall and guards ituntil the spiderlings emerge about 4 weekslater. Immature spiders overwinter and maturein July and August. The life cycle from egghatch to mature adult is about 300 days. Thereis one generation a year.

Striped lynxspider

Green lynxspider W

. St

erlin

gW

. St

erlin

g

B--60476 7/8/05 1:17 PM

26

Celer CrabSpider

Misumenops celer

Characteristics: Crab spiders can be identi-fied by their front legs which are much longerand more robust than the other legs, giving ita crab-like appearance. Crab spiders alsomove quickly backwards or sideways like acrab, facing their antagonist or prey. The celercrab spider is a common species in cottonand in some cases is the most abundant spi-der species present. The color of the femaleranges from dull to bright yellow to white.There is an X-shaped mark on the back. Themale has red along the edges of its body. Insome individuals, two black or red bands arepresent on the abdomen. Several otherspecies of crab spiders are found in cotton,including M. formosipes, a large specieswhich changes color to match its surround-ings.

Prey: Crab spiders feed on many cotton pestsand occasionally on beneficial insects. Crabspiders do not build webs but wait to ambushpassing insects using their strong legs andvenom.

General Biology: Celer crab spiders are foundin other crops and uncultivated areas and arecarried into cotton fields on strands of silk bybreezes early in the season. There are 1 or 2generations per year.

B--60476 7/8/05 1:17 PM

27

Celer crab spider W

. St

erlin

g

B--60476 7/8/05 1:17 PM

28

JumpingSpiders

Family: Salticidae

Characteristics: Jumping spiders have com-pact, rectangular bodies with short, powerfullegs. Their eyes are organized into three rows.The front portion of their body is as large orlarger than the rear portion (abdomen). Theyrange in size from 1/8 to 1/2 inch. Color ishighly variable depending upon species. Somespecies have bright iridescent scales that givethem a metallic green or purplish appearance.A commonly seen species, Phidippus audax,is a large, black and hairy spider with a largewhite spot on its back. All jumping spidershave large eyes that provide excellent eyesightfor visually locating and pursuing prey. Trueto their name, they quickly jump when dis-turbed or when attacking prey. Jumping spi-ders are found throughout the Cotton Belt.

Prey: Jumping spiders feed on a wide varietyof pest insects and occasionally beneficialinsects. Adults can capture large caterpillarsand boll weevil adults and are importantpredators of fleahoppers. Jumping spiders willalso feed on moth eggs.

General Biology: Jumping spiders have excel-lent eyesight which they use to stalk and cap-ture their prey with a sudden pounce.Females place their egg sacks inside nests ofsilk and remain with them until the spider-lings hatch and disperse. One generation iscompleted each year.

B--60476 7/8/05 1:17 PM

29

Black andwhitejumpingspider

Photo: A72.Anotherspecies ofjumping spider

W.

Ster

ling

W.

Ster

ling

B--60476 7/8/05 1:17 PM

30

GreenLacewings

Chrysoperla carneaChrysoperla rufilabrisChrysopa nigricornis

Chrysopa oculata

Characteristics: Adults are delicate, slen-der insects 1/2 to 3/4 inch long, greenwith golden eyes and long antennae. Thelarge, delicate wings are laced with a net-work of veins and are held roof-like overthe back. Larvae are alligator-shaped,grayish-brown with long sickle-shapedmandibles projecting from the head. Fullgrown larvae are 1/2 to 3/8 inch long.Eggs are laid singly on top of a fine threadattached to leaves or stems except those ofC. nigricornis which are also attached tostalks, but are deposited in a large, tightcluster. Adult Chrysopa species release apungent odor when handled. C. carnea isfound throughout the Cotton Belt while C.rufilabris is found from Texas eastward.Various other species of Chrysoperla andChrysopa can be found in cotton.

Prey: Larvae are important predators ofaphids, mites, whiteflies, and eggs andsmall larvae of bollworms, budworms,armyworms, and loopers. They also feedon other lacewing larvae. Lacewingsbecome very abundant when aphids arepresent. Like their larvae, adult Chrysopa

B--60476 7/8/05 1:17 PM

31

Greenlacewingegg

Larva ofthe greenlacewing

J.K

. C

lark

, U

niv.

CA

W.

Ster

ling

B--60476 7/8/05 1:17 PM

32

GreenLacewings

(Continued)

species also feed on insects, while adultsof the Chrysoperla species feed only onhoneydew, nectar and pollen.

General Biology: Eggs hatch in 3-6 days.Larvae feed for 2 weeks and then spinspherical, white cocoons of tough silkwhich are found behind bracts and in plantterminals. Larvae pupate inside thecocoons and the adults emerge in about 2weeks. Adults fly at night and may travelseveral miles during the first 2-3 nightsafter emergence. Females lay their firsteggs 4-6 days after emergence, produce atotal of 200-800 eggs, and live for severalweeks. C. carnea and C. rufilabris overwin-ter as adults while Chrysopa nigricornisand oculata overwinter as pupae incocoons.

B--60476 7/8/05 1:17 PM

Pupa ofthe greenlacewing

Adultgreenlacewing

33

J.K

. C

lark

, U

niv.

CA

W.

Ster

ling

B--60476 7/8/05 1:17 PM

34

BrownLacewings

Hemerobius speciesMicromus species

Characteristics: Adults are similar in appear-ance to the adult green lacewing but aresmaller, brown and appear to be hairy. Larvaeare reddish-brown with two to four whitespots in the middle of the body. Like greenlacewing larvae, they are alligator shapedwith long, sickle like mouthparts used to suckjuices from their prey. Brown lacewing larvaehave a characteristic side-to-side “head-wag-ging” behavior which also distinguishes themfrom green lacewing larvae. Brown lacewingscan be found throughout the Cotton Belt.

Prey: Adults and larvae feed on aphids andwhiteflies. Larvae have been observed feedingon a variety of pest eggs, including boll-worms, budworms, loopers and armyworms.

General Biology: Unlike the green lacewing,brown lacewing eggs are not placed on astalk. Eggs are laid on the underside of leavesand turn from a cream color to pink or purplebefore hatching. Full grown larvae pupateinside an elliptical cocoon (in concealed loca-tions, such as within bracts) made of looselywoven silk through which the pupa is visible.Adults fly during the evening and at night.Brown lacewings tend to be more abundantwhen weather conditions are cool, when rainis frequent, and when the plant canopy clos-es. Most species have 2 or 3 generations peryear.

B--60476 7/8/05 1:17 PM

Photo:A93.Brownlacewingadult

Photo: B65Larva of abrownlacewing

Photo: B12.Pupa of abrownlacewing

35

Uni

v. F

lori

da,

Dep

t. E

ntom

olog

yU

niv.

Flo

rida

, D

ept.

Ent

omol

ogy

J. R

uber

son

B--60476 7/8/05 1:18 PM

36

Ground andTiger Beetles

Carabidae: Calasoma speciesLebia species

Pterostichus speciesCicindelidae: Cicindela species

Megacephala species

Characteristics: Ground beetles are dark andshiny with long, slender legs and antennae,and prominent eyes. These beetles run quick-ly but many species are not commonly seenbecause they are most active at night.Immatures are worm-like predators with welldeveloped legs and jaws. Both stages areactive on the soil surface or may climb intothe plant canopy in search of prey.

Tiger beetle adults are active during the day,and run and fly very quickly. They can oftenbe seen running on sandy soils and openareas between rows of cotton or along fieldmargins. They have long legs and hold theirbodies well off the ground when standing orrunning. Tiger beetles quickly fly ifapproached too closely but often land a shortdistance away. Unlike most ground beetles,tiger beetles have heads that are wider thantheir thoraxes.

Prey: Adults and larval ground beetles huntcaterpillars, including cutworms and boll-worms that drop to the soil to pupate, andother insects in the soil. Some species such asLebia climb the cotton plant in search ofcaterpillars. Tiger beetle adults feed on thesame types of prey as ground beetles. Larvaltiger beetles feed on insects active on theground.

B--60476 7/8/05 1:18 PM

37

Adultgroundbeetle

AdultCalasomaground beetle

W.

Ster

ling

Uni

v. F

lori

da,

Ento

mol

ogy

Dep

t.

B--60476 7/8/05 1:18 PM

Ground andTiger Beetles

(Continued)

General Biology: A large number of speciesfall into this group and their biologies varywidely. Ground beetles hide in soil cracks andunder loose soil during the day and hunt forprey at night. Field margins and borders canbe very important refuge habitats for groundbeetles which move into cotton fields insearch of food. Eggs are laid in or on soil.Larvae are also active on the soil surface, butsome will climb plants in search of prey.Larval tiger beetles construct small tunnelsand turrets in the soil, from which they cap-ture passing insects.

38

B--60476 7/8/05 1:18 PM

Larva ofa groundbeetle

Adulttigerbeetle

39

W.

Ster

ling

Uni

v. F

lori

da,

Ento

mol

ogy

Dep

t.

B--60476 7/8/05 1:18 PM

40

Seven-spottedLady Beetle or

“C-7” Coccinella septempunctata

Characteristics: The seven-spotted lady bee-tle is a large (1/3 inch long), orange-red ladybeetle with seven, distinct dark spots on theforewings (back). The shield behind the head(pronotum) is black with a white mark oneach side. Larvae are alligator-shaped andblack with an orange-white strip down themiddle of the thorax (central body regionwhere legs are attached). Full grown larvaeare about 1/2 inch long. This species is foundthroughout the eastern U.S. west toOklahoma and Texas.

Prey: Both adults and larvae feed primarilyon aphids but will also prey on eggs andcaterpillars of various moth pests. Like theconvergent lady beetle, the seven-spotted ismost abundant in cotton when aphids arepresent. Adults can survive on pollen andnectar when aphids are absent.

General Biology: This species was introducedinto the U.S. from Europe. Eggs are yellow-orange, football-shaped and laid on end ingroups of 10-30. Each female can deposit upto 1,000 eggs during a 6-8 week period. Eggshatch in 7-10 days. Larvae are full grown in10-50 days, depending on temperature andavailability of food. Pupae are black withspots of yellow. Adults emerge in 3-10 days.The life cycle is completed in about 2-3weeks, and there are several generations each

B--60476 7/8/05 1:18 PM

41

year. Small groups of adult beetles gather inprotected areas to overwinter.

Adultseven-spottedlady beetle

Seven-spottedlady bee-tle larva

Uni

v. F

lori

da,

Ento

mol

ogy

Dep

t.D

. St

eink

raus

B--60476 7/8/05 1:18 PM

42

Harmonia orAsian Lady

Beetle Harmonia axyridis

Characteristics: Adults are a bright yellow-orange to reddish orange to red. The numberof spots varies from 0 to 20. A black “M”shaped mark or solid mark in the center ofthe white pronotum (shield-like area justbehind the head) identifies the harmonia orAsian lady beetle. The two large white areason each side of the pronotum create theappearance of two large “eyes.” Larvae arealligator-shaped, black, with an orange jaggedstreak or blaze on each side of the abdomen.Eggs are yellow, football-shaped and laid inmasses of 10-30 on leaves. H. axyridis isfound throughout the southeastern U.S. tocentral Texas.

Prey: Both adults and larvae feed primarilyon aphids but also feed on armyworm eggsand small caterpillars.

General Biology: The harmonia lady beetlewas introduced into the U.S. to control aphidson pecan trees. It commonly moves into cot-ton when cotton aphids are abundant. Eggshatch in 4 days and larvae feed for about 2weeks and then enter the pupal stage. Afterabout 6 days, the adult emerges. Femalesbegin laying eggs 7-12 days later and eachcan produce 500-700 eggs. Adults live 30-80days under laboratory conditions. Adultsoverwinter in masses in protected areas,sometimes becoming a nuisance in homes.

B--60476 7/8/05 1:18 PM

43

Adult harmo-nia or Asianlady beetle

Adults ofthe harmo-nia orAsian ladybeetlesshowingvariationin colorpattern

Larva of theharmonia orAsian ladybeetle

M.

Mer

chan

tB.

Ree

A.

Knu

tson

B--60476 7/8/05 1:18 PM

44

ConvergentLady Beetle

Hippodamia convergens

Characteristics: The convergent lady beetle isnamed for the two white lines on the pronotum(plate behind the head) that, if extended,would converge. The margin of the pronotum isalso lined with white. The number of blackdots on the adults ranges from only a few up to13. Larvae are alligator-shaped and black withrows of orange spots. Eggs are bright yellow,football-shaped and laid in clusters of 10 ormore on plants or on debris on the soil. Pupaeare immobile, attached to the plant, and resem-ble spotted bike helmets. The convergent ladybeetle is found throughout the U.S. and is oneof the most common lady beetles in cotton.

Prey: Adults and larvae feed primarily onaphids. When aphids are not available, adultsfeed on bollworm and budworm eggs and smalllarvae. Convergent lady beetles and larvae canbecome very abundant when aphids are pre-sent. Adults also feed on nectar and pollen.

General Biology: Females lay 200-1,000 eggsduring a 1- to 3-month life span. Eggs hatch in3-4 days and larvae feed for 2-3 weeks andthen enter the pupal stage. Pupae are immobileand attached to stems and leaves. Adultsemerge from the pupae in about a week. Thereare several generations per year. Adults congre-gate in sheltered sites to overwinter.

B--60476 7/8/05 1:18 PM

45

Adult conver-gent ladybeetle

Convergentlady beetlelarva

Pupa andadult of theconvergentlady beetle A

. K

nuts

onJ.

K.

Cla

rk,

Uni

v. C

AJ.

K.

Cla

rk,

Uni

v. C

A

B--60476 7/8/05 1:18 PM

46

Pink SpottedLady Beetle

Coleomegilla maculata

Characteristics: The pink spotted lady beetleis a slender, pink beetle with six very largeblack spots on each forewing. The spotssometimes join. There are two large triangularblack marks on the area just behind the head.Larvae are alligator-shaped and black withcream or yellow spots. Eggs are yellow andfootball-shaped and laid on end in masses of10-30. The pink spotted lady beetle is foundthroughout the eastern half of the U.S. to eastTexas and only along the southern border ofwest Texas, New Mexico, Arizona andCalifornia.

Prey: Adults and larvae feed primarily onaphids but may also feed on eggs and smallcaterpillars. Adults feed heavily on pollen andmay become abundant when cotton is bloom-ing.

General Biology: Adults emerge from over-wintering sites in the spring and lay eggmasses on leaves often near aphid colonies.Females lay several hundred eggs during a 2-3month period. Larvae feed for several weeksand then molt to the pupal stage. The pupa isattached to a leaf or stem and does not move.The adult beetle emerges from the pupa inabout a week. There are several generationseach year, and adults overwinter in protectedsites.

B--60476 7/8/05 1:18 PM

47

Lady beetleeggs

Pink spottedlady beetle W

. St

erlin

gJ.

K.

Cla

rk,

Uni

v. C

A

B--60476 7/8/05 1:18 PM

48

CollopsBeetles

Collops quadrimaculatusCollops vittatus

Collops balteatusCollops marginellus

Characteristics: These are active, soft-bodiedbeetles. They are dark blue with orange spotsor stripes. C. quadrimaculatus is often calledthe ‘red-cross’ beetle because of the orange-red cross on its back. C. vittatus is dark bluewith an orange stripe on each side. The frontsection of the thorax of these beetles is oftenorange and may or may not have a centraldark spot. Larvae have a pincher-like struc-ture at the tip of the abdomen and are rarelyseen. In California and Arizona, C. marginel-lus and C. vittatus are important species incotton.

Prey: Adults feed on moth eggs and smallcaterpillars, aphids, whiteflies, spider mites,aphids and stink bug eggs. C. quadrimacula-tus commonly feeds on bollworm eggs andlarvae. In Arizona, C. vittatus feeds on white-flies in cotton.

General Biology: Eggs are yellow to pinkish-orange and spindle-shaped. Most eggs are laidin clusters on soil debris but sometimes arefound in the plant terminal. Larvae are pinkto brownish-red and feed on insects in thesoil. These beetles overwinter as adults.

B--60476 7/8/05 1:18 PM

49

Collopsbalteatus

W.

Ster

ling

B--60476 7/8/05 1:18 PM

50

HoodedBeetle

Notoxus monodon Notoxus species

Characteristics: When viewed from the sidewith a hand lens, the hooded beetle is easilyrecognized by the horn-like projection whichextends over its head, creating a “hood.”These small, ant-like beetles are tan or red-dish with black patches, often forming zig-zag patterns on the back (elytra).

Prey: Feeding habits of this insect in cottonare not well known. Adults feed on nectar,and under laboratory conditions, readily feedon budworm and bollworm eggs and smalllarvae.

General Biology: Adults are often found hid-den behind bracts on squares or nestled interminals. Larvae live in sandy soil. They arebelieved to complete several generations ayear and overwinter as adults.

B--60476 7/8/05 1:18 PM

51

Adulthoodedbeetle D

. W

ater

s, U

niv.

GA

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52

StripedEarwigLabidura riparia

Characteristics: The striped earwig is a slen-der, flattened insect 3/4-1 inch long withlarge pinchers at the tip of the abdomen. Thetwo lengthwise stripes on the front of the tho-rax (pronotum) help identify L. riparia.Immature earwigs resemble adults but aresmaller. Earwigs are active at night andsearch for food both on the soil and onplants. During the day they hide in soilcrevices and thus are seldom seen. L. ripariais found along the East Coast to Florida andwest to California.

Prey: Earwigs are important predators ofeggs, larvae, and pupae of many differentkinds of moths and beetles.

General Biology: Females deposit eggs innests constructed in the soil and care for theeggs and nymphs. Development of egg toadult requires about 4 months, and there are1 or 2 generations per year. Studies in Georgiafound L. riparia less common in cotton fieldswhere fire ants were present.

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Adultearwigtendingeggs

Adultearwig

M.

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Univ. Florida, Entomology Dept.

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RoveBeetles

Family:Staphylinidae

Characteristics: Adults are tiny to small,black to brown slender beetles which run andfly rapidly. The wings are very small, leavingmuch of the abdomen exposed. The tip of theabdomen may be curled forward, much like ascorpion, when the beetles are disturbed,although the beetles have no stinger. Larvaeare elongate with well developed legs.

Prey: Adults and larvae feed on a variety ofsmall, soft-bodied insects and insect eggs.Some species feed on aphids, others on cater-pillars or spiders. Little is known about thespecies present in cotton. Larvae commonlylive in the soil while larvae of some speciesare parasites of insects.

General Biology: The rove beetle family con-tains a large number of species. Little isknown about most species, especially thosefound in cotton. One species common in theSoutheast can be found in cotton blooms.

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Adult rovebeetle (noteshort wingcovers) J.

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DamselBugs

Nabis roseipennisNabis capsiformis

Nabis americoferusNabis ferus

Nabis alternatusNabicula species

Characteristics: Damsel bugs, also callednabids, are slender, dull tan to gray, some-times black, insects about 3/8 to 1/2 inchlong with long antennae and legs, and promi-nent eyes. Damsel bugs are shaped like someassassin bugs but are smaller and less color-ful. Like assassin bugs, damsel bugs have anarrow head and a long beak and can inflicta painful bite. However, unlike assassin bugs,the damsel bug’s neck is wider than its head.Nymphs look like small adults without wings.Damsel bugs of various species occurthroughout the Cotton Belt.

Prey: Damsel bugs feed on moth eggs andsmall larvae, aphids, fleahoppers, lygus andtarnished plant bugs, whiteflies, mites andoccasionally other predatory insects such aslacewing larvae, pirate bugs, and big-eyedbugs.

General Biology: Eggs are white and cylindri-cal, and are inserted into stems with only theegg’s end (or cap) visible above the surface.Eggs hatch in 8-12 days and nymphs developin 3-4 weeks. Females produce 150-300 eggs.There are 2 or 3 generations per year andadults overwinter in a variety of shelteredareas.

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Damselbug adultandnymph J.

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SpinedSoldier Bug

Podisus maculiventris

Characteristics: Adults of this stink bug arepale brown, about 3/8 to 1/2 inch long andlook like other stink bugs. This insect isnamed for the single, large spine on each“shoulder.” Adults resemble members of theplant-feeding brown stink bug group(Euschistus) but the shoulder spines are morepronounced on the spined soldier bug thanon most brown stink bugs. There are somepest species, however, that closely resemblethis predator. The most reliable way to distin-guish between plant-feeding and predatorystink bugs is to examine the straw-likemouthparts (beak). Flip the stink bug overand look at its mouthparts (see drawings onthe next page). If the mouthparts are broad(roughly twice the width of an antenna) andstout, it is a predatory species. If the mouth-parts are slender (about the width of anantenna) then it is a plant-feeding stink bug.

Like other stink bugs, Podisus emits a strongodor when disturbed. Eggs of the spined sol-dier bug are metallic silver or gold, with afringe or crown of hairs about the top.Nymphs are oval-shaped and black withbands of red, yellow-orange and cream on theabdomen. This predator occurs throughoutthe Cotton Belt.

Prey: Adults and nymphs feed primarily oncaterpillars. Occasionally they may attackbeneficial insects and spiders in cotton. Youngnymphs often “gang up” on larger prey.

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Eggs ofthespinedsoldierbug

Predatory stinkbug

Plant-feedingstinkbug

W.

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SpinedSoldier Bug

(Continued)

General Biology: Eggs are barrel-shaped andlaid in tight clusters of 20-30 on leaves andtwigs. Newly hatched nymphs remain clus-tered around the egg mass before dispersing.Young nymphs feed only on plant sap whileolder nymphs and adults feed on insects.Development from egg to adult requires about3 weeks. Adults live 1-2 months and femalesdeposit 200-300 eggs. Spined soldier bugs aremore common when caterpillars are present.

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Nymph ofthespinedsoldierbug

Adultspinedsoldierbug feed-ing on abollworm W

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SpinedAssassin

Bugs Sinea diadema

Characteristics: Spined assassin bugs areslow moving, medium to large bugs (1/2 to3/4 inch long) with a long, curved beak heldbeneath the body. The front legs are enlargedand spined for grasping prey, and spines arealso present on the thorax. Color varies fromblack to reddish-brown. The head is narrowand antennae and legs are long and slender.Nymphs resemble adults but lack wings.When disturbed, these bugs will often archback, pulling their forelegs up and back in adefensive posture. The spined assassin bug,Sinea diadema, is found throughout theCotton Belt. Other species of Sinea that maybe found in cotton include S. confusa, S. com-plexa and S. spinipes.

Prey: Assassin bug nymphs and adults eat avariety of prey including caterpillars, aphidsand many other insects, such as lady beetleadults and spiders.

General Biology: Eggs resemble those of theleafhopper assassin bug — they are barrel-shaped and laid upright in tight clusters or inrows on leaves or stems. However, the top orcap of the egg may be shaped in bizarreshapes or ornamentations, unlike that of theleafhopper assassin bug. Eggs hatch in about14 days, and nymphs require 25-35 days tocomplete development. Adults live 1-2months and females lay up to 300 eggs. These

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predators typically sit and wait to attack pass-ing prey.

Spinedassassinbug,Sineadiadema W

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LeafhopperAssassin

BugZelus renardiiZelus species

Characteristics: This assassin bug, Zelusrenardii, is slender, about 1/2 inch long, andyellowish-green to red and brown in color.The head is very narrow and is armed with alarge, strong beak. The nymph resembles theadult but is smaller and lacks wings. Otherrelated assassin bug species include Zelusexsanguis, Z. cervicalis, Z. socius, Z. tetracan-thus and Z. bilobus.

Prey: Assassin bugs attack moving prey andboth adults and nymphs eat a variety ofinsects, both pest and beneficial. Assassinbugs are one of the few predators in cottonthat can capture large caterpillars and adultboll weevils.

General Biology: Eggs are dark shiny brownwith white caps and laid in tight clusters oncotton plants. The front legs of nymphs andadults are coated with a sticky substancebelieved to be used for capturing prey. Theyoften have debris stuck to these legs. Thesepredators are usually only abundant aftermid-summer.

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Egg mass ofZelus renardii

Leafhopperassassinbug feedingon boll-worm W

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Big-eyed BugsGeocoris punctipes

Geocoris uliginosusGeocoris pallens

Characteristics: Adults and nymphs havebroad heads and large, bulging eyes. Geocorispunctipes is common throughout the CottonBelt. Adults of Geocoris punctipes are about3/16 inch long and silvery grey. Adults ofGeocoris uliginosus are smaller (1/8 inchlong), oval and black to reddish-black.Geocoris pallens is slender, varies in colorfrom buff to yellow-brown to black and isfound from Arkansas to California. Nymphsof all species look like small adults withoutwings and can be mistaken for chinch bugs.Big-eyed bug nymphs, when crushed, releasea strong, offensive “stink bug” odor. Bothadults and nymphs run rapidly with a distinc-tive “swagger” and often fall from the plantwhen disturbed.

Prey: Big-eyed bug adults and nymphs areimportant predators of many cotton insectpests including bollworm and budworm eggs,small caterpillars, whiteflies, plant bugs,aphids and mites. Big-eyed bugs feed on cot-ton nectar and occasionally plant sap.

General Biology: Eggs are deposited singlyand are easily seen on leaves and stems ofthe cotton plant. Eggs are grayish-white topink and shaped like a hot-dog. A bright redeyespot develops a few days after the egg islaid. Eggs hatch in 5-8 days. Developmentfrom egg to adult requires about 3-4 weeks.Females produce 150-300 eggs and live 3-4weeks. All species overwinter as adults.

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Adult big-eyed bug,Geocorispunctipes

Nymph ofGeocorispunctipesfeeding onbollwormeggs

Big-eyed bug,Geocoris ulig-inosus, feed-ing on cater-pillar

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Hover orSyrphid Fly

Syrphus species

Characteristics: The larva is a green to brownslug-like maggot with no legs and no obvioushead. The tiny head is located at the smallend of the tapered body. Although they haveno legs, larvae can move well, stretching outtheir bodies in a looping action. Full grownlarvae are about 1/4-1/2 inch long. Adultsvary in size (from 1/4 to 1/2 inch long) andare striped with bright yellow and black.Some species have a slender, striped body,while others have a broad, striped abdomenand look like a bee. When at rest, the wingsare held out at an angle from the body, unlikebees and wasps which fold their wings overtheir backs. Adults fly quickly and can oftenbe seen hovering near plants and flowers,hence their common name.

Prey: Hover fly larvae pierce their prey andsuck out the body fluids. They feed most com-monly on aphids, but may also consume motheggs and sometimes small caterpillars. Theadult flies feed only on nectar and honeydew.

General Biology: Eggs are white, sculptured,and elongate, and are laid on leaves nearaphid colonies. Larvae swing their heads fromside to side until they touch and seize anaphid. The larva then lifts the aphid into theair and holds it the while the aphid is suckeddry. Larvae feed for 2-3 weeks and large lar-vae can eat as many as 50 aphids per day.Larvae feed at night and rest near aphidcolonies during the day. The pupa is pear-shaped and fastened to leaves, stems, or

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ground debris. The winter is spent in thepupal stage. Hover flies are most abundantwhen aphid numbers are high.

Adult syr-phid fly

Larva ofa syrphidfly

Pupa of a syr-phid fly

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Long-legged Fly

Family: Dolichopodidae

Characteristics: These are small (1/8 inch),slender flies with long, stilt-like legs. They aremetallic blue, red or green and are often seenresting on leaves in the sunlight. They moverapidly on and among leaves, running andflying quickly. The wings are typically heldout from the body at about a 45 degree angle.

Prey: Adult flies and larvae feed on smallinsects. Long-legged flies are not known to bean important predator of any cotton pest butare often noted in the field.

General Biology: Very little is known aboutthis insect family. Adults are predaceous onother small insects, and the larvae are alsoassumed to be predaceous, although this isnot known for most species. The adult fliescan be very abundant, particularly from mid-season to harvest.

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Long-leggedfly J.

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InsidiousFlower Bug

Orius insidious

Minute Pirate BugOrius tristicolor

Characteristics: The insidious flower bug ismore common in the Southeast and mid-Southwhile the minute pirate bug is the dominantOrius species in the Southwest. Their distribu-tions overlap through central Texas andOklahoma. Adults are very small, 1/8 inchlong, flat and oval shaped. They are black witha white X pattern on the back and have aprominent, forward projecting beak. Adults ofthe minute pirate bug typically have a blackclavus (“V” shaped mark on back) and a faintgray spot on the wing membrane. Insidiousflower bug adults have a white clavus andlight yellow-tan wings. Young nymphs of bothspecies are yellow-orange with a distinctorange scent gland on the abdomen. Oldernymphs are tan to dark brown. Nymphs runquickly and can be confused with thrips andfleahopper or plant bug nymphs.

Prey: Both species are important predators ofmany cotton pests. Adults and nymphs usetheir beaks to pierce and suck the fluids fromthrips, mites, aphids, whiteflies, and eggs andsmall larvae of budworms, bollworms, loopers,and armyworms. Orius are very effective eggpredators. Both species also feed on pollen.

General Biology: Eggs are inserted in leavesand other soft plant tissue and hatch after 3

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days. Nymphs become adults in 12-20 days;adults live 2-3 weeks and females lay about 100eggs. Both species move into cotton early inthe season to feed on thrips and spider mites.Later in the season they are often found in ter-minals and blooms. Insidious flower bugs arecommon in corn silks.

Insidiousflower bugadult

Minutepirate bugadult(arrowpoints toclavus)

Oriusnymph W

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ScymnusLady Beetle

Scymnus loewiiScymnus creperus

Scymnus medionotansScymnus terminatus

Characteristics: Scymnus lady beetles arevery small, dull orange to brown beetles. Onespecies, S. loewii, has a black center lineforming a “V” pattern on the wing covers.Larvae are covered with long, white streamersof wax. These fuzzy, white larvae are some-times confused with mealybugs. Species ofScymnus are found throughout the CottonBelt.

Prey: Adults and larvae feed primarily onaphids, but may also feed on spider mites incotton.

General Biology: Eggs are tiny, barrel-shapedand golden and laid singly in tight spots onthe plant such as at the base of cotton leaveswhere the hairs are dense. Eggs hatch in 3-4days and larvae develop in 14-17 days. Pupaeresemble larvae in that they are covered withwax but unlike larvae do not move. Adultsemerge from pupae after 5-8 days and live 3-6weeks. There are typically 2 or 3 generationsper year in cotton and numbers are greatestwhen aphids are present. The wax coveringmay provide Scymnus larvae some protectionfrom fire ants as they are not attacked by antsas readily as other aphid predators.

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Eggs of Scymnuson leaf

Larva of aScymnus ladybeetle

Scymnuslady beetleadult

Pupa ofScymnuslady beetle

Univ. Florida, Entomology Dept.

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StethorusLady Beetle

Stethorus picipes

Characteristics: The adult is jet black andvery small, about the size of a pinhead andcommonly seen in spider mite colonies. Theadults run rapidly when disturbed. Larvae aredark brown to black and covered with finehairs.

Prey: Both adults and larvae feed on spidermites and their eggs.

General Biology: Stethorus lady beetlesappear in cotton when spider mites are pre-sent. Eggs are laid in spider mite colonies.

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AdultStethoruslady beetle

Larva ofStethorus

J.K

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Fire AntsSolenopsis invicta

Solenopsis geminataSolenopsis xyloni

Solenopsis richteri

Characteristics: The red imported fire ant is areddish-brown to black ant identified by its verypainful sting which results in the formation ofan itching, white pustule. Red imported fire antsare found throughout the southern U.S. fromNorth Carolina to central Texas. Related speciesinclude the black imported fire ant, found innorthern Mississippi and Alabama; the tropicalfire ant, found along the Gulf Coast and northto South Carolina; and the southern fire ant,distributed along the southern U.S. fromCalifornia to North Carolina. All of these relatedspecies can be found in cotton but have oftenbeen displaced by the red imported fire ant.

Prey: Fire ants are voracious predators of boll-worm and budworm eggs and small caterpillars,fleahoppers, boll weevils and other insects. Fireants often search cotton plants during the nightand thus go unobserved. Studies in Texas foundthat a fire ant may take up to 0.3 bollworm orbudworm eggs and 0.1 small worms per day.Fire ants quickly recruit nest mates to overcomelarge caterpillars and other prey. Fire ants arethe only predators of boll weevil larvae and willchew into fallen squares to butcher and carryaway weevil grubs. However, fire ants readilyfeed on aphid honeydew and “farm” aphids bydriving away or killing predators and parasitesthat attack aphids. As a result, large numbers offire ants can contribute to increases in aphidinfestations. Fire ants probably have littleimpact on populations of predatory insects orspiders in cotton, except those feeding onaphids.

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General Biology: Imported fire ants reside inlarge colonies in the soil consisting of 100,000 tomore than 500,000 ants. Colonies may constructlarge mounds, especially after rains. During dryweather, mounds may not be visible. Fire antsmay be more abundant along field margins andin reduced tillage fields where colonies escapecultivation. Fireants are activethroughout theseason.

Fire ants“farming”aphids

Redimportedfire antsattackingpink boll-worm

Redimportedfire anteatingmoth egg W

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Six-spottedThrips

Scolothrips sexmaculatus

Characteristics: Like plant-feeding species,the predatory six-spotted thrips is a tiny (1/16inch), slender straw colored insect with shortantennae. It is named for the six black spotson its wings which are held folded above theabdomen. Larvae lack wings and are white toyellow and cigar-shaped. The six-spottedthrips is commonly found in spider mitecolonies.

Prey: Adults and larvae feed on plant-feedingspider mites and their eggs. Six-spotted thripsare well adapted to penetrating the silk web-bing made by plant-feeding mites and havebeen credited with reducing spider mite out-breaks in Arkansas in some years. In labora-tory studies, females killed more than 1,700mite eggs during their 45-day lifespan.

General Biology: Eggs are inserted into leaftissue and hatch in about 7 days. Larvae feedfor about 5-6 days and then enter the pupalstage in the mite colony. Development fromegg to adult requires about 2 weeks.

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Adult six-spottedthrips M

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PredatoryMites

Galendromus (=Metaseiulus) occidentalisAmblyseius californicus

Characteristics: Predatory mites are largerthan plant-feeding mites and are pear-shaped.They are reddish-tan in color, have long legsand run quickly when disturbed. The twospecies listed above are found in Californiabut their distribution and that of other preda-tory mite species in cotton are not wellknown.

Prey: Predatory mites feed on plant feedingspider mites and their eggs.

General Biology: The western predatory mite,G. occidentalis and A. californicus are com-mon in vineyards and alfalfa in California.Numbers of predatory mites in cotton oftendo not increase early enough to control spidermites. Releasing predatory mites has shownpromise for controlling spider mites inCalifornia.

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Predatorymite feedingon two-spot-ted spidermite J.

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Archytasmarmoratus

Family: Tachinidae

Characteristics: Archytas marmoratus is alarge, stocky fly about 1/2 inch long withlong black bristles on its abdomen and tho-rax. The silvery-white “face” is characteristicof this species which is found throughout thesouthern U.S.

Hosts: A. marmoratus is an important para-site of the larval stage of the bollworm, bud-worm, black cutworm, fall armyworm andrelated moth species in cotton, alfalfa andcorn. Medium to large larvae, 4-5th instars,are most commonly parasitized.

General Biology: The adult fly deposits mag-gots, rather than eggs, on cotton leaves wherebollworms and budworms are feeding. Thebluish-green maggots can lie in wait severaldays and quickly attach themselves to boll-worms or other caterpillars that crawl withinreach. The maggot penetrates thebollworm/budworm larva but does not beginto eat or develop. Parasitized bollworms con-tinue to feed and develop normally. Once thebollworm or budworm has entered the soiland pupated, the fly maggot begins to con-sume the pupa. The maggot feeds for 6-10days and then pupates. A single adult flyemerges about 8-10 days after the hostpupates. A female can produce 2,000 or moremaggots during her lifespan of 50-70 days.Winter is spent in the adult stage.

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AdultArchytasmarmora-tus

Face offemale A.marmora-tus show-ing silver-whiteface

Scanningelectronmicrographof larva(planidium)of Archytaswaiting on aleaf to para-sitize passingcaterpillar

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TachinidFlies

Lespesia archippivoraEucelatoria bryani

Characteristics: The large tachinid (about 1/2inch long) with a silvery-white face isArchytas marmoratus and is discussed indetail on the previous page. Some otherimportant tachinid species belong to the gen-era Lespesia and Eucelatoria. Lespesia is asmall (4-8 mm) gray fly which runs and fliesquickly and is found throughout the CottonBelt. Eucelatoria bryani is an active, grayishblack fly about 1/4 inch long with a reddishtinge at the tip of its abdomen and is foundfrom Mississippi west to Arizona. A relatedspecies, E. armigera is found in California andArizona.

Hosts: Lespesia archippivora parasitizes manydifferent kinds of caterpillars, including boll-worm, fall armyworm, beet armyworm, cab-bage looper and black cutworm. E. bryani isa common parasitoid of bollworm, budwormand fall armyworm larvae.

General Biology: While some tachinid flieslay their eggs on leaves, the femaleEucelatoria alights on a bollworm or bud-worm larva and using a sharp barb on herabdomen, rips open a hole in the caterpillar’sskin. She then deposits up to 20 maggots intothe caterpillar. The maggots feed inside thelarva for 4-5 days. Once the bollworm or bud-worm has completed feeding and tunneledinto the soil in preparation for pupating, themaggots emerge from the now dead caterpil-lar and pupate. The adult flies emerge about

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10 days later and live for several weeks.Adults overwinter.

Lespesia females land on the caterpillarand deposit their eggs on the caterpillar’sbody. The fly eggs hatch in about 20 minutesand the grubs tunnel into the armyworm. Thegrubs feed internally for 10-16 days, finallycausing the death of the armyworm. Maturegrubs emerge from the dead host and pupate.Adults flies live for several weeks and produceabout 100-200 eggs.

An adulttachinid fly U

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Macrocentrusgrandii

Family: Braconidae

Characteristics: Macrocentrus grandii is asmall wasp, about 1/4 inch long, with longantennae and a very long (1/4 inch) “stinger”or ovipositor. The head is dark while the tho-rax and legs are red-orange. The abdomen islighter with several black bands.

Hosts: M. grandii is an important parasitoidof European corn borer larvae in cotton andother crops.

General Biology: Adult female wasps stingEuropean corn borer larvae and deposit a sin-gle egg inside the corn borer. The egg dividesand yields about 25 or more grubs which feedinternally. Once the grubs are full grown, theyemerge from the now dead corn borer andspin white cocoons near the remains of thehost. About 20 adult wasps will emerge fromeach parasitized European corn borer larva.Corn borer larvae are not killed until afterthey have completed feeding, thus parasitismhelps limit the following generation. Studiesin North Carolina found M. grandii para-sitized about 50 percent of the European cornborer larvae in cotton.

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AdultMacrocentrusgrandii M

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MicroplitiscroceipesFamily: Braconidae

Characteristics: Adults are large dark brownto black wasps about 1/3 inch long. Theabdomen and legs are yellow to red and thewings are dark. The cocoons are off whiteto yellowish and smooth with long ridges.M. croceipes is found throughout the CottonBelt except it is not reported fromCalifornia.

Hosts: In some areas, M. croceipes is one ofthe most common parasites of bollworm lar-vae in cotton. As many as 50 percent ofbollworm larvae may be parasitized by thiswasp. All stages of larvae are attacked but3rd and 4th instars are preferred. Budwormlarvae are also parasitized. M. croceipes par-asitizes bollworms infesting alfalfa,sorghum, tomato, wild hosts and corn inthe whorl stage but not in the ear stage.

General Biology: The adult female stingsthe bollworm larva and deposits her eggsinside the caterpillar. Third instar larvae aremost commonly parasitized. Larger larvaeoften drive off the parasite before it cansting. The wasp’s egg hatches into a grubwhich feeds inside the bollworm for about 8days. The parasitized bollworm soon stopsfeeding. Once full grown, the wasp grubbores out of the dead bollworm and spins awhite cocoon. The adult wasp emerges fromthe cocoon in about a week. Developmentfrom egg to adult requires about 15 days at86°F. There are 3 or 4 generations per year

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and the wasps overwinter in the soil asmature larvae (prepupae) inside cocoons.

AdultMicroplitiscroceipesandcocoonnear hostlarva

Larva ofM. cro-ceipesemergingfrom par-asitizedcaterpil-lar

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CardiochilesnigricepsFamily: Braconidae

Characteristics: The adult wasps are about1/4 inch long with long antennae and verydark wings. The head and thorax are blackwhile the abdomen and middle and hind legsare red. C. nigriceps is sometimes called the“red-tailed” wasp because of the redabdomen. The ovipositor (stinger) is shortand black and often not visible. This parasiteis widely distributed across the southeasternCotton Belt west to Oklahoma and Texas.These brightly colored wasps may be seenhovering about cotton plants in search ofcaterpillars to parasitize. They can be verycommon in some fields, averaging 1-2 waspsper meter (yard) of row.

Hosts: C. nigriceps is one of the most impor-tant parasitoids of the budworm. It can onlysuccessfully parasitize budworm larvae and arelated species, H. subflexa, which is not acotton pest. Wasps will sting bollworm larvaebut the parasite eggs do not develop and thebollworm survives. Also, beet armywormlarvae are occasionally parasitized by thiswasp. All sizes of budworm larvae areattacked but late second and third instars arepreferred.

General Biology: Adult female wasps stingbudworm larvae and deposit eggs internally.Eggs hatch into grubs which feed internallyfor about 2 weeks. Small budworm larvaecontinue to grow once parasitized while thosein the 4-5 instar do not. Once full grown, theparasitoid grub emerges from the dead bud-

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worm larva and spins a cocoon in the soil.The adult wasp emerges in about 2 weeks andlives for about 2 weeks. There are about 3 or4 generations per year and wasps overwinteras pupae in the soil.

AdultCardiochilesnigriceps W

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Chelonusinsularis

Family: Braconidae

Characteristics: This small (1/8 inch) robustwasp has a small white patch on each side ofthe front of the abdomen C. insularis is foundthroughout the Cotton Belt.

Hosts: C. insularis parasitizes eggs of thebollworm, beet armyworm, fall armywormand several other armyworm species.

General Biology: The female places her egginside the bollworm or armyworm larva whilethe larva is still inside the egg. The larvahatches and develops normally for severaldays but soon appears shrunken and dry asthe Chelonus larva feeds internally. The para-sitized host larva then spins a fine-meshed,yellow silk cocoon, called the “death-cell”,around itself. About 2 days later the army-worm larva dies. A day later, the full grownChelonus larva emerges from the shriveledbody of the armyworm and pupates nearby.

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AdultChelonusstinging(parasitiz-ing) amoth egg W

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Braconmellitor

Family: Braconidae

Characteristics: The adult B. mellitor is abrownish-orange wasp about 1/16-3/16 inchlong. The dark eyes, antennae and legs andthe dusky areas on the wings give it a blackappearance. The abdomen is broad and thefemale has a black ovipositor (stinger) almostas long as her body. Bracon mellitor is nativeto the U.S. and found throughout the CottonBelt and northern Mexico. Bracon hebetor is arelated species.

Hosts: B. mellitor parasitizes boll weevilgrubs. It is often the most common insectparasite of the boll weevil. It also parasitizesother weevil species and some caterpillars,including the pink bollworm. Adult waspsfeed on nectar produced at the base of cottonsquares.

General Biology: The female Bracon mellitorsearches cotton squares and bolls and probesthe fruit with her ovipositor to detect weevilgrubs inside. Once a grub is located, thefemale drills through the fruit and paralyzesthe grub by stinging it. A single egg is thenplaced on the grub or nearby in the grub’scavity. The egg hatches in a day and the tinyparasite larva pierces the paralyzed weevilgrub and feeds on its body fluids. After 4-5days, the parasite larva is full grown and itspins a white silk cocoon in which it pupatesinside the weevil’s cell. The adult waspemerges from the cocoon in about 3-6 daysand escapes from the weevil’s cell by chewingthrough the square or boll. Female wasps live

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about 3 weeks and produce about 160 eggseach. Winter is spent as a mature larva (pre-pupa) inside the cocoon.

Adult Braconmellitor J.

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HyposoterParasite

Family: Ichneumonidae

Characteristics: These are slender, elongatewasps (1/4 inch long), with mostly orangeabdomens that are flattened on the sides. Theabdomen is narrowly attached to the thorax.Cocoons are attached to leaves, are shapedlike short fat sausages, and are typicallybanded in silver/grey and black. AlthoughHyposoter spp. are reported throughout theCotton Belt, they are more prevalent fromTexas westward.

Hosts: Hyposoter wasps attack a wide rangeof caterpillars, including bollworms, bud-worms and armyworms.

General Biology: The adult female attackssmall caterpillars, laying a single egg inside.The parasite grub emerges from the larvaafter 8-10 days and spins a cocoon on theleaf. The adult parasite emerges from thecocoon 5-7 days later.

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Hyposotercocoonnearremains ofparasitizedcaterpillar

Armywormtorn apart,revealingHyposoterlarva

Adultandcocoon

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Cotesiamarginiventris

Family: Braconidae

Characteristics: Cotesia marginiventris is asmall wasp, about 1/8 inch long, slender andblack. The white cocoons, containing Cotesiapupae, are commonly seen on cotton leaves.The cocoons are solitary and resemble afuzzy grain of rice attached to the leaf.

Hosts: Cotesia parasitizes larvae of boll-worms, budworms, loopers and beet, fall andsouthern armyworms in cotton and other fieldcrops. This parasite is particularly effectiveagainst beet armyworms.

General Biology: The adult wasp lays her egginside the host caterpillar. The egg hatches in1-2 days and the parasite grub feeds insidethe caterpillar for about 6 days. The fullgrown grub then bores out of the caterpillar,causing it to die, and spins a white cocoonaround itself. The adult wasp emerges fromthe cocoon about 4-5 days later. A singlefemale can parasitize (kill) 200-300 hostcaterpillars during its 10- to 14-day life. Theremay be 4 to 6 generations per year.

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Adult Cotesiamarginiventrisparasitizingbeet army-worm larva

Cocoon ofCotesia mar-giniventris onleaf

Cocoons ofCotesia onleaf adjacentto beet army-worm damage

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Catolaccusgrandis

Family: Pteromalidae

Characteristics: C. grandis is a medium sizedwasp ( 3/16 inch ) with large eyes, a broadthorax, short antennae and an abdomenwhich tapers to a point. It is native to Mexicoand although released into the U.S., it has notestablished due to its inability to survive thewinter. As a result, C. grandis is not naturallypresent in the U.S. Catolaccus hunteri is arelated species native to the U.S.

Hosts: C. grandis parasitizes larvae (grubs) ofthe boll weevil. Grubs in the third instar aremost commonly parasitized. Also, more grubsin squares on the plant are attacked than aregrubs in squares on the ground.

General Biology: The wasp searches squares,detecting weevil grubs inside. Wasps learnwhere squares have the most grubs and con-centrate searching and stinging either on theplant or on the soil (fallen squares). Thefemale wasp drills through the cotton squareand paralyzes the boll weevil grub by stingingit. She then places an egg on the grub. Theegg hatches and the parasite larva feeds exter-nally on the paralyzed weevil grub for about6 days. Once full grown, the larva pupatesinside the cotton square or boll near the deadboll weevil grub. The adult wasp emergesabout 5 days later. Development from egg toadult requires about 13 days at a temperatureof 86°F. In lab studies, adult wasps livedabout 45 days and each female parasitized200-300 weevil grubs. Females also pierceweevil grubs and feed on their blood. Field

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studies have shown releasing laboratory-reared C. grandis early in the season holdspromise for controlling boll weevil. However,costs for rearing this parasite must be reducedto be economical. Research is ongoing to findinexpensive methods of mass rearing C. gran-dis for annual release in cotton for boll weevilcontrol.

AdultCatolaccusgrandis

AdultCatolaccusstinging bollweevil in rear-ing cell

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MeteorusParasite

Braconidae: Meteorus species

Characteristics: The adult is a golden brown,slender wasp about 1/4 inch long. Femaleshave a long stinger (ovipositor) projectingbackward from the abdomen about the lengthof the abdomen. Cocoons are brown, about1/3 inch long, shaped like a football and aresuspended from the leaf on a filament.

Hosts: Meteorus attacks a wide range of cater-pillars, including beet, fall and southernarmyworms in a variety of crops and wildplants.

General Biology: Meteorus females lay eggsin nearly all larval stages of their hosts,although small larvae are most frequentlyparasitized. After feeding internally for 10-12days, the parasite grub emerges from the hostand spins its football-shaped cocoon whilesuspended from the leaf on a silken thread.The adult lives 3-6 weeks and is capable ofparasitizing 150-300 hosts during its lifetime.There appear to be 3 or 4 generations peryear.

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AdultMeteorusparasite J.

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Lysiphlebustestaceipes

Family: Braconidae

Characteristics: Lysiphlebus testaceipes is ashiny, slender black wasp about the size of acotton aphid. Wasps can often be seen inaphid colonies as they sting (parasitize)aphids. More commonly, the parasitizedaphid mummies are seen, evidence this para-site is active in the field. Aphid mummies aredead swollen aphids stuck to leaves. Themummies are tan to gold and contain a devel-oping wasp or have a hole cut in the topthrough which the wasp emerged.

Hosts: L. testaceipes attacks the cotton aphidin cotton and other aphid pests such asgreenbugs in wheat.

General Biology: The female pierces (stings)the cotton aphid and deposits an egg inside.The egg hatches in about 2 days and the par-asitoid grub feeds internally on the livingaphid. The grub is full grown in about a weekat which time the aphid takes on a swollen,tan appearance and dies. The parasitizedaphid is termed a “mummy” and is attachedto the leaf. The grub enters the pupal stageand about 4-5 days later, the adult waspemerges through a circular hole cut towardsthe back of the aphid mummy. Developmentfrom egg to adult requires about 2 weeks. Asingle female can parasitize about 100 aphidsduring her 4- to 5-day life span.

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L. testa-ceipesadult

Aphid mummyshowing exithole cut byemerging adultwasp

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CA

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LooperParasite

Encyrtidae: Copidosoma species

Characteristics: This tiny (1/16 inch) shinyblack wasp resembles a small fly. Loopers par-asitized by Copidosoma are most easily recog-nized after they spin their pupation cell on theunderside of leaves. Unparasitized loopersform a green pupa that later darkens tobrown. Parasitized loopers, in contrast, fail topupate, but instead elongate, causing the headto fold into a hook shape under the body. Thelarva takes on a cream or light tan color, andappears to be made of styrofoam. Each of the“foam” cells in the caterpillar’s body is actual-ly a developing wasp. These parasites arefound throughout the Cotton Belt.

Hosts: These wasps attack loopers, especiallysoybean loopers.

General Biology: Adult wasps sting loopereggs, laying a single egg in the host egg. Afterthe looper hatches, the nucleus in the waspegg divides repeatedly and each nucleibecomes a wasp larva. Up to 2,000 wasps candevelop in a single host looper. The para-sitized looper requires a bit longer to developthan an unparasitized looper and eats up to50 percent more foliage than an unparasitizedlooper. Development from egg to adultrequires about 17-27 days and there are 2 or 3generations per year. A single female is capa-ble of parasitizing 10-30 loopers. Late in theseason, these parasites can practically elimi-nate a soybean looper population in a singlegeneration.

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A looperfilled withhundreds ofCopidosomapupae. Thesilk cocoonspun by thedying looperhas beenremoved

W. Sterling

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Stink Bug EggParasites

Family Scelionidae:Telenomus speciesTrissolcus species

Characteristics: These are tiny (1/20-2/20inch), shiny black wasps with antennae thatare elbowed downward. The wings have verylittle venation. The shape of the body variesfrom slender and somewhat flattened top tobottom, to short and very stout. These para-sites are found throughout the Cotton Belt.

Hosts: These wasps parasitize eggs of differ-ent stink bug species, including predaceousstink bugs in some cases. The species of stinkbug attacked depends on the parasite species.Some attack many species of stink bugs whileothers parasitize only a few species. Trissolcusbasalis is an important parasite of the south-ern green stink bug which can be a pest ofcotton.

General Biology: The parasite females laytheir eggs in the eggs of the stink bug, usual-ly only one parasite egg per host egg. A singlewasp develops in each egg. Parasitized stinkbug eggs turn black within a few days of par-asitism. The adult parasite emerges from theegg about 8-20 days after the parasite egg isplaced in the stink bug egg. Adult parasiteslive about 2-6 weeks and can parasitize from30 to over 100 stink bug eggs in a lifetime.

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AdultTrissolcusbasalisparasitiz-ing eggsof thesoutherngreenstink bug

Anotherspecies ofstink bugegg para-site. Noteelbowedantennae

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WhiteflyParasites

Family: Aphelinidae: Eretmocerus speciesEncarsia species

Characteristics: Although these wasps arevery tiny, about 1/25 inch long (1 mm), theyare among the most important natural ene-mies of whiteflies. Because of their small size,adults are rarely seen. However, whiteflynymphs parasitized by these wasps can beidentified by the circular hole cut in the topof the nymph through which the adult waspescaped. Whitefly nymphs parasitized bysome Encarsia species turn black while thoseparasitized by Eretmocerus do not. BothEretmocerus and Encarsia are distributedthroughout the Cotton Belt but the range ofindividual species is variable and oftenunknown. Eretmocerus spp. near californicusis an important native species in theSouthwest. Encarsia pergandiella is an impor-tant native species while E. formosa is intro-duced into the U.S.

Hosts: These wasps parasitize nymphs ofwhiteflies. Adult wasps also act as predatorsas they sting whitefly nymphs, creating a holeand feeding on the body fluids that flow out.

General Biology: Adult wasps search forwhitefly nymphs and lay an egg in the nymph(Encarsia) or under the nymph (Eretmocerus).The wasp larva feeds internally, killing thewhitefly nymph. The parasite larva thenpupates and later the adult wasp escapesthrough a hole cut in the top of the whiteflynymph. In contrast, whitefly pupae fromwhich an adult whitefly emerged have a “T”

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shaped slit in the pupal skin. Nymphs para-sitized by Eretmocerus are a dark amber colorcompared to the lighter colored healthynymphs. Development from egg to adultrequires 18-25 days for Eretmocerus and some-what less for Encarsia. A single female waspparasitizes 40-50 whitefly nymphs and killsmany other nymphs by direct feeding.

Eretmocerusadult sting-ing (para-sitizing) awhitefly

Encarsiaformosaadult

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MymaridWasps

Family: Mymaridae: Anaphes iole

Characteristics: These very tiny wasps, lessthan 0.04 inch (0.6mm), have very slenderhind wings. They may be captured in yellowpan traps or with sweep nets made of canvasor reared from lygus bug eggs collected fromcotton and alfalfa. Parasitized lygus eggs areblack. Anaphes iole is known to occur inLouisiana, California and Arizona and isprobably present throughout most of CottonBelt.

Hosts: Anaphes iole is an important parasiteof eggs of the lygus bug, Lygus hesperus andthe tarnished plant bug, L. lineolaris. A. iolealso parasitizes eggs of some species ofdamsel bugs (p.56) in beans. However, stud-ies in the Southwest showed A. iole did notattack damsel bug eggs in cotton.

General Biology: The adult parasite depositsher egg into the lygus eggs which are insertedinto plant tissue. The wasp egg hatches into agrub which consumes the contents of thelygus egg and pupates. A single adult wasplater emerges from the lygus egg.Development from egg to adult requires about15 days.

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Anaphes iole,a parasite oflygus bugeggs M

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TrichogrammaWasps

Trichogramma pretiosumTrichogramma exiguumTrichogramma minutum

Trichogrammatoidea bactrae

Characteristics: Trichogramma are extremelytiny wasps which develop inside the eggs ofmoths and butterflies. Adults are not seen inthe field because of their small size. However,eggs of bollworms and budworms which areblack indicate the presence of Trichogrammawasps. A powerful hand lens or microscope isnecessary to clearly see these minute para-sites. Adults are yellow and brown and thewings have only a few veins. T. pretiosum isfound throughout most of the Cotton Belt. T.exiguum has been reported from Alabama,Arkansas and Texas and may be present inother areas also. Several species ofTrichogramma are reared in commercial insec-taries and promoted for control of bollwormsand budworms. T. bactrae was introducedfrom Australia and is reared and sold forrelease against the pink bollworm.Identification of the species requires highmagnification and specialized training.Bollworm/budworm eggs also turn blackwhen parasitized by another tiny waspnamed Telenomus heliothidis (Scelionidae).Telenomus are uniformly shiny black.

Hosts: Trichogramma parasitize eggs of boll-worms, budworms, loopers and other cater-pillar pests. Some species also parasitize eggsof green lacewings. Current studies indicateTrichogramma rarely parasitize beet army

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Trichogramma wasp parasitizing a moth egg

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TrichogrammaWasps

(Continued)

worm or fall armyworm eggs which are cov-ered by scales left by the female moth.

General Biology: The adult female places oneor more eggs inside the host egg using her“stinger” (ovipositor). The egg(s) hatch in aday and the wasp larvae feed inside the eggfor about 3 days and then pupate inside thehost egg. At this time, dark deposits on theinside of the host egg cause it to turn black.After 4-5 days, the adult wasp cuts a hole inthe side of the host egg and emerges.Development from egg to adult requires 8-10days. Adults live about 10 days.Trichogramma will parasitize all stages ofbollworm/ budworm eggs except those withina few hours of hatch (black-head stage).Adults are active throughout the season.Immature stages overwinter in host eggs andadults are active during warmer days of thewinter in southern climates.

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Bollworm eggparasitized byTrichogramma

Unparasitizedbollworm egg

J. R

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J. R

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Cotton AphidFungus

Neozygites fresenii

Characteristics: Cotton aphids recently killedby this fungus are covered with a velvetywhite or light gray growth. Close examinationwill show the dead aphids are still attached tothe leaf with their mouthparts. Soon, otherfungi begin to appear on the dead aphid, giv-ing it a fuzzy olive-brown appearance.Fungus-killed aphids should not be confusedwith aphid “skins” which are white andshriveled or with parasitized aphids (p. 107).N. fresenii is found from Georgia to centralTexas.

Hosts: N. fresenii is the most important natur-al enemy of the cotton aphid in the mid-South and Southeast when aphid populationsreach high densities. Widespread outbreaks ofthis fungus, called epizootics, often occurwhen aphid numbers are high and can elimi-nate aphid infestations in 7-10 days in someareas. Epizootics can occur during relativelydry weather. This fungus only attacks aphids.

General Biology: Cotton aphids infected withN. fresenii produce fungal spores which landon leaves. The sticky spores attach to the legsof aphids as they walk across leaves. Oncethe spores contact an aphid, they germinateand penetrate the aphid’s body. The fungusgrows internally and the aphid dies in 3-4days. The fungus then grows outside the deadaphid and shoots tiny spores which are car-ried on the wind. A single aphid can release3,000 spores and up to 60,000 spores percubic meter of air have been reported at night

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in cotton fields during epizootics. The funguscompletes its life cycle in 3 days, allowingrapid increase in the number of infectedaphids. Cotton aphid infestations often crash7-10 days after fuzzy aphids killed by N. fre-senii are found in a field. Careful scouting todetect the fungus earlier can be used to pre-dict epizootics and possibly avoid the need foraphicides. Resting spores survive in the soil.Winged aphids, infected yet still alive, canalso carry the fungus.

Cottonaphids killedby Neozygitesfungus onunderside ofcotton leaf

Neozygitesspores andcotton aphidkilled byNeozygitesfungus

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NPVDisease

Nuclear polyhedrosis virus

Characteristics: Insects killed by NPV are dis-colored and limp. They often hang fromleaves attached only by one or two legs.Infected caterpillars are filled with a cloudyliquid inside and are easily broken openwhen handled. NPVs, also called baculovirus-es, are found nearly everywhere. Differentstrains or “species” of virus occur and eachtends to attack only a limited number ofcaterpillar species.

Hosts: NPVs infect more than 400 insectspecies. Caterpillars of moths and butterfliesare commonly infected. In cotton, cabbageloopers are often attacked by NPV while beetarmyworms, bollworms and budworms areless commonly infected.

General Biology: The liquid released frominsects killed by NPV contains millions ofvirus particles which fall onto leaves. Othercaterpillars ingest the virus particles whilefeeding on contaminated leaves and becomeinfected. Virus particles can also enterthrough natural openings in the caterpillar, orbe carried on the stinger (ovipositor) of a par-asitic wasp. Two to five days after ingestingthe virus, caterpillars become sluggish andeat less. Death follows in 5-12 days. Shortlybefore dying, the caterpillar may climb to thetop of the plant and hang by its prolegs. Theinsect’s body wall is easily ruptured, therebyreleasing liquid and virus particles ontoleaves. Other caterpillars contact the virusand the cycle is repeated.

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Bollworm killed byNPV W

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Beauveria andother Fungi

Beauveria bassianaErynia species

Nomuraea rileyi

Characteristics: Insects killed by Beauveriabecome covered with a white, thick mass offungal growth. The infected insect becomesstiff and if broken apart is found to be filledwith a solid, fungal mass. Beauveria bassianais found throughout the U.S. and is also for-mulated as an insecticide.

Erynia and Nomuraea are other fungal dis-eases of insects.

Hosts: B. bassiana attacks many differentspecies of beetles, moth caterpillars and truebugs. In cotton, bollworms, boll weevils andand a variety of other pest and beneficialinsects are sometimes infected with this dis-ease. Nomuraea and Erynia attack caterpil-lars.

General Biology: Spores (conidia) of B.bassiana and other fungi occur in the soil andare released from infected insects. Spores thatcontact the insect germinate and growthrough the body wall or enter the insect’sbody through natural openings. Spores whichare eaten germinate on the insect’s mouthparts or in the digestive tract and grow intothe insect’s body. The insect dies in a fewdays as its body is filled with fungal growth.The fungus then grows externally over theinsect’s body and releases spores to infectother insects.

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Caterpillar killedby Beauveria fun-gus

Caterpillarkilled byEryniafungus

Soybeanlooper killedby fungusNomuraearileyi

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NOTES

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NOTES

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NOTES

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NOTES

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NOTES

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NOTES

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TO ORDER

Please copy and fill out this form and mailalong with your payment to:

Publication and Supply DistributionTexas Cooperative ExtensionP.O. Box 1209 Bryan, TX 77806-1209

Please send me ____ copies of Field Guide to Predators, Parasites andPathogens Attacking Insect and MitePests of Cotton, B-6046 at $5.00 percopy, which includes postage and han-dling.

Make checks or purchase orders payableto: Texas Cooperative Extension Account#233205

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Sources of entomological suppliesA hand lens is very helpful in identifying the many small

predators and parasites described in this field guide. The follow-ing companies sell hand lenses, nets and other supplies andbooks for collecting, observing, and identifying insects. This list-ing is not exhaustive, and is for information purposes only. Itshould not be construed as an endorsement of the listed compa-nies.

BioQuip Products Carolina BiologicalGardena CA Burlington NC

(310) 324-0620 (800) 334-5551

Forestry Suppliers Ward’s BiologyJackson MS Rochester NY

(800) 647-5368 (800) 962-2660

Gempler’sMt. Horeb, WI(800) 382-8473

The information given herein is for educationalpurposes only. Reference to commercial prod-ucts or trade names is made with the under-

standing that no discrimination is intended andno endorsement by the Cooperative Extension

Service is implied.

Issued in furtherance of Cooperative Extension Work inAgriculture and Home Economics, Acts of Congress of May 8,1914, as amended, and June 30, 1914 in cooperation with theUnited States Department of Agriculture, Edward G. Smith,Director, Texas Cooperative Extension, The Texas A&MUniversity System.

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Extension publications can be found on the Web at: http://tcebookstore.org

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