An unusually large aggregation of the western conifer seed bug, Leptoglossus occidentalis (Hemiptera: Coreidae), in a man-made structure

2 Pages·1994·1.1 MB·English

by  S E Blatt

J.Entomol.Soc.Brit.Columbia91,December, 1994 71
An
unusually large aggregation ofthe
western conifer seed bug,Leptoglossus occidentalis
(Hemiptera: Coreidae), in a man-made structure
BLATT
S. E.
DEPARTMENTOFBIOLOGICALSCIENCES,CENTREFORPESTMANAGEMENT
SIMONERASERUNIVERSITY,BURNABY,BC,V5A1S6 CANADA
ABSTRACT
An overwintering aggregation ofmore than 2000Leptoglossus occidentalis is reported in a
manufacturingplantinthesoutherninteriorofBritishColumbia.Suchaggregationsmaybeme-
diatedbypheromones.Rangeextensionmayhaveoccurredthroughinadvertenttransportofag-
gregationsofoverwinteringadults.
DISCUSSION
The western conifer seed bug, Leptoglossus occidentalis Heidemann, is a serious pest of
coniferseedproducrion (Koerber 1963), particularly onPinus spp. (Connelly andSchowalter
1991).Duringthe fall adults, like othercoreids, seek sheltered overwintering sites. Whenhu-
man habitation interfaces with forests, these sites can include garages, birds' nests (Hussey
1953) andhouses (T.W. Koerber,Entomological Services Inc., Berkeley, California, personal
communication).L.occidentalishasrecentiyextendedtheeasternlimitsofitsrangeandhasbe-
comeacommonhouseholdpestinMichigan(Gall 1992),Ontario(Marshall 1991;McPherson
etal. 1990),WisconsinandMinnesota(KatovichandKulman 1987).Numbersofinsectsfound
inoronthehomesvariedfromlessthanadozentoroughlyahundred individuals.
In October 1993, Richard Prebble, Managerofthe Imperial Chemical Industries (ICI) Ex-
plosivesPlantinTappen, BC, 78 kmeastofKamloops, reported an infestationofL. occiden-
talisinandaroundthemanufacturingplant.Oninspectingthe site,IfoundlargenumbersofL.
occidentaliscongregatedarounddoorjambs,windowsandincrackswithintheconcretewalls.
Hundredsofbugswereaggregatedaroundheatingexhaustports.Icollected 1065livebugs(608
malesand457females)andestimatedthattherewereatleast 1000moredeadonthefloors,win-
dowsillsandinthedoorjambs; aresultofchemicalcontrolby theplantstaff. Severalworkers
indicatedthattheinfestationwas'manageable' comparedwithwhatithadbeenjusttwoweeks
before. Forthe pastthree years, similarinfestationshave been observed atthis plant; they re-
portedlylastforroughlythreeweeksandthen'disappear'.Anaerialphotographobtainedfrom
theBCMinistryofForestsshowedthatL.occidentalismusthaveflownaconsiderabledistance
m
toreachtheaggregationsite.Theplantislocatedinameadow,atleast300 fromforestedges
m m
tothenorthandwest,900 fromapatchofconiferstotheeastand750 fromasmallpatch
ofconiferstothesouth.
SmallaggregationsofLeptoglossuscorculus(Say)havebeenobservedinthesouthernUSA
(J.C.Nord,USDAForestService,Athens,Georgia,personalcommunication)andoverwinter-
ingaggregationsofotherHemipteraalsooccur.Schowalter(1986)documentedanaggregation
ofca. 8,000boxelderbugs,Boisearubrolineata(Barber),inwesternOregon.Theaggregation
wasfound500-1,000mawayfromfeedinghosts. Aggregationsof>6,000swallowbugs, Oe-
ciacusvicariusHorvath,havebeenreportedinWashington(Zack 1990). Chinchbugs,Blissus
leucopterusleucopterus (Say), alsoaggregate tooverwinterin groupsoftypically < 200 indi-
viduals (Negron and Riley 1991). In all instances, pheromonal attraction was suggested as a
causal factorofaggregations. Ithas beenhypothesized that extension in the range ofL. occi-
dentalis has occurred through the inadvertent transport by mankind ofaggregations ofbugs
overwintering on or in transported goods (L.M. Humble, Canadian Forest Service, Pacific
ForestryCentre,Victoria,BC,personalcommunication).
. .
72 J.Entomol.Soc.Brit.Columbia91,December, 1994
ACKNOWLEDGMENTS
I thank Dr. J.H. Borden for review and R. Prebble for allowing me to collectbugs on ICI
premises.FundingforthisworkwasprovidedbytheCanadianForestServiceandNaturalSci-
encesandEngineeringResearchCouncilofCanada.
REFERENCES
Connelly,A.E.andT.D.Schowalter1991.SeedlossestofeedingbyLeptoglossusoccidentalis(Heteroptera:Coreidae)
duringtwoperiodsofsecondyearconedevelopmentinWesternWhitePine.J.Econ.Entomol.83:1485-1486.
Gall,W.K. 1992.FurthereasternrangeextensionandhostrecordsforLeptoglossusoccidentalis(Heteroptera:Corei-
dae):well-documenteddispersalofahouseholdnuisance.GreatLakesEntomol.25:159-171
Hussey,R.F. 1953.ConcerningsomeNorthAmericanCoreidae(Hemiptera).Bull.BrooklynEntomol.Soc.48:29-34.
Katovich,S.A.andH.M.Kulman1987.LeptoglossuscorculusandLeptoglossusoccidentalis(Hemiptera:Coreidae)at-
tackingredpine,Pinusresinosa,conesinWisconsinandMinnesota.GreatLakesEntomol.20:119-120.
Koerber,T.W. 1963.Leptoglossusoccidentalis(Hemiptera: Coreidae) anewlydiscoveredpestofconiferous seed.
Ann.Entomol.Soc.Amer.56:229-234.
Marshall,S.A. 1991.AnewOntariorecordofaseedeatingbug(Hemiptera:Coreidae)andotherexamplesoftherole
ofregionalinsectcollectionsintrackingchangestoOntario'sfauna.Proc.Entomol.Soc.On. 122:109-111
McPherson,J.E.,R.J.Packauskas,S.J.TaylorandM.F.O'Brien 1990.EasternrangeextensionofLeptoglossusocci-
dentaliswithakeytoLeptoglossusspeciesofAmericanorthofMexico(Heteroptera:Coreidae).GreatLakesEn-
tomol.23:99-104.
Negron,J.F.andT.J.Riley 1991.Seasonalmigratonandoverwinteringofthechinchbug(Hemiptera: Lygaeidae)in
Louisiana.J.Econ.Entomol.84:1681-1685.
Zack,R.S. 1990.Swallowbug(Heteroptera:Cimicidae)inWashingtonwithanunusualoverwinteringsite.PanPac.
Entomol.66:251-252.