COCKROACHESGary W. Bennett, Extension Entomologist

TherearefivekindsofcockroachescommonlyfoundinIndiana.Theyvarysomewhatinappearanceandhabits,butingeneraltheyareallratherlarge,flattenedinsects,brown-ishordarkincolorandfastmoving.Roachesseekconceal-mentinthedaytimeandalsowhendisturbedatnight.Theymaybecarriedintohomesinboxes,eggcartons,beveragecases and produce such as potatoes. In apartments andotherlargebuildings,theyreadilymigratefromoneplacetoanotheralongwaterpipes. KINDS OF ROACHES The German roachisaverycommonspeciesandtheoneusuallyfoundinkitchens.Theadultsarecomparativelysmall(about1/2inchlong),tanincolorandoftenoccurinlargenumbers.The immatures (nymphs)havedarkmark-ingswhichmakethemappeardarkbrowntoblack. The American roachisreddish-brownandisthelarg-est of the common roaches (about 1-1/2 inches in lengthatmaturity). It is foundmoreoften in foodestablishments,althoughhousesandapartmentsnearsuchestablishmentsfrequentlybecomeinfested. The Oriental roachisalsolarge(about1inchinlength)andshinyblackorverydarkbrown.Itisoftencalleda“waterbug” or “black beetle.”This species is frequently found indampnessandmayenterhomesthroughseweropenings.Itmaylikewiseliveoutdoorsduringthesummermonthsandmovefromhometohome. The Brown-banded roachisasouthernspeciesbutisoften found in Indiana. It resembles theGerman roach insizebutdiffersinhabits.Itmayinfesttheentirehome,rath-erthanconfiningitselftothekitchenorwherethereisfood.Infestationsusuallystartfromluggage,furnitureorotherma-terialsshippedfromoneplacetoanother. The Woods roach normallylivesundertheloosebarkofdeadtrees,logsorstumps.Itsometimesinvadeshomesbuiltinornearwoodedareas,butitdoesnotthriveindoors.Males are nearly 1 inch long and dark brownwith a palestripe on the outer margins of the wings. They are fairlygoodfliersandoftenenterhomesthisway.Theycanalsobecarriedinonfirewood.Thefemalesareshort-wingedandresembletheOrientalroach,buttheyareseldomfoundin-doors.

A B C

D E

CockroachescommontoIndiana:A.German,B.American,C.Oriental,D.Brown-banded,E.Woods.Seedescriptions

foractualsize.

CONTROL MEASURES AND MATERIALS Thechancesofeffective,lastingcockroachcontrolaregreatly increased if thorough sanitation preceeds properchemicalapplication.Thedestructionofbreedingplaces(byclearingoutgarbageandclutter,sealingcracksandopen-ings,etc.)andtheremovaloffoodandwatersourcesmayreducethenecessityforchemicalapplications. There are a number of insecticides, and usually nu-merousformulationsandwaysofapplyingeachinsecticide,thatmaybeused for cockroach control.Baits and sprays(labelledascrawlinginsectcontrolmaterials)arethemosteffective.Dustsorpowdersarealsoavailable,butaremoredifficulttouse.Traps(withastickysubstanceinside)canbepurchasedandusedforpinpointingareaswherecockroach-esarelocated,butusuallyhavetobecombinedwithbaitsorspraystoobtainsatisfactorycockroachcontrol.Baitsareeasy to use, and are best for areaswhere contaminationwithspraysordustsmightbeaproblem,suchasnearfoodordishes.

E-23-W

Household and StructuralDepartment of Entomology

Cockroaches— E-23-W 2

READ AND FOLLOW ALL LABEL INSTRUCTIONS. THIS INCLUDES DIRECTIONS FOR USE, PRECAUTIONARY STATEMENTS (HAZARDS TO HUMANS, DOMESTIC ANIMALS, AND ENDANGERED SPECIES), ENVIRONMENTAL HAZARDS, RATES OF APPLICATION, NUMBER OF APPLICATIONS, REENTRY INTERVALS, HARVEST RESTRICTIONS, STORAGE AND DISPOSAL, AND ANY SPECIFIC WARNINGS AND/OR PRECAUTIONS FOR SAFE HANDLING OF THE PESTICIDE.

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November 2017

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Cockroachcontrolmaterialsarenowavailableinlow-pressure spray containers (aerosol cans) that apply a re-sidualdepositoftheinsecticide.Applytheminabout2”widebandswherecockroacheshide,suchasincrevicesnearthekitchensinkandstove,underneathand insidecupboards,aroundpipesandconduitswheretheypassalongorthroughwalls, inandaroundwaterheaters, inside themotorcom-partment of refrigerators, and behind skirting boards,mir-rors, and pictures.Also, treat garbage cans and other re-fuse containers. Pressurized sprays of this type are quitesatisfactory.However,theyshouldnotbeconfusedwiththehigh-pressure“aerosolbombs”(total releaseaerosols)de-

signed forapplyingspacesprays.The latterareof limiteduse incockroachcontrol,with theadditionaldisadvantagethatoccupantsmustevacuatethepremiseswhiletreatmentisunderway,andwithoutproperprecautionssomecanstartfires. Anumberofelectronic/ultrasonicdevicesthataresup-posedtokillorrepelcockroachesarenowbeingsold.Mostofthesedeviceshavenotbeentestedthoroughlyenoughtodetermineiftheyareeffective.Anumberoftheseunitshavebeenremovedfromthemarketplacebygovernmentagen-ciesaftertheywerefoundtohavenoeffectoninsectpests.

ScientificNames:

Germancockroach—Blattella germanica(Linnaeus)Americancockroach—Periplaneta americana(Linnaeus)Orientalcockroach—Blatta orientalis (Linnaeus)Brown-bandedcockroach—Supella longipalpa(Fabricius)Woodscockroaches—Parcoblatta spp.Orientaladultcockroach

Germanadultcockroach

Americanadultcockroach

Brown-bandedadultcockroach

Woodadultcockroach