May 4, 2020 OPP Docket 1200 Pennsylvania Ave. NW ... · neonicotinoids continuously stimulate...

May4,2020

OPPDocketEnvironmentalProtectionAgencyDocketCenter(28221T)1200PennsylvaniaAve.NW.Washington,DC20460-0001RE:CenterforFoodSafety’scommentstoEPAontheProposedInterimRegistrationReviewDecisionsforSeveralNeonicotinoidPesticides:Imidacloprid,Clothianidin,Thiamethoxam,AcetamipridandDinotefuranDocketIDs:EPA-HQ-OPP-2008-0844: ImidaclopridEPA-HQ-OPP-2011-0865: ClothianidinEPA-HQ-OPP-2011-0581: ThiamethoxamEPA-HQ-OPP-2011-0920: DinotefuranEPA-HQ-OPP-2012-0329: AcetamipridCenterforFoodSafetyappreciatestheopportunitytocommentonEPA’sproposedinterimregistrationreviewdecisionsfortheabove-namedneonicotinoidinsecticides.

HUMANHEALTHASSESSMENTCommonMechanismofToxicityDemandsCumulativeRiskAssessmentThesefiveneonicotinoidsoperatebydisruptingneuraltransmissioninthecentralnervoussystemofinvertebrates.Bybindingtonicotinicacetylcholinereceptors(nAChRs)inthebrain,neonicotinoidscontinuouslystimulateneurons,resultingindeathaswellassublethaleffects(Simon-Delsoetal.2015).NeonicotinoidsaremorehighlytoxictoinvertebratesthanvertebratesbecausetheformerhavehavealargernumberofnAChRswithhighaffinitytotheseinsecticides.NeonicotinoidstargetprimarilythenAChRsubtypeα4β2ininsectsandmammals,andmammaliantoxicitycorrelateswithagonistactionandbindingaffinityatthesereceptors,theirprimarytargetinthebrain(TomizawaandCasida2005).Thissharedmechanismoftoxicitydemandscumulativeriskassessmentoftheseneonicotinoids,asrequiredundertheFoodQualityProtectionAct.EPAprovidesnoexplanationforitsfailuretoconductacumulativeassessment,beyondnotingthatithasnotmadeanofficialfindingastothefactthatneonicotinoidsshareacommonmechanismoftoxicitytohumans(e.g.EPAImidacloprid2020,p.17).EPArefusedtomakethisfindingdespiteabundantevidence,eveninregistrant-sponsoredanimalfeedingstudiesconductedforthehumanhealthassessment,thatneurotoxicityisthemostprominentandconsistentclassof

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adverseeffectsofallfiveneonicotinoids.Forinstance,imidaclopridviaoraladministrationinducestremors,decreasedmotoractivityandsimilareffectsinmultiplestudiesonratsanddogs(EPA6/22/17,p.3).Clothianidininducesdecreasedarousal,motoractivityandacousticstartleresponse;tremors;andotherneurotoxiceffectsinvariousanimalstudies(EPA9/7/17,p.13).Thiamethoxamtriggersdevelopmentalneuorologicaleffectsinrats,includingreducedbrainsizeandweight(EPA12/5/17,pp.5-6).Neurotoxiceffectsinducedbyacetamipridincludedecreasesinlocomotoractivity,alertness,reactivity,spontaneousactivity,rearing,muscletoneandgripstrength;tremors;anddepressedreflexesinrat,mouseand/orrabbitstudies(EPA12/15/17,pp.17-18).Dinotefuranlikewiseinduceddeclinesinmotoractivity,gripstrength,andbrainweightinanimalstudies(EPA9/12/17,p.5).EPArefusestoofficiallyaffirmacommonmechanismofhumantoxicitybetweenanyoftheseneonicotinoidsdespiteacknowledgingthefact.EPAstatesthatneurotoxicityisamongtheclassesofadverseeffects“commonlyobservedinmammaliantoxicitystudiesofneonicotinoids”(EPA9/7/17,p.12).Stillmoreexplicitly,EPAaffirmsthatneonicotinoidshaveaneurotoxicmodeofactionbothforinsectpestsandhumans:“Dinotefuranisaneonicotinoidandhasapesticidalandmammalianneurotoxicmodeofaction.Consistentwiththismodeofaction,changesinmotoractivitywereseeninacuteneurotoxicity(ACN)andsubchronicneurotoxicity(SCN)studies”(EPA9/12/17,p.20).EPAalsonotesthatdinotefuraninduced“changesinmotoractivitywhichareconsistentwitheffectsonthenicotiniccholinergicnervoussystem[nicotinylacetylcholinereceptors,asnotedabove]seenafterrepeatdosing”(EPA9/12/17,p.5).Fourofthefiveneonicotinoidsbelongtoacommonsubclass–thenitroguanidines–whilethefifth,acetamiprid,isacloselyrelatedcyanoamidine-substitutedneonicotinoid(TomizawaandCasida2005,Figure1).EPA“madeaprogrammaticdecisiontoaligntheregistrationreviewscheduleforallfournitroguanidine-substitutedneonicotinoids(clothianidin,dinotefuran,imidaclopridandthiamethoxam)”(EPA1/16/20),andsubsequentlyaddedacetamipridtothegroup.Thisdecisionmakesnosenseif,asEPAtacitlyassumes,entirelyseparateriskassessmentsforeachofthemisadequatetothetaskofensuringhumanandenvironmentalsafety.Independentscientistshaveassessedcumulativedietaryexposuretoneonicotinoidsonthebasisoftheircommonmechanismoftoxicity,employingrelativepotencyfactorstopermitexpressionofthecumulativetoxicityinimidacloprid-equivalentunits(Luetal.2018;Zhangetal.2019).EPAhasusedthismethodtoassessthetoxicityofrelatedgroupsofcompounds,suchasdioxins(Staskaletal.2010).Becausecumulativeexposuretoneonicotinoidswouldbeconsiderablyhigherthanexposuretoanysinglecompoundofitsclass,EPAhasunderestimatedbothhumanexposuretoandthehealthrisksofneonicotinoids.Totakeoneexample,EPA’sestimateddietaryexposuretoimidaclopridaloneisnearlyequaltotheacutesafetythreshold(population-adjusteddose,oraPAD)forinfants(84%)andtoddlers(93%)(EPA6/22/17,p.23,Table5.4.4).Cumulativeexposuretoallfiveneonicotinoidswouldalmostcertainlyexceedtheacutesafetythresholdforthesevulnerablegroups.EPAshouldabstainfromanyfinalregistrationreviewdecisionuntilithascompletedathoroughcumulativeriskassessmentofneonicotinoids.

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SafetyFactortoProtectInfantsandChildrenEPAisrequiredbytheFoodQualityProtectionAct(FQPA)toapply“anadditionaltenfoldmarginofsafety”toaccountfor“thespecialsusceptibilityofinfantsandchildren,”andinparticularthe“potentialforpre-andpostnataltoxicity…,”andreduceoreliminateitonlyif“reliabledata”demonstrateitisnotneeded.AccordingtoEPApolicy,the10xFQPAsafetyfactoristobeappliedwhentheyoungexhibitincreasedsusceptibilitytoapesticide(i.e.effectsnotseeninadultanimals)orincreasedsensitivity(theeffectsoccuratlowerdosesorincreasedseverityintheyoung)(FQPA2002,p.30).Basedpurelyonregistrantstudies,EPAfoundincreasedsusceptibilityorsensitivitytoneurotoxicharmsinyoungtestanimalsversusadultanimalsforfourofthefiveneonicotinoidsatissuehere:imidacloprid(“evidenceofanincreasedquantitativesusceptility”intherat,”EPA6/22/17,p.14);clothianidin(same,EPA9/7/17,p.13);thiamethoxam(same,EPA12/5/17,p.6);andacetamiprid(“increasedqualitativesusceptibility,”EPA12/15/17,p.17-18).Despitethesefindings,theclearmandateoftheFoodQualityProtectionAct,andEPA’spolicyprescriptionsregardingimplementationoftheFQPA,EPArejectedthedefault10xsafetyfactorforallfiveneonicotinoids.EPAshouldabstainfromanyfinalregistrationreviewdecisionuntilithascorrectlyappliedtheFQPA10xsafetyfactortoarriveatreferencedosesthatreflecttheincreasedtoxicityoftheseinsecticidestotheyoung.IndependentStudiesRevealGreaterMammalianSensitivitytoNeonicotinoidsThanRegistrantStudiesKaraetal.(2015)administeredviagavage0.5,2or8mg/kg/dayimidaclopridtoinfantandadultWistarratsfor3months.Learningactivitieswerediminishedsignificantlyat2and8mg/kg/daydosesininfantrats,butonlyat8mg/kg/dayinadultrats.Thisstudy’sNOAELforinfantratsof0.5mg/kg/dayis16-foldlowerthanthe8.0mg/kg/dayNOAEL(acuteandchronic)basedonasubchronicdogstudyconductedbyBayerAGin1990.1Thisstudysupportsanoralreferencedoseof0.005mg/kg/day(vs.EPA’s0.08mg/kg/day),andalsoprovidesfurthersupportforretainingthe10xFQPAsafetyfactor,giventhegreatersensitivityofinfantvs.adultrats.Burkeetal.(2018)infused0.5mg/kg/dayimidaclopridintopregnantCD-1miceviaanimplantedosmoticminipumpfromgestationday(GD)4topost-natal(PN)day21.Imidaclopridaccumulatedinliversandbrainsofmaternalmice,andwasfoundintracelevelsinoffspring.Offspringexhibitedanumberofneurobehavioralimpacts:elevatedmotoractivity,enhanced

1RufJ.1990.NTN33893Technical:SubchronicToxicityStudyonDogsinOralAdministration(Thirteen-WeekFeedingStudy).LabProjectNumber:18732:100176.UnpublishedstudypreparedbyBayerAG.305p.MRID42256328.

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socialdominance,reduceddepressivebehavior,andadiminutioninsocialaggressioncomparedtocontrols.Adultmaleoffspringhadreducedweight.Maternalanimalshadsignificantlyreducedfecundity(roughly8vs.13pupspermotherfortreatmentvs.controlgroups).Transientexposuretoimidaclopridoverthedevelopmentalperiodinducedlong-lastingchangesinbehaviorandbrainfunctioninmice.BasedonBurkeetal.(2018),theLOAELforimidaclopridis0.5mg/kg/day.ThisstudyalsosupportsapplicationoftheFQPA10xsafetyfactory.

ENVIRONMENTALASSESSMENTCumulativeToxicityAswithhumanhealth,EPAmustassessneonicotinoidscumulatively,inviewoftheircommonmechanismoftoxicitytoinsectsandothernon-targetorganisms(Xerces2016),andtheirfrequentco-occurrence(e.g.Krupkeetal.2012).Maloneyetal.(2018)reportedroughlyconcentration-additivetoxicityofvariousneonicotinoidmixturestotheaquaticinsectChironomusdilutus,withmildsynergismforthiamethoxam-imidacloprid.EPAmustalsoassesstheadditiveorsynergistictoxicityofneonicotinoidstogetherwithco-occurringformulationadditivesadotherpesticides(Xerces2016).Togiveanideaofthescopeoftheproblem,Sanchez-BayoandGoka(2014)reportthatinvariousstudies,atotalof161pesticideshavebeenfoundinbeehives:124inpollen,95inwaxand77inhoneyornectar.Forinstance,neonicotinoidsarestronglysynergizedbyinhibitorsofCPY450detoxificationenzymes,suchaspiperonylbutoxide,acommon“inertingredient”inover2,500pesticideformulations(TomizawaandCasida2005;Crossetal.2017).Imidaclopridexhibitssynergyinconcertwiththeadjuvantnonylphenylpolyethoxylate,R-11,towardsthecrustaceanCeriodaphniadubia(Chenetal.2010).Awiderangeofotherformulationadditivesandsurfactants,suchasorganosiliconesurfactants,makepesticidesmoretoxicandcanalsobetoxicintheirownrights(Mullin2015,Chenetal.2018).Thisisproblematic,becauseregulatorytoxicitytestsontheactiveingredientalonewilloftenunderestimatereal-worldformulationtoxicity.Forthisreason,Zhuetal.(2017)testedthetoxicitytohoneybeeoftheimidaclopridformulationAdvise2FLinbinarycombinationswithsevenotherpesticidestheycommonlyencounter,andfoundsynergistictoxicitybetweenimidacloprid/AdviseandDomark/tetraconazole,Transform/sulfoxaflor,andVydate/oxamyl,withmortalitysignificantlyincreasedby20%,15%and26%,respectively.Tsevtkovetal.(2017)foundthatbothclothianidinandthiamethoxamweretwiceasacutelytoxictohoneybeeworkerswithco-exposuretofield-realisticlevelsofthefungicideboscalid.Neonicotinoidshavefrequentlybeenfoundtosynergizewithergosterolbiosynthesisinhibitor(EIB)fungicides(reviewedinWoodandGoulson2017).Thompsonetal.(2014)exposedhoneybeestosprayedfungicidesatrealistic,worst-casescenarioconcentrationsandvariousneonicotinoids.Theyfoundmildsynergismonacontactbasisbetweenthiamethoxamandtebuconazole(synergismratioof2.6)andonanoralbasisbetweenclothianidinandtebuconazole(synergismratioof1.9),withsynergismratioequivalenttotheLD50ofthe

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neonicotinoiddividedbythatoftheneonicotinoidsplusfungicidemixture.Similarly,Sgolastraetal.(2016)foundsynergisminthreebeespecies(A.millifera[honeybee],B.terrestris[bufftailedbumble]andO.bicornis[redmasonbee])exposedtoLD10dosesofclothinadinandanon-lethaldoseofthefungicidepropiconazole,intheformofincreasedmortalityforthemixture.Thesearejustafewofmanystudiesthathavearrivedatsimilarfindings,thoughbecausemostassessonlybinarymixturesandpollinatorsareexposedtofarmorecomplexcombinationsofmultiplepesticides,thereportedresultsarelikelytosubstantiallyunderestimatethedegreetowhichneonicotinoidsaresynergizedbyco-exposuretootherpesticides.YetEPAmakesnoattempttoassesstheincreasedrisksposedbyneonicotinoidsuponco-exposurewithotherpesticides.DeclinesinInsectPopulationsWorldwideCoincidewithRiseofNeonicotinoidsMassivedeclinesininsectandpollinatorpopulationsworldwideTherehavebeenmanyreportsofdeclinesinvariousinsectspeciesovertheyears(Dirzoetal.2014),forinstancetheover80%reductioninthemigratorymonarchbutterflypopulationssincethemid-1990sinNorthAmerica(Pleasants2015).However,recentlytherehasbeengreatinterestinchartingtrendsinoverallinsectabundanceasamorerelevantmarkerofecosystemhealth.Forinstance,researchersinGerrmanydocumentedanastounding76%declineinflyinginsectbiomassin63Germannaturereservesfrom1989to2016(Hallmannetal.2017).Theypositagriculturalintensification,includingpesticideuse,asonepotentialcause,notingthatmostofthepreservesaresurroundedbycroplandthatmayserveasanecologicaltrapsorsinksforinsectswhoseoriginsareinthenaturalareas.Sanchez-BayoandWyckhuys(2019)review73historicalreportsofinsectdeclinesaroundtheworld,andfindthatLepidoptera(mothsandbutterflies),Hymenoptera(beesandwasps)anddungbeetleshavebeenmostimpactedamongterrestrialinsects.Theypredictextinctionof40%ofremaininginsectspeciesinthenextfewdecades,andregardhabitatlosstoagricultureandurbanizationaswellaspollution,particularlyfrompesticidesandfertilizers,asmajordrivers.Arecentmeta-analysisofstudiesacrosstheworldfindsaroughly9%reductioninterrestrialinsectabundanceperdecade,atrenddrivenlargelybyfindingsinNorthAmericaandpartsofEurope(vanKlinketal.2020).RiseininsecticidaltoxicityduetoneonicotinoidseedtreatmentsIntheU.S.,thetoxicityofinsecticideuseinagriculturehasincreaseddramaticallyoverthepasttwodecades.Researchersfoundthatinsecttoxicload–ametricthatadjuststheamountofinsecticidesusedbytheiracutepotencytohoneybees–hasincreasednine-foldonanoralbasissincejust1997(Douglasetal.2020).Themaindriverofthistrendistheseedindustry’smassivedeploymentofneonicotinoidseedcoatingsontheseedoffieldcrops(e.g.cornandsoybeans)thathadpreviouslynotbeenextensivelytreatedwithinsecticidesofanysort(DouglasandTooker2015).Becauseoftheirextremelyhighpotencyaswellasextentofusage,by2012neonicotinoidsalonecomprised98%oforalinsecttoxicload,equivalentto16billionhoneybeeoralLD50dosespertreatedhectare(Douglasetal.2020).ThemostdramaticincreasesoccurredintheHeartland(121-foldincrease)andtheNorthernGreatPlains(53-foldincrease),wherethemajorityofcornandsoybeans,nearlyall(corn)oraregrown(Ibid.).

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Whileneonicotinoidsaredeployedasfoliarandsoil-appliedsprays,seedtreatmentsemployingimidacloprid,clothianidinorthiamethoxamcompriseroughlythree-fourthsoftotalagriculturaluseofthefiveneonicotinoidcompoundsonaweightbasis.ThisisbasedonEPA’sscreeninglevelusageanalysesforeachofthefive:3millionlbs.seedtreatmentvs.justover1millionlbs.forfoliarandsoil-appliedsprays,annually,thoughthisisasubstantialunderestimatethanksinparttolackofdataonseedtreatmentssince2015.2YetEPAhasenactedlittleifanymitigationforthispredominantuseofneonicotinoids.NeonicotinoidExposureRoutesNeonicotinoiddustfromtreatedseedskillshoneybeesandotherinsectsSeedstreatedwithneonicotinoids(clothianidin,thiamethoxamorimidacloprid)andotherpesticides(oftenfungicides)cansticktogether,causingunevenplantspacing.Talcorsomeotherlubricantisaddedtoseedboxestoreducefrictionandensurethesmoothflowofseedduringplanting.Someportionoftheseedcoatingisabradedintheseedboxandcontaminatesthetalcwithhighlevelsoftheneonicotinoid.Thetalcisexpelledeitherwiththeseedorbehindtheplanterviaexhaustfan(Krupkeetal.2012).Thisseeddust,broadcastacrossthelandscape,hasbeenimplicatedinnumerousbeemortalityeventssince1999inItaly,France,Slovenia,GermanandCanadaaswellastheU.S.:“[i]nallcases,agreatnumberofdeadanddyingbeeswerefoundnearthehiveentrance”(Bonmatinetal.2015).Onestudyexaminedthethreatofneonicotinoid-lacedseeddusttohoneybeesinIndiana,andfoundthatover94%ofhoneybeeforagersintheStateofIndianaareatriskofexposuretovaryinglevelsofneonicotinoidinsecticides,includinginsomecaseslethallevelsduringtheplantingofcorn.Theyalsofoundthatdepositionofneonicotinoidresiduesonnon-targetlandsandwaterwaysoccursonover42%ofthestateofIndiana,andthatriskstopollinatorscouldbedramaticallyreduced,withnoyieldloss,bylimitinguseofseedtreatmentstosituationswheretheyareactuallyneeded(Krupkeetal.2017).EPAhasnotproposedanymitigationtoaddresslethalorsublethalexposuretoneonicotinoid-lacedseeddust.OtherexposureroutesAmajorpathwayofpollinatorexposuretoneonicotinoidsisthepollenandnectarofcropsfromtreatedseed.Inareviewof20studies,Godfrayetal.(2014)estimateaveragemaximumlevelsofneonicotinoidsof1.9ppbinthenectarof6.1ppbinthepollenofseed-treatedcrops,valuesinlinewiththosefoundinanupdatetothatreview(Godfrayetal.2015).WoodandGoulson(2017)reportexpectedresiduesinseveralcrops(corn,sunflower,rape,cotton)ascalculatedby2First,theseedtreatmentfiguresforeachrelevantcropthatcomprisethetotalarelong-termaverages(e.g.2005to2013forthiamethoxam,EPA1/26/16),andtheaveragesunderstateusagebecausetheproportionofcropseed,andinthecaseofcorntherateapplied,haveincreasedsteadilyoverthatperiod(DouglasandTooker2015).Second,theprivatesectorfirmthatEPAreliesuponforseedtreatmentusagedatastoppedcollectingitafter2014;andusageofneonicotinoidswastrendingsteadilyupwardforallmajorcrops(corn,soybeans,cottonandwheat)upuntilthattime,andthankstoinactiononthepartofEPAhasalmostcertainlycontinuedtoincreasesincethen(Hitajetal.2020).

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theEuropeanFoodSafetyAuthoritybasedonoutdoorstudiesandseedtreatmentratesauthorizedintheEuropesnUnion.Maximumexpectedresiduesinpollenrangedupto37ppmincorn(clothianidin);19ppminoilseedrape(clothianidinandthiamethoxam);and4ppminsunflower(imidacloprid).SeeTable1below.Guttationdroplets(smallwaterdropletsexudedbyplants)oftreatedplantscontainfourtofiveordersofmagnitude(10,000to100,000times)higherneonicotinoidconcentrationsthanthosefoundinnector(Girolamietal.2009,WoodandGoulson2017).Whilethepotentialforexposure(pollinatorvisitationofguttationdroplets)isuncertain,ahoneybeewouldonlyneedtoconsume0.005ultoreceiveanLD50dose(WoodandGoulson2017).Thus,eveninfrequentvisitationcouldcauseconsiderableharm.Neonicotinoidsarerelativelypersistentinsoil,andtheplantingofmanyfieldseveryyeartotreatedseeds(e.g.asinthecommoncorn-soybeanintheU.S.,withtreatedseedcomprisingamajorityofeachcrop)ensuresacontinualpresenceinsoil(e.g.Xuetal.2016).Variousstudiesfindsingledigitto50ppbconcentrationsofimidacloprid,clothianidinand/orthiamethoxamincropfields,withdetectionseveninfieldsthathadnotreceivedanytreatmentinthepreviousthreeyears(reviewedinWoodandGoulson2017).EPAdoesnotpaysufficientconsiderationtothisexposurepathway,inpartbecauseitisoflessersignificanceforhoneybees,thesurrogateforterrestrialinvertebratesinEPA’secotoxicityregulatoryscheme.Yetsoilcontactand/oringestionisanimportantexposurepathwayforground-nestingbumblebeesandmanyotherterrestrialinvertebratesthatresideinthesoil.

Source:WoodandGoulson(2017).Neonicotinoidshavealsobeendetectedinthetissuesofoff-fieldwildplants.Forinstance,Krupkeetal.(2012)foundthiamethoxam(upto2.9ppb)andclothianidin(upto9.4ppb)indandelionsnearatreatedcornseedfield,whilePecenkaandLundgren(2015)foundclothianidinintheleavesofmilkweedplantsadjacenttotreatedcornfields.InafieldstudyconductedintheU.K.,Botíasetal.(2015)placedhoneybeecoloniesnearoilseedrapeandwheatfieldsthatoriginatedfromtreatedseed.BasedonpollencollectedinJuneandAugustfromhoneybeeforagersreturningtothehives,97%ofthetotalneonicotinoidspresentinpollenwereofwildflowerorigin,fromplantsgrowinginhedgesalongthefieldmargins.

et al. (2014) reviewed 20 published studies to calculate anarithmetic mean maximum level of 1.9 ppb for nectar and6.1 ppb for pollen in treated crops, in line with the EFSAfindings.

Since 2014, a number of studies have been publishedwhich report neonicotinoid concentrations in the pollen andnectar of neonicotinoid-treated flowering crops. These resultshave been approximately in line with the concentrations re-ported by EFSA and Godfray et al. In oilseed rape treated withthiamethoxam, Botías et al. (2015) found average concentra-tions of 3.26 ng/g of thiamethoxam, 2.27 ng/g of clothianidinand 1.68 ng/g of thiacloprid in the pollen. Oilseed rape nectarcontained similar average concentrations of 3.20 ng/g ofthiamethoxam, 2.18 ng/g of clothianidin and 0.26 ng/g ofthiacloprid. Xu et al. (2016) found average levels ofclothianidin in oilseed rape of 0.6 ng/g. No pollen sampleswere taken. In maize pollen, Stewart et al. (2014) found

average thiamethoxam and clothianidin levels between thelimit of detection (LOD) of 1 to 5.9 ng/g across a range ofseed treatments. Xu et al. (2016) found average clothianidinconcentration of 1.8 ng/g in maize pollen. Additionally,Stewart et al. (2014) found no neonicotinoid residues in soy-bean flowers or cotton nectar.

Several studies published since 2013 have used free flyingbees to experimentally demonstrate that proximity to treatedflowering crops increases their exposure to neonicotinoids(Table 2). Using honeybees, neonicotinoid concentrations inpollen taken from foragers returning to nests placed next tountreated flowering crops ranged from0 to0.24ng/g comparedto pollen from nests next to treated flowering crops whichranged from 0.84 to 13.9 ng/g. There have been fewer studiesofbumblebees, andhence, the samplesize ismuchsmaller,withconcentrations of neonicotinoids in pollen fromuntreated areasranging from <0.1 to <0.3 ng/g compared to 0.4–0.88 ng/g for

Table 1 Summary of expectedresidues in pollen and nectar ofvarious neonicotinoid-treatedflowering crops calculated byEFSA from the review of outdoorfield trials

Crop Pesticide Application rates(g a.s./ha)

Residues in pollen (ng/g) Residues in nectar (ng/g)

Minimum Maximum Minimum Maximum

Oilseed rape Clothianidin 25–80 5.95 19.04 5 16

Sunflower Clothianidin 27 3.29 0.324

Maize Clothianidin 25–125 7.38 36.88 n/a n/aOilseed rape Imidacloprid 10–52.5 1.56 8.19 1.59 8.35

Sunflower Imidacloprid 24–35 3.9 1.9

Maize Imidacloprid 54–268 3.02 15.01 n/a n/aCotton Imidacloprid 75–100 3.45 4.6 3.45 4.6

Oilseed rape Thiamethoxam 8–33.6 4.592 19.29 0.648 2.72

Sunflower Thiamethoxam 16.4–20.8 2.378 3.02 0.59 0.75

Maize Thiamethoxam 63–101 13.419 21.513 n/a n/a

No nectar values are available for maize as this plant does not produce nectar. Blanks are where no minimumvalues were stated

Fig. 2 Number of studiespublished in scientific journals onneonicotinoids in each year.Opencircles, Bneonicotinoid*^; filleddiamonds, Bneonictotinoid* +bee*^; filled circle,Bneonicotinoid* + residue^; opentriangle, Bneonicotinoid* +water^; filled triangle,Bneonicotinoid* + soil^. Datafrom Web of Science

Environ Sci Pollut Res (2017) 24:17285–17325 17287

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Remarkably,directmeasurementsoftheneonicotinoidcontentofpollenandnectarofthesewildflowersshowedconcentrationsofthesameorderasandevengreaterthanthatfoundintreatedcropspollenandnectar.Indeed,othershavemadesimilarfindings.Inareviewofstudiespublishedsince2013,WoodandGoulson(2017)found:

“…averagelevelsofneonicotinoidsinwildplantsrangefrom1.0to7.2ng/ginwholeflowersamples,0.4to13.5ng/ginfoliagesamples,<0.1to1.5ng/ginnectarsamplesand<0.04to14.8ng/ginpollensamples.Duetothelimitednumberofstudiesavailable,itisdifficulttomakeacomparisonwithlevelsindirectlytreatedcropplants.However,theyarebroadlycomparabletothelevelsfoundinthetreatedcropitself.”

Neonicotinoidsarehighlywater-solubleandarealsofrequentlyfoundinwaterbodies,anotheravenueofexposuretotheselong-livedcompounds(Morrisseyetal.2015,Bonmatinetal.2015,WoodandGoulson2017).NeonicotinoidEffectsonPollinatorsAmajorweaknessofEPA’sassessmentisthefailuretoevaluatethesublethaleffectsofneonicotinoidsandtheirinteractionswithotherfactorssuchasdiseaseandpestpressure.ImpactsongrowthandreproductionWhitehornetal.(2012)simulatedexposureofbumblebeecoloniestoconcentrationsofimidaclopridinpollenandsugarwaterrealisticforseedtreatmentuseofthisneonicotinoid,andfoundsignificantlyreducedgrowthrateinthecoloniesandan85%reductionintheproductionofnewqueenscomparedtocontrols.Laycocketal.(2012)foundthatqueenlessmicrocoloniesofworkerbumblebeessubjectedtoarangeofimidaclopriddosesdeliveredinsugarsyrupexhibitedadose-dependentdeclineinfecundity,withrealisticdosesintherangeof1ppbreducingbroodproductionbyathird.Williamsetal.(2015)foundthatexposureofhoneybeequeenstofield-realisticconcentrationsofneonicotinoids(bee-collectedpollensupplementsspikedwith3ppbthiomethoxam+1ppbclothianidin)duringdevelopmentresultedincomprisedovariesandreducedqueensuccess.Tsetkovetal.(2017)quantifiedthedurationandmagnitudeofexposuretoneonicotinoidsoverfourmonthsinCanada’scorn-growingregion,andthenconductedrealisticexperimentsinwhichhoneybeecolonieswereexposedtoclothianidininanartificialpollensupplementwiththeconcentrationtimecoursematchingthatpreviouslyobserved.Theyfoundincreasedworkermortality,declinesinsocialimmunity(reducedhygienicbehavior)andincreasedqueenlessovertime.James(2019)foundthatmonarchadultsfeedafieldrealisticrateofimidaclopridfor22dayssufferednearly80%mortalitybyday22,comparedto20%inuntreatedcontrols.WeakenedimmunityThereisalargeandgrowingliteraturedemonstratingthatneonicotinoidexposureweakenspollinators’defensesagainstdiseasepathogensandpests.Alauxetal.(2010)foundthathoneybeesexposedtoimidaclopridandtheparasiticmicrosporidiaNosemasufferedhighermortalityandenergeticstressthanuntreatedbeesorthoseexposedtoonlyimidacloprid(IMI)orNosema.TheyalsofoundthattheIMI-Nosemagrouphadsignificantlyreducedglucose

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oxidaseactivity,whichenablesbeestosterilizecolonyandbroodfood,andhypothesizethatIMIandNosemasynergizetorenderhoneybeecoloniesmoresusceptibletoinfectionbypathogens.Pettisetal.(2012)exposedhoneybeecoloniesoverthreebroodgenerationstosublethaldosesofimidacloprid,thenchallengedwithNosema,whichproducedsignificantlyincreasedinfectionsversuscontrolsnotexposedtoimidacloprid.

“Thefindingthatindividualbeeswithundetectablelevelsofthetargetpesticide,afterbeingrearedinasub-lethalpesticideenvironmentwithinthecolony,hadhigherNosemainfectionsissignificant.Interactionsbetweenpesticidesandpathogenscouldbeamajorcontributortoincreasedmortalityofhoneybeecolonies,includingcolonycollapsedisorder,andotherpollinatordeclinesworldwide.”

Neonicotinoidexposurehasalsobeenassociatedwithincreasedsusceptibilitytoviraldisease.Forinstance,DiPriscoetal.(2013)foundthatclothianidinnegativelymodulatesNF-xBimmunesignalingininsectsandadverselyaffectshoneybeeantiviraldefensescontrolledbythistranscriptionfactor.ClothianidinenhancesthetranscriptionofageneencodingaproteinthatinhibitsactivationofNF-xB.Imidaclopridwasalsofoundtohavethiseffect.Theantiviralsuppressionledtoproliferationofdwarfwingvirus.

“Collectively,ourdatademonstratethattwoneonicotinoidinsecticides,eachrepresentingoneoftwoalternativestructuretypesinthegroupofnitroguanidines,activelypromoteDWV[dwarfwingvirus]replication.”

ArecentstudyonhoneybeescollectedfromawinterapiaryinFrancetestedtheeffectsofco-exposuretothiamethoxamandthechronicbeeparalysisvirus(CBPV).Theresearchersfoundthatco-exposuredidnotaffectbeesurvivalortheirabilitytometabolizethethiamethoxamtoclothianidin;howevertheyfoundthatco-exposureincreasedCBPVloads,whichreachedlevelsusuallyfoundinovertinfections,andwasassociatedwithdown-regulationofvitellogeninanddorsal-1agenetranscription,bothofwhichareinvolvedinimmunesystempathways.Sanchez-Bayoetal.(2016)reviewadditionalstudiesonthesubjectofneonicotinoidexposureandbeediseases.Thereisalsoevidencethatneonicotinoidsweakenplantdefenses,forinstancetospidermites,bysuppressingtheexpressionofplantdefensecompoundsandalteringthelevelsofphytohormonesinvolvedinplantdefenseincotton,cornandtomato(Szczepaniecetal.2013).OthersublethaleffectsNeonicotinoidexposurehasalsobeenassociatedwithimpairedlearning,memoryandforagingbehaviorsinvariousbeespecies,sublethaleffectsthatarelikelycontributingtobeedeclines(reviewedinWoodandGoulson2017;Godfrayetal.2014,2015).Foroneofmanyexamples,Tosietal.(2017)foundthatanacute,sublethaldoseofthiamethoxam(1.34ng/bee)triggeredexcitationandsignificantlyincreasedflightdurationamongforagers,whilechronicexposurereducedflightduration,distanceandvelocity.

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NeonicotinoidEffectsonOtherInvertebratesDouglasetal.(2015)foundthatslugsfeedingonneonicotinoid-treatedsoybeanseeds/seedlingsaccumulatedneonicotinoidsintheirtissues;andthatgroundbeetlesattackingtheseneonic-lacedslugsexperiencednervoussystemimpairment,withsubstantialmortality.Theyalsoshowedthatneonicotinoidssuppressedslugpredationbygroundbeetles,andwasassociatedwithasignificantyieldlossrelativetoanuntreatedsoybeanfieldcontrol.Similarly,Szczepaniecetal.(2011)foundthatapplicationofimidaclopridtoelmtreescausedanoutbreakofspidermites,aneffectmediatedbyareductioninthedensityofthemites’predatorsduetoimidacloprid-inducedmortality.Suchtritrophicimpactsofneonicotinoidusecouldwellbequitecommon,yetaremissedentirelybyEPA’sregulatoryguidelinetests.Douglasetal.(2015)alsodetectedneonicotinoidconcentrationsof54and279ppbintwoearthwormsfromathiamethoxam-treatedsoybeanfield.Whilenotevidentlyaffectedthemselves,earthwormpredatorsmighttakeupneonicotinoidresidueswiththeirprey,withpotentialadverseeffects.NeonicotinoidimpactsonvertebratesNeonicotinoidsposeasevereacuteriskofmortalitytobirdswhichconsumetreatedseeds.EPAnotesthat:

“Thehighestriskwasidentifiedforsmallsizebirdswhichwouldneedtoconsumelessthanasingletreatedsorghumandwheatseedtoexceedtheacutelevelofconcern,whilewithsmallormediumsizebirdsconsumingcotton,sorghum,andwheatseed,abirdwouldonlyneedtoconsume1-4seeds[two(cotton)orfour(sorghumandwheat)]toexceedtheacutelevelofconcern.”(EPAPIRRDImidacloprid,p.23).

Insecticidessotoxicthatconsumptionofjustoneorseveraltreatedseedsissufficienttokillobviouslyhavenoplaceinagriculture.Birdsmayalsobeatriskthroughconsumptionofneonicotinoid-containingprey,suchasslugsorearthworms.Sublethaleffectsmustalsobeconsidered.Engetal.(2017)foundthatmigratorywhite-crownedsparrowsexposedtosublethaldosesofimidaclopridsufferedsignificantdeclinesinbodyfatandmass,andfailedtoorientproperly.Afollow-upexperimentonthesamespeciesrevealedsimilarimidacloprideffects:reducedfoodconsumption,mass,fatandalteredlikelihoodofdeparturewhenexposedatamigratorystopover(Engetal.2019).ArecentstudyfoundthattheecholocationsystemofInsectivorousbatsmightbeimpairedbyexposuretoimidacloprid(Wuetal.2019).Endocrine-disruptingpotentialofneonicotinoidsEPAhasnotyetmadeanyfindingsregardingtheendocrinedisruptionpotentialofthesefiveneonicotinoids.Beforemakinganydeterminations,EPAshouldconsultindependentstudiesonthesubject.Forinstance,threerecentstudiessuggestimidaclopridisanendocrinedisruptor,withimplicationsforbothhumanhealthandwildlife(Yuanetal.2020,Mikolicetal.2018,PandeyandMohanty2015).

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COSTSANDBENEFITSOFNEONICOTINOIDUSEEPAasusualsconductsa“benefits”ratherthana“cost-benefit”assessmentofneonicotinoids.Examplesofcostsnotaccountedforarethesoybeanyieldreductionsattributabletopredationoftreatedsoybeanseedlingsbyslugs,whosepopulationsincreasethankstoreleasefromcontrolbygroundbeetles,whicharepoisonedwhentheyattempttoattackthem(Douglasetal.2015).Growingresistancetoneonicotinoidsinthripsandotherinsectsispredictable,giventheirprophylacticuse,everyyear,acrosshundredsofmillionsofacresofcropland,andisalreadyleadingtoadramaticincreaseininsecticideuseincotton(Husethetal.2018).EPAfailstoaccountforthefollow-oncostsofthisresistance,bothincreasedexpendituresoninsecticidesandenvironmentalharms,whichareadirectresultoftheAgency’sblanketapprovalsforvirtuallyunlimitedseedtreatmentuseofneonicotinoidinsecticides.EPAalsocounts“benefits”insituationswhereitfailstoconsiderlesschemical-intensiveandmorebeneficialalternatives.Forinstance,abeneficialfungus,Hirsutellacitriformis,naturallyinfestsandkillsthepsyllidvector;evenbetter,thedeadpysllidsremainoncitrusleavesforextendedperiods,spreadingthefungustootherpsyllids(O’Brian2013).AnotherpromisingbiocontrolpredatorisTamarixiaradiata,aparasiticwaspthatspecializesinkillingpsyllids(Lopez2013).Forbothfungusandwasp,pesticideuseforotherpurposesisanobstacletotheireffectiveness.Anotherneonicotinoiduseisforcontroloftheglass-wingedsharpshooter,aninsectthatpiercesplantsandfeedsontheirxylemfluids,butwhichalsovectorsaplantpathogenicbacterium,Xylellafastidiosa,thatinfestsgrapesandothervaluablecropsinCalifornia.Biocontroloptionsalsoexistforthispest,butwilllikelynotbepursueddiligentlyaslongasthereistheeasyoptionofneonicotinoidapplication(Irvinundated).Thisfailuretodevelopbiocontrolsolutionsisaclearcostoftheneonicotinoidregistrations.Ontheotherhand,thepredominantseedtreatmentuseofneonicotinoidsprovidelittleornobenefitintermsofyield.EPAitselfcametothisconclusionforsoybeans(EPA10/15/14),whichwasrecentlyconfirmedbyalonglistofagronomistsfromuniversitiesacrossthecountry(Mourtzinisetal.2019).AstudyinIndianafoundthesame“noyieldbenefit”ofneonicotinoidseedtreatmentsforcorn(Krupkeetal.2017).

OTHERREGULATORSSEEANDACTONRISKSTHATEPADISCOUNTSCanada’sPestManagementRegulatoryAgency(PMRA)–hardlyanenemyofpesticideuse–hasworkedjointlywithEPAonassessingneonicotinoids(EPA1/6/16).OnthebasisofmuchthesameevidenceasEPA,PMRAdecidedtherisksweretoogreat,especiallytoaquaticinvertebrates,andpossiblemitigationmeasuresineffective.Despitedelays,PMRAisstillofficiallycommittedtoaphase-out.In2018,theEuropeanFoodSafetyAuthorityexpandedapre-existingrestrictiononneonicotinoidstocoverallfiledcrops(Stokstad2018).EPAisthusaloneindenyingtheoverwhelmingevidenceofharmcausedbyneonicotinoidinsecticidestopollinatorsandotherwildlife.

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CONCLUSIONEPAisurgedtocanceltheregistrationsofthefiveneonicotinoidinsecticidesdiscussedinthesecomments.Attheveryleast,suspendtheuseofimidacloprid,thiamethoxamandimidaclopridasseedtreatments,particularlyforhighacreagecropslikecornandsoybeans.BillFreese,SciencePolicyAnalystCenterforFoodSafety

ReferencesAlaux,C.,J.L.Brunet,C.Dussaubat,F.Mondet,S.Tchamitchan,M.Cousin,J.Brillard,A.Baldy,L.P.Belzunces,Y.LeConte.2010.InteractionsbetweenNosemamicrosporesandaneonicotinoidweakenhoneybees(Apismellifera).EnvironmentalMicrobiology12(3):774-782.ArnasonR(2013).Noyieldbenefitfromneonicotinoids:scientist.TheWesternProducer,May10,2013.https://www.producer.com/2013/05/no-yield-benefit-from-neonicotinoids-scientist/.BonmatinJMetal.(2015).Environmentalfateandexposure;neonicotinoidsandfipronil.Environ.Sci.Pollut.Res.22:35-67.BotíasC,DavidA,HorwoodJ,Abdul-SadaA,NichollsE,HillE,GoulsonD(2015)Neonicotinoidresiduesinwildflowers,apoten-tialrouteofchronicexposureforbees.EnvironSciTechnol49:12731–12740.BurkeAPetal.(2018).MammalianSusceptibilitytoaNeonicotinoidInsecticideafterFetalandEarlyPostnatalExposure.ScientificReports8:16639.ChenJetal.(2018).Areorganosiliconsurfactantssafeforbeesorhumans?ScienceoftheTotalEnvironment612:415-421.ChenXDetal.(2010).Mixtureeffectsofthenonylphenylpolyethoxylate,R-11andtheinsecticide,imidaclopridonpopulationgrowthrateandotherparametersofthecrustacean,Ceriodaphniadubia.EcotoxicologyandEnvironmentalSafety73:132-137.

13

Coulonetal.(2019).Influenceofchronicexposuretothiamethoxamandchronicbeeparalysisvirusonwinterhoneybees.PLoSOne14(8):e0220703.Cross,A.;Bond,C.;Buhl,K.;Jenkins,J.(2017).PiperonylButoxideGeneralFactSheet;NationalPesticideInformationCenter,OregonStateUniversityExtensionServices.npic.orst.edu/factsheets/pbogen.html.DiPriscoetal.(2013).Neonicotinoidclothianidinadverselyaffectsinsectimmunityandpromotesreplicationofaviralpathogeninhoneybees.PNAS110(46):18466-71.DouglasMRetal.(2020).County-levelanalysisrevealsarapidlyshiftinglandscapeofinsecticidehazardtohoneybees.ScientificReports10:797.DouglasMR&TookerJF(2015)Large-scaledeploymentofseedtreatmentshasdrivenrapidincreaseinuseofneonicotinoidinsecticidesandpreemptivepestmanagementinUSfieldcrops.EnvironmentalScience&Technology49(8):5088-5097.DouglasMR,RohrJR,TookerJF(2015).Neonicotinoidinsecticidetravelsthroughasoilfoodchain,disruptingbiologicalcontrolofnon-targetpestsanddecreasingsoyabeanyield.JApplEcol52:250–260.EngMLetal.(2019).Aneonicotinoidinsecticidereducesfuelinganddelaysmigrationinsongbirds.Science365:1177-80.EngMLetal.(2017).Imidaclopridandchlorpyrifosinsecticidesimpairmigratoryabilityinaseed-eatingsongbird.ScientificReports7:15176.EPA(12/15/17).Acetamiprid:DraftHumanHealthRiskAssessmentforRegistrationReview,DPBarcodeD441937,EPA-HQ-OPP-2012-0329-0025,EPA,December15,2017.EPA(12/5/17).Thiamethoxam:DraftHumanHealthRiskAssessmentforRegistrationReview,DPBarcodeD439309,EPA-HQ-OPP-2011-0581-0096,EPA,December5,2017.EPA(9/12/17).Dinetofuran:HumanHealthDraftRiskAssessmentforRegistrationReview,DPBarcodeD436969,EPA-HQ-OPP-2011-0920-0620,EPA,Sept.12,2017.EPA(9/7/17).Clothianidin:DraftHumanHealthRiskAssessmentinSupportofRegistrationReview,DPBarcodeD439294,EPA-HQ-OPP-2011-0865-0243,EPA9/7/17.EPA(6/22/17).Imidacloprid:HumanHealthDraftRiskAssessmentforRegistrationReview.EPA,June22,2017.EPA(1/16/20).ResponsefromthePesticideRe-evaluationDivisiontoCommentsontheDraftRiskAssessmentsandBenefitsAssessmentsSupportingtheRegistrationReviewofthe

14

Nitroguanidine-substitutedNeonicotinoidInsecticides.EPA-HQ-OPP-2008-0844-1639,EPA,January16,2020.EPA(6/22/17).Imidacloprid:HumanHealthDraftRiskAssessmentforRegistrationReview,DPBarcodeD437947,EPA-HQ-OPP-2008-0844-1235,EPA,June22,2017.EPAImidacloprid(2020).Imidacloprid:ProposedInterimRegistrationReviewDecisionCase,Number7605,EPA,January2020.EPA(2002).DeterminationoftheappropriateFQPAsafetyfactor(s)intoleranceassessment.OfficeofPesticidePrograms,U.S.EnvironmentalProtectionAgency,February22,2002.GodfrayHCJetal.(2015).Arestatementofrecentadvancesinthenaturalscienceevidencebaseconcerningneonicotinoidinsecticidesandinsectpollinators.ProceedingsoftheRoyalSocietyB282:20151821.GodfrayHCJetal.(2014).Arestatementofthenaturalscienceevidencebaseconcerningneonicotinoidinsecticidesandinsectpollinators.ProceedingsoftheRoyalSocietyB281:20140558.HitajCetal.(2020).SowingUncertainty:WhatWeDoandDon’tKnowaboutthePlantingofPesticide-TreatedSeed.BioSciencebiaa019,https://doi.org/10.1093/biosci/biaa019HusethASetal.(2018).InsecticideResistanceSignalsNegativeConsequencesofWidespreadNeonicotinoidUseonMultipleFieldCropsintheU.S.CottonBelt.Environ.Sci.Technol.52(4):2314-2322.IrvinN(undated).Biologicalcontroloftheglassy-wingedsharpshooter(Homalodiscavitripennis)inCalifornia.AppliedBiologicalControlLaboratory,UniversityofCalifornia,Riverside.https://biocontrol.ucr.edu/irvin/gwssbiocontrol.html.JamesDG(2019).ANeonicotinoidInsecticideataRateFoundinNectarReducesLongevitybutNotOogenesisinMonarchButterflies,Danausplexippus(L.).(Lepidoptera:Nymphalidae).Insects10:276.KaraMetal.(2015).Insecticideimidaclopridinfluencescognitivefunctionsandalterslearningperformanceandrelatedgeneexpressioninaratmodel.InternationalJournalofExperimentalPathology96:332-337.KrupkeCHetal.(2017).Plantingofneonicotinoid-treatedmaizeposesrisksforhoneybeesandothernon-targetorganismsoverawideareawithoutconsistentcropyieldbenefit.JournalofAppliedEcology54:1449-58.

15

KrupkeCHetal.(2012).MultipleRoutesofPesticideExposureforHoneyBeesLivingNearAgriculturalFields.PLoSOne7(1):e29268.LaycockI,LenthallKM,BarrattAT,CresswellJE(2012)Effectsofimidacloprid,aneonicotinoidpesticide,onreproductioninworkerbumblebees(Bombusterrestris).Ecotoxicology21:1937–1945.LopezR(2013).Citrusgrowersusepredatorwasptofightdiseasethreat.LosAngelesTimes,August3,2013.https://www.latimes.com/business/la-fi-predator-wasp-20130804-dto-htmlstory.html.LuCetal.(2018).NeonicotinoidResiduesinFruitsandVegetables:AnIntegratedDietaryExposureAssessmentApproach.Environ.Sci.Tech.52(5):3175-84.MaloneyEMetal.(2018).Canchronicexposuretoimidacloprid,clothianidin,andthiamethoxammixturesexertgreaterthanadditivetoxicityinChironomusdilutus?EcotoxicologyandEnvironmentalSafety156:354-365.Mikolić,A.andKaračonji,I.B.(2018).Imidaclopridasreproductivetoxicantandendocrinedisruptor:investigationsinlaboratoryanimals.ArchivesofIndustrialHygieneandToxicology69(2):103-108.MorrisseyCAetal.(2015).Neonicotinoidcontaminationofglobalsurfacewatersandassociatedrisktoaquaticinvertebrates:Areview.EnvironmentInternational74:291-303.MourtzinisSetal.(2019).NeonicotinoidseedtreatmentsofsoybeanprovidenegligiblebenefitstoUSfarmers.ScientificReports9:11207.MullinCA(2015).Effectsof‘inactive’ingredientsonbees.CurrenOpinioninInsectScience10:194-200.O’BrianD(2013).HelpingCitrusGrowersDealWithaNastyInvader.AgriculturalResearch,USDA’sAgriculturalResearchService,January2013.https://agresearchmag.ars.usda.gov/2013/jan/citrus.Pandey,S.P.andMohanty,B.(2015).Theneonicotinoidpesticideimidaclopridandthedithiocarbamatefungicidemancozebdisruptthepituitary–thyroidaxisofawildlifebird.Chemosphere122:227-234.PecenkaJRandLundgrenJG(2015).Non-targeteffectsofclothianidinonmonarchbutterflies.Naturwissenschaften102(3-4):19.Pettis,JSetal(2012).PesticideexposureinhoneybeesresultsinincreasedlevelsofthegutpathogenNosema.Naturwissenschaften99:153-158.

16

Sanchez-BayoandWyckhuys(2019).Worldwidedeclineoftheentomofauna:Areviewofitsdrivers.BiologicalConservation232:8-27.Sánchez-BayoF,GoulsonD,PennacchioF,NazziF,GokaK,DesneuxN(2016).Arebeediseaseslinkedtopesticides?Abriefreview.EnvironInt89-90:7–11Sanchez-BayoandGoka(2014).PesticideResiduesandBees–ARiskAssessment.PLoSOne9(4):e94482.SgolastraFetal.(2016).Synergisticmortalitybetweenaneonicotinoidinsecticideandanergosterol-biosynthesis-inhibitingfungicideinthreebeespecies.Simon-DelsoNetal.(2015).Systemicinsecticides(neonicotinoidsandfipronil):trends,uses,modeofactionandmetabolites.EnvironSciPollutRes22:5-34.Staskal,D.F.;Birnbaum,L.S.;Haws,L.C.Applicationofarelativepotencyfactorapproachintheassessmentofhealthrisksassociatedwithexposuretomixturesofdioxin-likecompounds.Princ.Pract.MixturesToxicol.2010,67−97.StokstadE(2018).EuropeanUnionexpandsbanofthreeneonicotinoidpesticides.Science,April27,2018.https://www.sciencemag.org/news/2018/04/european-union-expands-ban-three-neonicotinoid-pesticides.SzczepaniecAetal.(2013).NeonicotinoidInsecticidesAlterInducedDefensesandIncreaseSusceptibilitytoSpiderMitesinDistantlyRelatedCropPlants.PLoSOne8(5):e2620.SzczepaniecAetal.(2011).NeonicotinoidInsecticideImidaclopridCausesOutbreaksofSpiderMitesonElmTreesinUrbanLandscapes.PLoSOne6(5):e20018.ThompsonHM,FrydaySL,HarkinS,MilnerS.(2014).Potentialimpactsofsynergisminhoneybees(Apismellifera)ofexposuretoneonicotinoidsandsprayedfungicidesincrops.Apidologie45(5):545-553.TomizawaMandCasidaJE(2005).NeonicotinoidInsecticideToxicology:MechanismsofSelectiveAction.Annu.Rev.Pharmacol.Toxicol.45:247-68.TosiSetal.(2017).Acommonneonicotinoidpesticide,thiamethoxam,impairshoneybeeightability.ScientificReports7:1201.TsvetkovNetal.(2017).Chronicexposuretoneonicotinoidsreduceshoneybeehealthnearcorncrops.Science356:1395-97.VanKlinketal.(2020).Meta-analysisrevealsdeclinesinterrestrialbutincreasesinfreshwaterinsectabundances.Science368:417-20.

17

WoodTJandGoulsonD(2017).Theenvironmentalrisksofneonicotinoidpesticides:areviewoftheevidencepost2013.Environ.Sci.Pollut.Res.24:17285-325.Xerces(2016).RecommendationstoProtectPollinatorsfromNeonicotinoids:SuggestionsforPolicySolutions,RiskAssessment,ResearchandMitigation.XercesSocietyforInvertebrateConservation,November2016.https://xerces.org/sites/default/files/2018-05/NeonicsBeeRecommendations_XercesSociety.pdf.XuTetal.(2016).Clothianidininagriculturalsoilsanduptakeintocornpollenandcanolanectaraftermultiyearseedtreatmentapplications.EnvironmentalToxicologyandChemistry35(2):311-321.WhitehornPR,O’ConnorS,WackersFL,GoulsonD(2012)Neonicotinoidpesticidereducesbumblebeecolonygrowthandqueenproduction.Science336:351–352.WilliamsGRetal.(2015).Neonicotinoidpesticidesseverelyaffecthoneybeequeens.ScientificReports5:14621.WuC-Hetal.(2019).Effectsofimidacloprid,aneonicotinoidinsecticide,ontheecholocationsystemofinsectivorousbats.PesticideBiochemistryandPhysiology163:94-101.Yuan,X.,Shen,J.,Zhang,X.,Tu,W.,Fu,Z.andJin,Y.(2020).Imidaclopriddisruptstheendocrinesystembyinteractingwithandrogenreceptorinmalemice.ScienceofTheTotalEnvironment708:135163.ZhangQetal.(2019).Dietaryriskofneonicotinoidinsecticidesthroughfruitandvegetableconsumptioninschool-agechildren.EnvironmentInternational126:672-681.Zhuetal.(2017).Synergistictoxicityandphysiologicalimpactofimidaclopridaloneandbinarymixtureswithsevenrepresentativepesticidesonhoneybee(Apismellifera).PLoSOne12(5):e0176837.