2016 Virginia Tech 3101-1527 (ENTO-194NP)

EarwigsinVirginia

EricDay,DepartmentofEntomology,VirginiaTech

DESCRIPTION:Earwigscanbeup to1and1/4 inches(25.4 -31.8mm).MostareRed-browntoblack incolor.Adultearwigsare flattened insects,upto1and1/4 inches in length,and lightred-browntoblack.Some species arewingless but others have a pair of leathery forewings covering a few segments of theabdomenandthemembranoushindwings,whichhavethetipsprotruding.Theforceps-likeappendagesatthe end of the abdomen are strongly curved in themale. The female's appendages are smaller and lesscurved. The forceps are used primarily for defense and duringcourtship and cannot harm people. Earwigs are primarilyscavengers on dead insects and rotted plant materials. Somespeciesarepredators.Onlyafewofthewingedspeciesaregoodfliers. They are often transported great distances in plantmaterials and occasionally in other freight. The most commonearwig in Virginia is the European earwig,Forficula auricularia.Dermaptera:ForficulidaeHABITAT:Mostcommonlyassociatedwithmulchand leaf litter,theyprefermoistlocationswithhighamountsoforganicmatter;ironicallyit’softenexactlythesameaswhatisrecommendedforgoodplantgrowth.Theyareactiveatnightandsomespeciesareattracted to lights in largenumbers.During theday theyusuallyfindshelterbeneathstones,boards,sidewalks,ordebris.Earwigsarerapidrunnersandmigrateshortdistancesinthismanner.LIFE CYCLE: Eggs are laid in small batches or clutches in achambertwotothreeinchesbeneaththesoilsurface.Themotherguardstheeggsandthenewlyhatchedyoung.Afterthefirstmolt,theyoungleavethenestandfendforthemselves.Theydifferfromthe adults in color pattern, shape and size of forceps, lack ofwings, and body size. The young usually mature in one season.Mostspeciesinthiscountryhaveonegenerationperyear,overwinteringaseggsoradultsinthesoil.Eggsandyoungrequiremoisture.Heavyrainsaredetrimentaltobothforms,asarerapidtemperaturechanges.TYPEOFDAMAGE:Althoughmostarescavengers,somefeedon livingplantsandoftenbecomepests ingreenhousesandfieldcrops.CONTROL: Chemical control consists of applications made outdoors, since the problem originatesoutdoors,aparameterspray5-10feetoutsidethehousewillreducethenumbersthatgetinside.Removingdebristhatshelterearwigsmayenhancetheeffectivenessofchemicaltreatment.Checktomakesuresealsonwindowanddoorsareintactandnotallowingearwigsinside.Rakeandreducemulchsothatit’sthinneranddriesoutquicker. If earwigshavegainedentrance toabuilding, indoor treatmentmaybedesirable,althoughthoseindoorswilldieeventuallywithouttreatment.

OUTDOORCHEMICALAPPLICATIONS:Applyinsecticidesaroundthebuildingfoundation, insub-floorcrawlspaces,andtoflowerbedsandturfwithinacoupleofyardsofthebuilding. Mulches in such flowerbeds should be treatedthoroughly from top to bottom. Apply sprays in lateafternoon if possible so that residues are freshwhen theearwigs become active in the evening. Earwigs areprotectedduringthedaywhentheyarebeneathdebrisorbelow the soil surface. Apply insecticides at the raterecommendedonthelabel,butusesufficientwatersothatthetoxicantiscarrieddowntothezonewheretheearwigsareactive.INDOORCHEMICALAPPLICATIONS: Indoortreatmentisonlyasupplementtooutdoortreatmenttoeliminatethoseearwigs already indoors. Indoor treatment alonewill notsolve theproblem.Use aerosol insecticides registered forindooruse.Indoortreatmentgenerallyconsistsofresidualspraysappliedtobaseboards,beneathcabinets,andotherhidingplacesatfloorlevel.Formostearwigtreatmentindoors,insecticidesusedforcockroachesareeffective.INTERESTING FACTS: Some tunnel as deeply as six feet into the ground to escape the cold. The nameearwigisfromaEuropeansuperstitionthattheseinsectsenteredtheearsofasleepingpersonandboredintothebrain.Thisbeliefistotallyunfounded.