Research Focus 2013-2: Cornell Viticulture and Enology 1

Key Concepts

• Grapeberrymothlarvaefeedinsideberries,soeffectivecontroldependsupontargetingeggsandlarvaebeforetheystartfeed-inginternally.

• Pheromonelurestomonitormothsareoflimitedvalueinpre-dictingegglayingandtimingforinsecticideapplications.

• Currentrecommendationsusingcalendardateapplicationsof-tenmissthe‘window’forthe2ndand3rdbroodegglayingandlarvaldevelopmentinwarmerorcoolerthanaverageyears.

• Accurate timing ismore importantwithmanynewer insecti-cidesthathavereplacedbroad-spectrumorganophosphateandcarbamateinsecticides.

• Bytrappingfemales,wewereabletovalidateatemperature-drivendegree-daymodeltopredictthetimingofGBMgenera-tions(810growingdegree-days/generation).

• Timingofegglayingforthefirstgenerationiscloselylinkedtobloominwildgrapevines.

• Growerscanusewildgrape‘bloomdate’andgrowingdegreeday models to time insecticide applications targeted at mid-summerandlaterGBMgenerations.

• ShortdaylengthafterAugust4thinduceseggslaidafterthatdatetostopdevelopmentatthepupalstageforoverwintering.

• Earlyandhotsummersbeforethediapausecutoffleadtoanadditional generation and high late-season populations ofGBMlarvae,oftenpersistinguntilharvest.

• Additional insecticide applications may be needed to limitdamageinwarmerthanaverageyears.

Focus on Females Provides New Insights for Grape Berry Moth Management

Michael Saunders1 , Rufus Isaacs2 and Greg Loeb3

1Dept. of Entomology, Pennsylvania State University, University Park, Pennsylvania 2Dept of Entomology, Michigan State University, East Lansing, Michigan 3Dept. of Entomology, Cornell University, New York State Agricultural Experiment Station, Geneva, NY

ResearchNewsfromCornell’sViticultureandEnologyProgram ResearchFocus2013-2

PhotosbyTimWeigle(top)andMikeSaunders(bottom)Since the grape berry moth (GBM) sex phero-mone was identified in the late 1960s, phero-mone lures and traps (top) have been an impor-tant tool for research and management. How-ever, because they solely attract males, they pro-vide only an indirect measure of when female GBM are active and laying eggs. Studies using passive malaise traps (bottom) have enabled us to track female GBM activity directly and pro-vided new insights on the timing of egg-laying and larval development. These will provide more precise, temperature-driven models to predict GBM activity in vineyards, which is increasingly important as older broad-spectrum organo-phosphate and carbamate contact insecticides are replaced with new narrow-spectrum insecti-cides which are only effective if they contact eggs or are ingested by larvae.

Research Focus

2 Research Focus 2013-2: Cornell Viticulture and Enology

Recent research in Michigan demonstrated a one ton/acre yield loss by GBM infestation associated with 50% of clus-ters infested with GBM (Roubos et al 2013). However, much lower infestation levels (in the range of 15% cluster infesta-tion) will cause rejection of grape loads by major juice pro-cessors, who inspect grape deliveries for GBM. Increased incidence of fruit rots associated with GBM can also lead to unacceptable levels of off-flavors in wine.

Monitoring tools. The male sex pheromone, identifiedin the 1970s, promised a means of population controlthroughthematingdisruptiontechnique(seeDennehyetal.1991).Whenlureswereusedinwingtraps(seephoto,firstpage)theywerelesseffectiveinmonitoringthepeaksandvalleys inGBMpopulationgrowthbecause the sexpheromone only attracts males. Counts of males fromsexpheromonetraps(Figure 4,top)oftenshowedalargepeakearlyintheseason,butshowednoclearpatterninthesecondhalfofthegrowingseasonandallowednopre-dictionsofwhenfemaleswouldbeactivelylayingeggsinthevineyard.

Incontrast,malaisetraps,atypeofpassivetrapthatcap-turesbothfemalesandmales,indicatedthreetofourdis-tinctpopulationpeaks,correspondingtofourgenerations(Figure 4,bottom). Anticipatingthesepeaks,whichcanlast 7 to 10 days in the 2nd generation, provides a solidbasisfortimingofcontrolmeasurestocoincidewiththepeak period of effectiveness. The key to improving thetimingandeffectivenessofinsecticidesprayswastode-velopa temperature-drivenmodel topredictperiodsofGBMactivityand,inparticular,egglayingbyfemales.

Introduction. Thegrapeberrymoth(Paralobesia viteana;GBM)isthemostsevere insect pest of grapes in theeasternUnited States.Amember ofthe Tortricidae family of leafrollingmoths,GBMundergomultiplegen-erationsperyear,andduringwarmgrowing seasons they can occur inverydamagingnumbersatharvest.

Effective control of GBM requiresprecise information about the tim-ingofegglayingandlarvaldevelop-ment. Until recently, it was unclearhow many generations GBM com-pleteinasingleseason,howlongittakesforaGBMeggtodeveloptoanadult,howtemperatureaffectstheseprocesses, and how and when dia-pauseisinitiated.

Life Cycle. GBM overwinter as pu-pae (Figure 2), which emerge fromdiapause as adults in the spring tomate and lay single eggs onto theoutside of grapes. After hatching,theyoungGBMlarvaechewtheirwayintothegrapeber-ry,oftenfeedinginmultipleberriestocompletedevelop-ment.Pupationtypicallyoccursoutsidethegrapeberry,underflapsofbarkorinthesoillitter;rarelyonewillseea pupa in a rolled leaf edge as is characteristic ofmostTortricidmoths.Afterpupation,theadultstageemerges,mates, and lays eggs to establish thenextgenerationofGBM.Atsomepointlateinthesummer,GBMwillstopdevelopmentatthepupalstageand,ratherthancompletedevelopmenttotheadultstage,willenterarestingstage(diapause)tosurvivethroughthewinter.

Economic Injury. GBMlarvaecausedirectdamagetober-ries through feedingand indirectlyby creating sites forpathogens likeBotrytis bunch rot todevelop (Figure 3).Directyieldlossismodest,unlesstheinfestationisheavy.

PhotosbyJ.Ogrodnick(l)andG.Loeb(r)

Figure 3. At left, Concord cluster with multiple berries showing dam-age from GBM larvae and characteristic webbing within the cluster. Right, Chardonnay cluster with Botrytis bunch rot.

LifeCycleoftheGrapeBerryMoth

Figure 2. GBM overwinter as pupae (bottom row), which emerge as adults in the spring (top left) and lay single eggs on grapes (top middle). GBM larvae (top right) feed inside the grape berry, often requiring multiple berries to complete development.

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the 47.14 °F threshold) are required for 50%of thepopulationtodevelopfromeggtoadult.Additionaldegreedaysmustbeaccumulatedforthefemaleovariestomatureandformating,resultinginatotalofapproximately810degreedaysfor50%ofthepopulationtotransitionfromtheeggstothenextgeneration’seggstage.

When do GBM adults first appear in the vineyard?ThefirstemergenceofoverwinteringGBMadultsinthespringoccursaftertheaccumulationofapproxi-mately270degreedays(DD°F),countingfromJanu-ary1ofthatcalendaryear.Atapproximately342DD°F,50%oftheGBMwillhaveexiteddiapause,andatabout418DD°F,90%oftheoverwinteredGBMwillhaveemergedfromdiapause.When compared to thedevelopment ofmost culti-vatedgrapes,thesedatesofGBMemergenceareveryearly.InfactGBMemergefromdiapauseweeksbe-fore bloom in cultivated grapes, and egg laying iswell synchronizedwith the earlier bloomof nativewildgrapes.Thedateofwildgrapebloomisause-fulproxyforGBMemergenceandisusedasa‘bio-fix’,orcriticalstartingdateforthedegreedaymodeldescribedbelow.GBM’ssynchronizationwithwildgrapebloommeans thatmostfirst-generation eggsarelaidonwildgrapes,ratherthancultivatedgrapes.

Degree-Day Model. TobetterunderstandGBMwithin-seasonpopulationdynamicsanddevelopimprovedmethodsforGBMmanagement,weconductedaseriesofstudiesinPennsylvania,NewYork,andMichiganoverseveralyearstodeterminethreefundamentallifehistoryprocessesofGBM:

• How long does it take forGBM to develop from egg toadult?

• Whendothefirstpupaeemergefromwinterdiapauseinthevineyard?

• Whendoyoulastseetheminthevineyard?How long does it take for an egg to mature into an adult GBM?TodeterminethetimeittakesforGBMtodevelop,mothcolo-nieswererearedingrowthchambersatconstanttemperatures(Figure 5). Insect growth and development is temperaturedependent, andGBM reared in cooler temperatures developmoreslowlythanGBMrearedinwarmertemperatures.GBMcannotgrowanddevelopattemperaturesbelow47.14°F,andabovethatthreshold,755degreedaysFahrenheit(thesummedaverageofminimumandmaximumdailytemperatures,minus

Photo by Terry Bates

Figure 4. Seasonal population trends revealed by pheromone lures (top) targeted at male GBM (top) often showed a large peak in the springtime, and no distinct peaks in mid-season, providing little guidance for tim-ing midseason insecticide applications. Malaise traps, which capture both males and females (bottom), have revealed three to four distinct generations, which provide discrete windows for sprays targeted at peak egg-laying times during the growing season.

Figure 5. The number of days to complete development decreases with increasing temperature (top graph). The developmental rate (the proportion of development that occurs per day) increases with increasing temperature (bottom graph). Note that at very warm temperatures (> 34 °C/ 93 °F) development stops (upper developmental threshold). The lower developmental threshold (temperature where no development occurs) is estimated to be about 8.4 °C/47.1 °F.

4 Research Focus 2013-2: Cornell Viticulture and Enology

When do you last see GBM in the field?Manyinsectspe-ciesintemperateclimateslikeoursundergodiapausetoescape the stresses ofwinter. Cues for impendingwin-terincludechangesindailytemperature,humidity,hostplantquality,ordaylength.Decreasingdaylength(alsocalled the photoperiod) at the egg stage is the environ-mental cue that inducesdiapause inGBM (Figure 7). Ifaneggislaidwhendaylengthis13hoursorless,itwillenter diapause at the pupal stage rather than completedevelopmenttotheadultstage.Ifaneggislaidatwhendaylengthexceeds15hours,itwilldevelopthroughthepupalstageintoamatingadultandproduceanothergen-erationofeggs.Eggslaidatphotoperiodsbetween13and15hourswillhaveintermediatelevelsofdiapause.

Thisday-length cue is a key andpredictable factor, be-causeonagivendateatagivenlatitude,thephotoperiodis always the same. For example, at the latitudeof theLake Erie grape belt, an egg laid on July 22, when thephotoperiodis14hoursand45minuteslong,hasa50%chanceenteringdiapausewhenitreachesthepupalstage;anegglaidonAugust3,whenthephotoperiodis14hours21minutes long,hasa90%chanceofenteringdiapausewhenitreachesthepupalstage(Figure 7,bottom).

Our data on temperature-driven developmental rates,identificationofwildgrapebloomas a ‘biofix’, and theknowledgeofwhendecreasingdaylengthinducesGBMtostopdevelopmentatthepupalstageandenterdiapause,hasprovidedasolidfoundationforpredictingpeakegg-layingdates–andtimingmanagementpractices.

Seasonality and Management. The picture we nowhaveofGBMseasonalityisthatadultswillemergeinthespring,mateandeach femalewill layapproximately20individualeggsdirectlyon the surfaceofgrapeberries.Theeggwillhatchandthelarvawilleatitswayintotheberry,withinwhichitwillfeeduntillarvaldevelopmentiscomplete.Thematurelarvawillexitthegrapeandpu-

pateeitherinarolledleaforinbarkcrevicesorinthesoil.Afterpupationiscomplete,adultswillemerge,mateandinitiate another generation. This pattern will continueuntillatesummer,whenshorterdaystriggerdevelopingeggstodiapauseinthepupalstage.Thepupawillover-winterandemergethefollowingspringtobeginthecycleanew.

Temperaturesduringthegrowingseasonwillaffecthowlongittakesforeachgenerationtomature,thereforetem-perature-basedpredictionsofGBMpopulationdynamicsarenecessarytoeffectivelymanagethistroublesomepestandtopreventseriousyieldlossesandloadrejectionsatgrapeprocessingplants.

Are late-summer infestations increasing? Somegrow-ersperceivethat late-seasonGBMproblemsare increas-ing.Therearemanypossiblecauses,includinginsectre-sistancetoexistinginsecticidesandthedifferentmodeofactionofnewerinsecticides.Whileolderbroad-spectruminsecticideskilledoncontactandhadvaporactiontopen-etratethedensecanopiesandclusters,manyofthenewercompounds available for GBM control are not contactpoisons;theymustbeingestedtohavethegreatesteffect.PreliminarystudiescarriedoutatPennStateUniversityhavedemonstratedthatGBMlarvaewithingrapeberriesareprotectedfrominsecticidesprays.Therefore,activein-secticideresiduesmustcovertheclustersurfacesduring

PhotosbyT.Martinson

Figure 6. Wild V. riparia with male flowers at bloom. V. riparia is the most common wild grape species growing in the northeast and north central regions of the United States. It typically blooms a week (150 degree days) before Concord vines.

FiguresbyM.Saunders

Figure 7. As daylight hours (or photoperiod) increase beyond 14 hours (top), most eggs will develop to pupae and not enter diapause. Put another way (bottom), daylight hours decrease the proportion of pupae that enter diapause increases. In the Lake Erie grape belt, most grape berry moth eggs laid after early August will enter diapause as pupae.

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thebriefwindowinwhichyoungGBMlarvaearechew-ingtheirwayoutoftheegg,throughthegrapeskinandintotheberry,orwhentheymovebetweenberries.

AnotherpossibleexplanationforrecentGBMcontrolfail-urescouldbeclimatechange.Iftheclimatewarmsevenslightly,thesecondgenerationofGBMmaycompletede-velopmentmorequicklyand layeggsbefore thecriticalphotoperiodthatinducesdiapause.Asaconsequence,theeggs laidby the secondgenerationofGBMwillnoten-terdiapauseaspupaebutwilldevelopintomatingadultswhich could initiate another damaging late season gen-erationintheperiodjustbeforeharvest,therebyincreas-

ingtheriskofclustercontamination.Furtherexacerbatingthisissueistheincreasingneedtoletgrapeshanglongertomeethigherbrixstandards.

From risk assessment to degree-day based management. Inrecentyears,thegrapeberrymothriskassessmentpro-tocol (GBMRAP) (Martinson et al. 1991, summarized inFigure 8)hasbeenusedbygrapegrowersintheeasternUnited States to estimate timing of insecticide applica-tionsforGBMmanagement.Althoughtherecommendedfirstsprayistiedtobloomtime,whichinturn,isdrivenbytemperature,theothertimingsarebasedsolelyoncal-endardateirrespectiveoftemperature.

GrapeBerryMothForecastingModelsAvailableOnlineinNewYork,Pennsylvania,andMichigan

NEWAGBMForecastingSite

MichiganStateEnviroweatherSite

TheGBMforecastingmodelhasbeenincorporatedintoonlineadvisoryprogramstopredictdatesofGBM egg-laying and to time insecticide applica-tions.Cornell’sNetworkforEnvironmentalandWeath-erApplications (NEWA)providesonsiteweatherinformation to over 50 locations in NY and PA,andauser-friendlymodel (right, top) toprovidesite-specificpredictions.Afterenteringthe‘biofixdate’(50%wildgrapebloom)andselectinganear-byweatherstation,theprogramprovides:

• Degreedayaccumulationssincethebiofixdate

• A forecast of degree day accumulation overthenextfivedays

• The predicted pest status and managementrecommendationsfortheirvineyard.

Michigan State has a similar GBM forecastingprogram calledEnviroweather,with close to 100weatherstationsstatewide.

6 Research Focus 2013-2: Cornell Viticulture and Enology

BecausedevelopmentofGBMistempera-ture dependent, the GBMRAP timingsfor controlusing contact insecticidesmayworkfairlywellinanaverageyear,butincool years theymay be applied too earlyandinwarmyearstheymaybeappliedtoolate.Hence,atemperaturebaseddevelop-mentorphenologymodelshouldprovidegrowers with a more reliable method totimemanagementactionsadjustedforeachyear’sconditions.

To implement a degree-day approach forGBMmanagement, a start date for accu-mulatingdegree-daysmustbedetermined.The bloom date of the earliest floweringgrapevinespeciesinanareashouldbethedate from which degree-days are accu-mulated forGBMpopulationmonitoring,whichwecallthebiofixdate.

From thebiofixdate, theaccumulationofdegree dayswill determine the timing ofpopulationdevelopmentandkeyopportu-nitiesforeffectiveinsectcontrol.Arollingtotalofdegreedaysismaintainedtoiden-tifywhen each generation is predicted tobelayingeggs:thefirstgenerationat810degreedays,thesecondgenerationat1620degreedays,and—ina longhotsummer--thethirdgenerationat2430degreedays.

The GBMRAP suggested a 10 day post-bloomsprayforfirst-generationGBMcon-trol.BecauseitnowappearslikelythatthefirstflightofGBMissynchronizedwiththewild grapes where most oviposition willoccur,wenolongerrecommendanytreat-mentforthisfirstflight.EffortsdirectedatchemicalcontrolofGBMshouldbetarget-edatthesecondandsubsequentegglayingperiods of GBM (i.e. the offspring of theoverwinteredGBM).ThissecondperiodofegglayingtypicallyoccursinJulyinMichi-ganandintheLakeEriegrapebelt,anditcanvary fromveryearly in themonth inwarmyearstolaterinthemonthincooleryears.Thenextgeneration’segglayingisapproximatelyonemonthlater,againbasedontemperature.

Comparing management programs. WehavecomparedGBMRAPwithtemperature-drivenmodelstotimespraysincommercialvineyardconditionsinMichigan,Pennsyl-vaniaandNewYork.WecomparedGBMdamageinvine-yardblockswherespraytimingswerebasedonGMBRAP(calendar-based)withdamageinvineyardblocksprayedbased on degree-day accumulations (temperature-driv-en).Theresultshaveconsistentlyshownthatspraytiming

Martinsonetal1991.

Figure 8. GBM management recommendations based on the Grape Berry Moth Risk As-sessment Protocols developed by Cornell entomologists in the late 1980s. Note that timing for mid and late season management decisions is based on the calendar date.

basedontemperature(seeFigure 9foranexamplefromMichigan)resultsinlessGBMdamage.

Putting it all together.Grape growers in theNortheastandNorthCentralregionsarenowabletotakeadvantageof temperature-driven,predictivemodels tobetterman-age thisdestructive insect. Aspart of a regionalNorthEastIPM(NEIPM)fundedproject,thisnewinformationhasbeenbuiltintoaGBMdegree-daymodelandincorpo-ratedintotheNEWAsystemofweatherstationsinNewYork,Pennsylvaniaandsurroundingstates(seesidebar).InMichigan,fundingfromProjectGREEENsupportedin-corporatingthesamemodelbeingintotheEnviroweather

FigurebyRufusIsaacs

Figure 9. Berry moth infestation in clusters through the season in Michigan vineyard plots treated with a program of broad-spectrum insecticides applied using traditional tim-ings (Standard = GBMRAP) or guided by the degree day model (Standard GDD), or pro-grams using Danitol or Intrepid applied at growing degree day-based timings for optimal selective insecticides. The lines show the percent of clusters infested through the season and illustrate the superior control achieved with two applications of Intrepid (810 and 1620 growing degree days). The numbers to the right show the surviving grape berry moth from infested clusters collected just before harvest and the approximate cost of the programs.

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site.ThesestationsrecorddailyweatherstatisticsandwillcalculatethestatusofGBMpopulationsoverthecourseofthegrowingseason.Thesesystems(seesidebaronp.5)automatecalculationofthefollowingsteps:

1.Beginningfrom(50%)bloomdateoftheearliestoccur-ringgrapevarietyinyourarea,likelyawildgrapesuchasV. riparia, V. labrusca, V. cordifolia,recordthedailyhighandlowtemperature(inFahrenheit).Addtheseanddividebytwotogetaveragedailytemperature.

2.Subtract47.12fromthedailyaveragetemperature.ThisresultsintheGBMdegree-daytotalforthatday.

3.Continuetocalculatedailydegree-daysandmaintainarollingtotal.

4.Whenyouaccumulate810DD,thesecondgenerationofadultsispredictedtostartlayingeggs,andaspraytoprotectclustersfromGBMisrecommendedinhighandpossiblyintermediateriskvineyards.

5.Repeat for thenext generation.At 1620DD, itwill betime to treat the clusters toprotect them from the thirdgenerationofGBM.

6.Ifyouhaven’tharvestedyetat2430DD(anindicationofalong,hotsummer),anotherspraymayberequiredtoprotectgrapesfromafourthgeneration.

InvineyardswherethereisaneedtoprotectclustersfromGBM infestation, the degree daymodel for this pest isvaluableforhighlightingthetimeintheseasonwhenin-secticidescanbeusedtogreatesteffect.Themodelismostusefulforhelpingmakethedecisionofwhentostartpro-tectingclustersfromthesecondandthirdgenerationegglaying,startingat810and1620degreedays,respectively.

Sprays for thefirstgenerationatbloom timehavebeenfound to haveminimal effect on the amount of infesta-tionatharvesttime,sowestronglyrecommendgrowersfocustheir“GBMcontroldollars”onachievingexcellentcontrolofthesecondandthirdgenerations.

Inaddition,becausepestpressure ishigherat thevine-yard border--especially adjacent to woods, gullies, ortreelines--growerscanfocustheirinsecticideprograminthesemoreat-riskareasof theirvineyardstomakesuretheseregionsareprotected.

Thelateseasonpresentschallengesforbothmanagementandmodeling. Inwarmer than average years, the thirdgeneration of GBM can emerge and lay eggswhen thephotoperiod is still quite long, and therefore few if anyeggswill be programmed to enter diapausewhen theyreach the pupal stage. These eggswill develop directlyintoadultsandinitiateanadditionalgenerationinthelateseason.Itisthisgenerationthatwillbepresentatharvest,potentially resulting in severe crop loss and load rejec-tions.

Furthermore,becauseoftheextendedperiodofdiapauseterminationinthespring,bylatesummerthegenerationsmaybegintooverlapwithoneanotherleadingtotheneedforcontinuousspraycoverageforlateseasonprotection.ThewarninggivenbytheNEWAsystemisasfollows:

“If 1620 DD occurs prior to August 5, you can expect continu-ous pressure from grape berry moth through harvest. Model re-sults are not good predictors of timing of population pressures. Multiple additional insecticide applications may be necessary in high pressure vineyards to address the extended egg-laying and overlapping generations. Continuous coverage is necessary to avoid excessive crop loss. NOTE: Insecticide applications af-ter mid September will have limited effectiveness in preventing damage.”

Different insecticides require different timing. Toprop-erly time different insecticides, some understanding ofthe different types of insecticides registered for use invineyardsisrequired.

• Activity against eggs and new larvae:Thosethathaveac-tivityoneggsandworkwellwhenthelarvaishatch-ingshouldbeusedcloseto(orat) thesedegreedaytargettimings.Thiswillhelpgetthemosteffectfromtheiractivityon theyounger stages,and inparticu-larweconsiderIntrepid, Altacor,andBelttobethreeexcellentoptions for theseearly egg laying timings.Thesethreeproductsalsohavelongresidualactivity,arerelativelyrainfast,andhave lowimpactonben-eficialswithgoodworkersafety.Makesuretheyareapplied with excellent cluster coverage, and adjustyoursprayerifneededtomakesurethattheclusterzoneistargetedwithsufficientwatertoget intothenooks and crannies of the clusters. These productsalsobringnewmodesofactiontohelpwithyourre-sistancemanagement.

• Broad-spectrum contact insecticides: For those grow-erslookingtousemorebroad-spectruminsecticidesincludingoneofthemanypyrethroidsregisteredinvineyards, such as Danitol, Baytroid, or Mustang Max,acarbamatesuchasSevin,ortheorganophos-phate Imidan (watch the 14 day REI and PHI!), itisworthwaitingaweekor so from thedateswhenyoureach810or1620GDDbeforespraying.This isbecausemost of the broad-spectrum insecticidesdonothavetwotothree-plusweeksofresidualactivity.So,waiting100GDDto910and1720willensurethattheseinsecticidesarepresentandmostactiveduringthemainbulkoftheGBMegglayingandespeciallytheegghatchperiodwhenthesmalllarvaearewalk-ing across theberries tofindaplace to feedon thefruit.

• Short-residual, repeated application: For short-lived in-secticides such as a pyrethroid or Sevin , it is alsoadvisabletomakeasecondapplicationafter10to14days to those areas of vineyardswhere there is thehighest pressure fromGBM (e.g., edges adjacent to

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mology106:905-911.

Teixera,L.,Mason,K.S.,VanTimmeren,S.,andIsaacs,R.(2011)SeasonalpatternofovipositionbytheNorthAmericangrapeberrymoth(Lepidoptera:Tortricidae).JournalofAppliedEn-tomology135:693-699.

AcknowledgementsTheresearchreportedwasfundedbyNIFA-RIPMawards#2010-41530-21275 and #2010-34103-21274, the Viticul-turalConsortium-East,theUSDA-CSREESCropsatRiskProgramproject2005-51100-02363,NationalGrapeCoop-erative,ProjectGREEEN,theMichiganGrapeandWineIndustryCouncil,NewYorkWineandGrapeFoundation,and theNewYorkState IPMProgram, and support ofthegrape industryandgrowers inPA,NY,andMI.WearealsoindebtedtoPatrickTobin,SudhaNagarkatti,JodyTimer,AndyMuza,TimWeigle,KeithMason,StevenVanTimmeren,LuisTeixeira,CraigRoubos,andSteveHeslerfortheirmanycontributionstothisworkovertheyears.

The information, including any advice or recommendations, contained herein is based upon the research and experience of Cornell Cooperative Extension personnel. While this infor-mation constitutes the best judgement/opinion of such personnel at the time issued, neither Cornell Cooperative Extension nor any representative thereof makes any representation or warrantee, express or implied, of any particular result or application of such information, or regarding any product. Users of any product are encouraged to read and follow product-labeling instructions and check with the manufacturer or supplier for updated information. Nothing contained in this information should be interpreted as an endorsement expressed or implied of any particular product.

Cornell University provides equal program and employment opportunities.

woods).Thiswillhelptocoverthewholegenerationuntilthestartofthenextoruntilharvest.Forallinsec-ticide-relateddecisions,rememberthatthelabelisthelawandtherearesomevariations inwhatproductsare registered inMichigan, Pennsylvania, andNewYork.Talktoyourlocalextensioneducatorandcon-sult the local recommendations to learnmoreaboutthistopic.

Summary. Grapeberrymothhasbeenapestinvineyardssince the dawn of viticulture inNorthAmerica. Recentinsightsintothebiologyandtimingofthispest’sdevel-opment,whencoupledwithmodernweathermonitoringsystems,providegrowerswithmoresophisticated toolsforGBMmanagement.Inparticular,thedevelopmentofthe810and1620 targets for the startof the secondandthirdperiodsofGBMegglaying(typicallyinJulyandAu-gust)cangreatlyassistinansweringthatage-oldquestionof when to spray.When combined with sampling andknowledgeofpestdistribution invineyards, thedegreedaytimingsandonlinedecisiontoolsattheNEWAandEnviroweather websites provide a way to adjust spraytimingsbasedontheyear’sweather,ratherthanthecal-endar. Using this approach in combinationwith newerinsecticidesthathavelowerimpactonbeneficialsandim-provedworkersafetywillgreatlyenhancegrowerabilitytoreducetheeconomicimpactofGBMinvineyards.ReferencesDennehy,T.J.,Clark,L.andKamas,J.(1991).Pheromonalcon-trolofgrapeberrymoth: aneffectivealternative to conven-tionalinsecticides.NewYork’sFoodandLifeSciencesBulle-tin,number135.

Isaacs,R.,Teixeira,L., Jenkins,P.,BoteroNeerdals,N.,Loeb,G.,andSaunders,M.(2012)Biologyandmanagementofgrapeber-rymothinNorthAmericanvineyardecosystems.pp.361-381.In:Arthropod Biology andManagement in Vineyards: Pests,ApproachesandFutureDirections.Eds:N.Bostanian,R.Isaacs,andC.Vincent.Springer.

Martinson, T., Hoffman, C.J., Dennehy, T.J., Kamas, J.S., andWeigle,T. (1991).Risk assessment of grapeberrymoth andguidelines formanagementof theeasterngrape leafhopper.NewYork’sFoodandLifeSciencesBulletin,Number138.

Roubos,C.K.S.Mason,L.Teixeira,andR.Isaacs(2013).Yield-based economic thresholds for grape berrymoth (Lepidop-tera:Tortricidae) in juicegrapes. JournalofEconomicEnto-

Michael Saunders is a professor of entomology at Penn-sylvania State University with research expertise in in-sect ecology and decisions support systems.

Rufus Isaacs is a professor of entomology at Michigan State University with research expertise in insect ecol-ogy, pollination ecology and pest management.

Greg Loeb is a professor of entomology at Cornell Uni-versity and the New York State Agricultural Experi-ment Station in Geneva, New York with research exper-tise in insect ecology and pest management.