Description of immatures and mating behavior of Liogenys bidenticeps Moser, 1919 (Coleoptera: Melolonthidae: Melolonthinae)

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REVISTA

BRASILEIRA

DE

Entomologia

AJournalonInsectDiversityandEvolution w w w . r b e n t o m o l o g i a . c o m

Systematics,

Morphology

and

Biogeography

Description

of

immatures

and

mating

behavior

of

Liogenys

bidenticeps

Moser,

1919

(Coleoptera:

Melolonthidae:

Melolonthinae)

Sérgio

Roberto

Rodrigues

a,∗

_,

_Juares

_Fuhrmann

b

_,

_Elias

_Soares

_Gomes

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_Ricardo

_Aparecido

_Amaro

a

a_Universidade_Estadual_de_Mato_Grosso_do_Sul,_{Cassilândia,}_MS,_Brazil b_Universidade_de_São_Paulo,_Museu_de_Zoologia,_São_Paulo,_SP,_Brazil c_Universidade_Federal_da_Grande_Dourados,_Dourados,_MS,_Brazil

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t

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c

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e

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Articlehistory:

Received4April2017 Accepted18July2017 Availableonline2August2017 AssociateEditor:MarcelaMonné

Keywords: Diplotaxini Rhizophagousinsect Scarabaeoidea Sexualbehavior Whitegrub

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b

s

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DescriptionofimmaturesandmatingbehaviorofLiogenysbidenticepsMoser,1919(Coleoptera: Melolon-thidae:Melolonthinae).SomespeciesofMelolonthinaeareassociatedwithseveralspeciesofcropped plants,withlarvaeconsumingrootsand,insomecases,areconsideredascroppests.Insomeagricultural regionsofBrazil,larvaeofL.bidenticepsarefoundassociatedwithcultivatedplants,andlittle informa-tionisavailableaboutthistaxon.Thisstudy,aimingatexpandingtheknowledgeaboutthemorphology andbehaviorofthisspecies,providesthedescriptionofimmaturesandmatingbehaviorofadults.The studieswereconductedattheexperimentalfarmoftheUniversidadeEstadualdeMatoGrossodoSulin Aquidauana,MatoGrossodoSulstate,Brazil,andtheadultswerecollectedwithlighttrapandraised inthelaboratory.Matingbehaviorwasdocumentedonvideobothinthefieldandunderlaboratory conditions.Descriptionsandillustrationsofthethirdinstarlarvaandpupaarepresented.Adultshave crepuscularflightactivityandtheircopulationlastsanaverageof20.25min,occurringfrom19:00to 22:00h.Onsomeoccasions,femalesdidnotacceptmalesforcopulation,indicatinganactiveselectionof malesbyfemales.FieldobservationsdemonstratedthatadultsfeedonBrazilianpepperleaves(Schinus terebinthifolius,Anacardiaceae)andcashewflowers(Anacardiumoccidentale,Anacardiaceae),wheremale andfemalemeeteachotherandcopulationoccurs.

).

InBrazil,somespeciesofMelolonthidae(sensuChermanand Morón, 2014)occurin agriculturalareasassociated withcrops, usingthemashostplantsandcausingdamageonthem.Larvaeof theseinsectsusuallyfeedontherootsystem,resultinginsymptoms suchasrootreduction,wilting,yellowing,andplantdeath(Oliveira etal.,2007,2008;Coutinhoetal.,2011).Sincethe1980s,larvaeof somephytophagousMelolonthinaehave causeddamageto sev-eralcropsatdifferentBrazilianregions.AnexampleisPhyllophaga cuyabana(Moser,1918)(Melolonthini),whichisthemainpestof soybean(Glycinemax(L.)Merr.,Fabaceae)inParanástate(Oliveira andGarcia,2003).InRioGrandedoSulstate,phytophagouslarvae areabundantinwintercrops,beingDiloboderusabderus(Sturm, 1826)(Dynastinae,Pentodontini)themainspeciescausingdamage onthem(SilvaandCosta,2002).

Studies carried out in Mato Grosso do Sul (MS) state, havedemonstratedtheimportanceofMelolonthidaespeciesfor

∗ Correspondingauthor.

E-mail:[email protected](S.R.Rodrigues).

agribusiness.Coutinhoetal.(2011)foundlarvaeofCyclocephala verticalisBurmeister,1847(Dynastinae,Cyclocephalini),C.forsteri Endrödi, 1963, Liogenys fusca Blanchard, 1851 (Melolonthinae, Diplotaxini), and Anomonyxsp. (Melolonthinae, Macrodactylini) associatedwithsugarcane(Saccharumspp.Poaceae)rootsystem. Indifferentsuccessionsystemsofseveralcrops,Rodriguesetal. (2011)foundlarvaeofL.fusca,L.bidenticepsMoser,1919,C.forsteri, C.verticalis,GeniatesborelliCamerano,1894(Rutelinae,Geniatini), Anomalatestaceipennis(Blanchard,1856)(Rutelinae,Anomalini), andA.inconstans(Burmeister,1844)causingdamagetosoybean andcorn(ZeamaysL.,Poaceae).SantosandÁvila(2007)recorded, inthemunicipalityofMaracaju(MS),larvaeofC.forsterifeedingon soybeanroots.SantosandÁvila(2009)consideredlarvaeofL. sutu-ralis(Blanchard,1851)aspotentialpestsforcorn,wheat(Triticum aestivumL.,Poaceae), oats(AvenastrigosaSchreb.,Poaceae),and soybean.

ThegenusLiogenysGuérin-Méneville,1831includes77species (EvansandSmith,2009;Chermanetal.,2016),ofwhich28occur inBrazil.InMatoGrossodoSulstate,L.bidenticeps,L.fusca,andL. suturalisarewidelysampledspecies(Rodriguesetal.,2008,2011; SantosandÁvila,2009).

http://dx.doi.org/10.1016/j.rbe.2017.07.006

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rye(SecalecerealeL.,Poaceae),soybean,andcorn(Chermanetal., 2011;Rodriguesetal.,2011).Biologicalaspectsofthisspeciesare known(Rodriguesetal.,2014a):theembryonicperiodlastsfor17.2 days,thelarvaofﬁrst,second,andthirdinstars(notinprepupae) lastfor34.8,35.3,and97.0days,respectively,pre-pupaestagelasts for99.6days,andpupalastsfor21.8days;thebiologicalcycleis completedin301.3days.

About the larvae morphology of Liogenys, the shape of the palidia(c.f.Böving,1936)isknownfor L.bidenticeps,L.fusca,L. obesaBurmeister,1855,andL.sinuaticepsMoser,1918(Cherman etal.,2011),and immaturesof L.fusca wererecentlydescribed (Rodriguesetal.,2016).

GiventhecommonoccurrenceofL.bidenticepsinseveral agri-cultural regions of Brazil, its association with cropped plants, combinedwiththelittleinformationaboutthisspecies,thisstudy aims to expand the taxonomic and behavioral knowledge by describingtheimmaturesmorphologyandthecopulatorybehavior ofadults.

Materialandmethods

AdultL. bidenticepswerecollectedat theexperimentalfarm of the Universidade Estadual de Mato Grosso do Sul (UEMS) in Aquidauana,MS,Brazil,fromSeptembertoDecember2010usinga LuizdeQueirozlighttrapmodel(SilveiraNetoandSilveira,1969).In thelaboratory,maleandfemalecouplesweremaintainedin sep-arate4-LplasticcontainerswithsoilandseedlingsofBrachiaria decumbensStapf(Poaceae).Thesecontainerswerecoveredwith voilefabrictopreventinsectsfromleaving.

Containerswereinspecteddailyinordertoseparateeggsand removedeadinsects. EggsweremaintainedinPetridishes con-tainingsievedandmoistenedsoil,andplacedinanair-conditioned chamber(26_±2◦Cand scotophase).Petridishes wereobserved attwo-dayintervalsandnewlyhatchedlarvaeweretransferred and individualizedin 500-mL plastic containerscontaining soil andB.decumbens(26±2◦Cand12hphotophase)(rearingmethod accordingtoRodriguesetal.,2011).

Thirdinstarlarvaeandpupaewerekilledinboilingwaterand preservedin70%alcohol.TheterminologyfollowsBöving(1936) andthetermshelus(toothorfixedand rigidcuticularprocess) andphoba(agroupofflexiblefixedcuticularprocesses)wereused forbothepi-andhypopharynx.Theepipharynxareasubdivisions (coryphe,haptomerus,paria,pedium,andhaptolachus)are empha-sizedinitalictomakeiteasiertofind.Illustrationswereproduced usingalightchambercoupledtoaMoticstereomicroscope,Zeiss StemiSV6stereomicroscope,ZeissAxioscopmicroscope,orNikon E200microscope.MouthpartsweretreatedwithHoyer’s liquid (JohnsonandTriplehorn,2005)andmountedonslides.Alladults andapercentageofimmaturesofL.bidenticepsweredepositedin theUEMSentomologicalcollection;whiletheotherportionofthe immaturessampleswasdepositedinthecollectionoftheMuseu deZoologiadaUniversidadedeSãoPaulo,SãoPaulo,SãoPaulostate, Brazil(MZSP).ThesoftwareAdobePhotoshopCS6wasusedfor imageprocessinganddrawingtheboards.

Theproposedidentiﬁcationkeyincludedhereinisa modiﬁca-tionofthekeysofRitcher(1966)andChermanetal.(2011),and usesdataprovidedbyRamirez-SalinasandCastro-Ramirez(2015) andRodriguesetal.(2016).

Forthebehavioralstudyunderlaboratoryconditions,several specimens(females andmales) weremaintainedin18 and 30-Lplasticcontainers,with5-cmsoillayerandwereclosedwitha voilefabric.Theadultcouples(70couplesintotal)wereobserved tostudythecopulationprocess,withmethodologyadaptedfrom Facundoetal.(1999).Observationswerecarriedoutduringthe

ditions.Observations were madeon trees and shrubs nearthe laboratory. The specimen behavior was record documented by usingaCanondigitalcameramodelSX160IS.

Results

LiogenysbidenticepsMoser,1919

Thirdinstar(Figs.1–38).Length:17.3mm(15–18mm)(Fig.1). Head(Fig.2),width2.2–2.6mm;epicranialsutureslightlydistinct intheposteriorhalf;stemmataabsent.Eachheadside(Figs.2,3) with4dorsoepicranialsetae(des);2lateroepicranialsetae(les); 3anteroepicranialsetae(aes);9–10ventroepicranialsetae(ves);4 posterofrontalsetae(pfs);3lateralofrontal(orexternofrontal)setae intheanteriorangles(lfs);2anterofrontalsetae(afs);1 anterocli-pealseta(acs);2lateroclipealsetae(lcs);2–3posterolabralsetae (pls);4laterolabralsetae(lls);1mediolabralseta(mls);2 antero-labralsetae(als).Cranium,clypeus,andlabrum(Fig.9)withmany sensilla.

Antennifercylindrical,withabout5sensilla.Antennawith4 antennomeres(Figs.4–8):Ishort(length/width=2),with1dorsal and1ventralsensillum;IIlong(l/w=3.3–3.5),with2dorsalsetae, 2dorsalsensilla,1externoproximalsensillum,1externodistal sen-sillum,3 ventralsensilla; IIIshort(l/w=2.3–2.4), with3 dorsal sensilla,3ventralsensilla,1externodistalsensillum,2internodistal sensilla,andwithaventrodistalprocessbearingadorsalsensorial spot,and3dorsalsensilla;IVshort(l/w=2.2–2.4),with1ventral sensillum,2externalsensilla,1internalsensillum,1dorsal senso-rialspot,and2ventralsensorialspots;distalsensorialareawith7 sensilla.

Epipharynx (Figs. 10–12). Corypha: epizygum indistinct; clithrumabsent.Haptomerum:zygumasacross-bar;with5heli, 2spine-likemarginalsetaeoneachside,and9sensilla.Paria:right acropariawith17–19setae,leftacropariawith15setae;each acan-topariawith11–14setae;gymnopariawelldeﬁnedandwithsome sensilla;rightchaetopariawith68–77setae,leftchaetopariawith 47–51setae;plegmatiapresent,proplegmatiaabsent;each side withlongphobae;dexiotormalongerthanlaeotorma;laeotorma with short pterotorma, apotorma and epitorma inconspicuous. Pediumlongerthanwide.Haptolachus:eachsideofcrepiswith3 sensilla;nesiuminternumtubercle-likeandwith4sensilla;nesium externumtabulate;eachsidewithlongphobaenotcontiguouswith pariaphobae;medialareawithsomeminutephobae,lateralarea withsomeminutetubercleandsensilla.Theposteriorpre-oralarea withapairof3sensilla.

Mandible(Figs.13–18).Incisorwith3teeth,thetwoproximal slightlydistinctandseparatedfromeachotherbyasmallgroove. Thedorsalareawith1seta and2sensilla;ventroproximal area witharugousstridulatoryarea;medioexternalareawithaseta. Rightscrobe (externoproximalarea)with4–5setae; leftscrobe with8–12setae.Ventralprocesses welldeveloped.Rightmolar witharowof12 dorsoproximalsetae;with4chisel-liketeeth; well-developedbrustia.Leftmolarwitharowof5dorsoproximal setae;withananteriorsemicircularchisel-liketooth,a ventrome-dialsmalltooth,aciaabsent,andanacutelargecalx.

Maxillae(Figs.19–21).Galeaandlaciniaseparatedbysuture. Galeawithanuncusandarowof6tooth-likeinternoventralsetae; laciniawith3unci;internodorsalareaofmalawitharowof7dorsal tooth-likesetae.Stipewithstridulatoryareabearing12–13acute teeth.Palpwith4palpomers:Iwithanexternalseta;IIwitha ven-troproximalsensillum;IIIwithanexternalseta,aventralseta,and2 ventralsensilla;IVwithaninternodistalsensillum,distalsensorial areawith16–18sensilla.

Hypopharynx(Figs.11,12,20)withasymmetricalsclerite,right lateralwith5setae,leftwith8setae;left,right,andposteriorareas ofscleritewithprominentphoba;posteriorareawith5sensilla.

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Figs.1–8.Liogenysbidenticeps,thirdinstarlarva;1,habitus;2,head;3,chaetotaxyofcraniumandclypeus;4−8,antennae;4,dorsal(antennomereIVdetached);5,internal; 6,external;7,antennomereII,ventral;8,antennomereIV,ventral.Scale:1−3,0.5mm;4−8,0.25mm.

Labium(Figs.11,12,20,21).Eachsideofsubmentumwitha longsetaandsensillum;mentumwithtransversalsclerite,each sideofscleritewith4lateralsetaeandamedialseta;prementum withabout15anteriorsetae;ligulawith5heli,4medialsensilla, asmallmedialtubercle,10–12lateralthinsetae,and14medial tooth-likesetae.Palpwithtwopalpomeres:Iwith1dorsalseta and1smallventroproximalseta;IIwith1externodistalsensillum, distalsensoryareawith10sensilla.

Thorax.Pro-,meso-andmetanotumwith3lobeseach(Fig.1). Legs(Figs.22–27).Protibiawithtwoparallelrowsof5ventralthick setae,eachsetainsertedinashortprocess;meso-andmetatibia with2pairsofthickventralsetae,eachsetainsertedinanacute process;tarsunguluswith2lateroventralsetae,andwithan acumi-nateapex;protarsunguluslongerthanmeso-,meso-longerthan themeta-.Thoracicspiracle(Fig.28)withabout8perforationsin thelongitudinalandventralradii,and12perforationsinthe dor-salradius,perforations oblongand moreorless regular;length 0.41mm,width0.29mm;bullawiderthanthedistancesbetween respiratoryplatearms.

Abdomen.With10segments;I–VIIIwith3dorsallobes,IX–X withoutdorsaldivisions. Spiracles(Figs.29–36)I–VIIsimilarto

eachother,length0.4mm,width0.3mm,andwith9–12 perfora-tionsinallradii(dorsal,longitudinal,ventral);VIIIsmallerthanthe others,length0.3mm,width0.25mm,andwith7–5perforations inallradii.Eachsideoftheraster(Figs.37,38)with:tegillumwith 27–28spine-likesetae,ofwhich22arepreseptularsetae(anterior tothepalidia);barbulaindistinct;palidiumwith5–7tooth-like setae,ofwhichthe2–3anteriorsetaearesmallandtheother3–4 posteriorsetaearelong.SegmentX(Fig.38)withaY-shapedanal opening,eachlateroventralanallobewith18–21setae,dorsalanal lobewith57setae.

Remarks.Cherman et al. (2011) characterizedthe palidiaof L.bidenticeps,L.fusca,L.obesa,andL.sinuaticeps,in additionto providethefollowingdiagnosisforthegenus[addendumhereby noted]:lastantennomerewitha[dorsal]sensorialspot,mandibles withoutaventralstridulatory[striated]area,palidiaobliqueand anteriorlyconvergent[ortransverse(e.g.L.obesa)],analopening Y-shaped.Itisimportanttonotethatthemandiblespresentan analogousgranularstridulatoryareaevenlackingastriated stridu-latory area. Mandibles with a ventral stridulatory area formed byminutespine-likegranulation(similartothatornamentation illustratedinFigs.13,14,17and18)andtheabsenceofastriated

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Figs.9–12.Liogenysbidenticeps,thirdinstarlarva;9,labrum;10,epipharynx;11–12,cibarium(right,left).Scale:0.5mm.

stridulatoryareaarecharacteristicinlarvaeofScarabaeinaeand Melolonthinae (Hayes, 1930; Schiödte, 1874). Böving (1936) described the mandible of Plectrisaliena Chapin, 1934 (Macro-dactylini)as “having the stridulating area completely lacking.” Larvae of two undetermined species of Plectris (MZSP) were observedinthisstudyandbothpresentedmandibleswith granu-larstridulatoryareas.Itispossiblethatthemelolonthinemandible descriptionsbeing“withoutastridulatoryarea”(e.g.Böving,1936; Chermanetal.,2011;Ramirez-SalinasandCastro-Ramirez,2015) arebasedonlyontheabsenceofastriatedarea(usuallypresentin

Cetoniidae,Dynastinae,andRutelinae;andcharacterizedbyseries ofparallelandtransversalcostulationorstriation).

OtherspeciesofDiplotaxiniwithknownlarvaeareDiplotaxis puberea(Bates,1887)(descriptionbyRamirez-Salinasand Castro-Ramirez,2015);andL.fusca(descriptionbyRodriguesetal.,2016). Seeidentiﬁcationkeyfordiagnosis.

Examinedmaterial.BRAZIL.MatoGrossodoSul;Aquidauana, rearinginthelaboratoryG.A.L.Nogueira(collector),11thirdinstar larvaepreservedon23.I.2011(UEMS),7thirdinstarlarvae pre-servedon06.II.2011(MZSP).

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KeytothirdinstarlarvaeofknownDiplotaxini

1–Proplegmatiapresentorabsent;palidialongitudinalandparallel(atleastintheanteriorhalf),orformingatransversalorsemicircularrowofsimilarlengthsetae,or somewhatoblong-fusiform(i.e.anterior-andporteriorlyconvergent),orposteriorlyconvergent;V-orY-shapedanalopening;ifpalidiaobliqueandanteriorlyconvergent andtheanalopeningisY-shaped,thenproplegmatiapresent...MelolonthinaeotherthanDiplotaxini 1–Proplegmatiaabsent;palidiaobliqueandanteriorlyconvergent,ortransverseandwithlateralpaliatleasttwicelongerthanmedialone;Y-shapedanalopening... Diplotaxini...2

2–Palidiawithlateralpaliaslongasmedialones(Neartic)...Diplotaxispuberea 2_–_Palidia_with_lateral_pali_at_least_twice_longer_than_medial_ones_{(Neotropical)}_._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._Liogenys...3

3–Palidiatransverse...L.obesa 3_–_Palidia_oblique_and_{anteromedially}_conversing_._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._.₄

4–Tegillawithsomemedialtegitesalmostaslongandlargeaslongerpali...L.sinuaticeps 4–Alltegitesshorterandslenderthanthelongerpali...5 5–Eachsideofthefronswith3setae;antennomereIIwithadorsalseta...L.fusca 5_–_Each_side_of_the_frons_with₂_setae;_antennomere_II_with₂_dorsal_setae_._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._L._bidenticeps

Pupa(Figs.39–42)

Body(Figs.39–41)whitish,glabrous;length10.4–10.8mm; tho-raxwidth5.4–5.6mm.

Head (Fig. 42). Vertex hidden under pronotum from dorsal view.Epistomalsutureindistinct.Canthussmall.Labrumlongand transversal.Maxillarypalpsprominent.Labiumﬂat.Antennawith threedeﬁnedregions:scape-pedicel,funiculus,andclava.

Thorax.Pronotumwiderthanlong,greaterwidthatthe pos-terior margin, lateral margins rouded. Prosternumwith visible posterior process between pro- and mesocoxae; precoxal area unhiddenbytheheadinventralview.Mesonotumshorterthan pro- and metanotum. Elytra curved ventrally around the body

andwithgrooves.Pro-,meso-andmetacoxacontiguous; mesofe-murspurs tubercle-like,andspursof themetafemurindistinct; mesofemur-tibia partially hidden under the wings in ventral view; protibia with three external teeth. Mesothoracic spiracle presentinacavitybetweenthepronotum,elytron,andanterior leg.

Abdomen. Dioneiform organs absent; tergites I–VI with transversalcarina.AbdominalspiraclesI–VIIIwelldeveloped,with peritreme and slightly prominent; I hidden under the wings. Femaleterminalia.Tergite IXwithacuteurogomphi;sterniteIX withgenitalampullaformedbytwosmalltubercles;tergiteX ven-trallyexposed.

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Figs.19–21.Liogenysbidenticeps,thirdinstarlarva;19,maxilla,internal;20,maxilla,hypopharynx,ligula,dorsal;21,maxilla,labium,ventral.Scale:0.5mm.

Examinedmaterial.BRAZIL;MatoGrossodoSul;Aquidauana, materialrearedinlaboratory,2.VIII.2011,G.A.L.Nogueira (collec-tor),2femalepupae(MZSP),2femalepupae(UEMS).

Remarks.ThepupaofL.fuscawasdescribedbyRodriguesetal. (2016).PupaeofL.fuscaandL.bidenticepscanbedifferentiatedby thesinuosityofthetransversalcarinaontergiteVI.L.fuscahasa deeplysinuouscarina,whileL.bidenticepshasaweaklysinuous carina,almoststraight.Malepuparemainsunknown.

Matingbehaviorinlaboratory

Duringtheday,adults remainedshelteredundertheground (n=140).Atdusk,theyprojectasmallportionoftheclypeusnear thesoilsurfaceandremainanaverageof15.65±1.93(2–30)min. Subsequently,theseinsectsleavethesoilcompletelyandcarryout theﬂightfor15.15_±2.07(12–20)min,onaverage.Afterﬂying,they landandremain motionlessorslightly moving.From70 adults paired,20couplesdidnotpresentstagesbehaviorduringcopula,

50couplespresentedseveralsequencesrelatedtocopulabehavior (Fig.43).

Pre-copula.Maleﬁndsthefemaleandtouchesitspygidiumor theposteriorpartofelytrawiththeforelegs(n=42)ortouches thefemalelaterally(n=8).Inbothsituations,theantennaekept movingwithlamellaeopen.

Afterthesetouches,maleclimbonthefemales.Inseveral rep-etitions(n=14),thefemaledidnotacceptthemaleforcopula.In thesecases,thefemalemovestheelytraandwalksawayuntilthe maledetaches(n=12).Insomecases(n=2),themaleexposedthe aedeagusbutwereunabletointroduceittothefemale.Thus,the maleretractedtheaedeagus,walkedonthefemale,touchedits clypeuswiththeforetarsiandantennae,andreturntotheﬁrst copulationposition,butwithoutsuccess.Thisprocesslastedabout 30seconds. Subsequently,themale leavesthefemale.However, severalsuccessesof thecopula(n=24)wereobserved.Inthese cases,females remainedmotionlessandacceptedthemalesfor copulation,orthefemaleswalkedalittlebutacceptedthemalefor copulation(n=12).Whenfemalesacceptedamaleforcopulation,

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22 23 26 25 24 27 28 29 30 31 32 33 34 35 36

Figs.22–36. Liogenysbidenticeps,thirdinstarlarva;22−24,anterior,medial,andposteriorlegs,external;25−27,pro-,meso-,andmetatarsungulus,dorsal;28,mesothoracic spiracle;29−36,abdominalspiraclesI−VIII.Scale:22−24,1mm;25−28,0.5mm;29−36,0.1mm.

themaleclimbsthefemale,bendingitsbodytoinserttheaedeagus (n=36).

Mating. The mating process lasted on average 20.25±1.59 (9–30)minandoccurredbetween19:00and22:00h.After copula-tion,themaleretractstheaedeagus.However,inmostcases,male remainedonthefemalefor60.45(18–150)min.Thiswouldbethe guardingbehaviorpresentedbythemales.Afterthisbehavior,male andfemaledetach.

Matingbehaviorintheﬁeld

FieldobservationstoverifythatadultsfeedonBrazilian pep-per leaﬂets (Schinus terebinthifolius Raddi1820, Anacardiaceae) (n=286)andcashewﬂowers(AnacardiumoccidentaleL., Anacar-diaceae)(n=60).From18:00,inbothplants,severaladultswere observedinitiallyfeeding,andthencouplingandmating(Fig.44A, B).Activitiesontheplantswereobserveduntil23:00h.

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Figs.39–42.Liogenysbidenticeps,femalepupa;39−41,habitus(dorsal,ventral,lateral);42,head,frontal.Scale:1mm.

In the field, mating process last an average of 22.30±2.56 (13–35)min(n=45).Evenduringcopulation,femalescontinueto feedonBrazilianpepperleaves(n=30)orcashewflowers(n=15). Femalesincopulationcanwalkontheleavesorbranchesofplants. Whenthe copulation process is finished, males remain onthe females,whichoftenwalkandfeedevenwithmalesonthem. Dur-ingcopulation,normallyasecondmalemayapproachandremains onthecouple(n=10)(Fig.44C),orwalksonthem,andthenmoves away(n=20)(Fig.44D).

Inenvironmentswithartiﬁciallight,severaladultsperformeda ﬂightnearthelampsatdusk,andmanyofthemlandorfall.Inthese cases,malesquicklylocatethefemalesandstartthecopulation (n=80).Thus,nearthelightsources,evenintheabsenceoffood sources,adultscopulated.

Discussion

AdultsofLiogenysbidenticepsremainhiddenundertheground during the day and at the beginning of the dusk begin ﬂying activities.SimilarbehaviorwasobservedforadultsofAnomala tes-taceipennisbyRodriguesetal.(2014b).

Adultswereobservedmatingfrom19:00to22:00hinthe labo-ratoryanduntil23:00underﬁeldconditions.AccordingtoMartínez etal.(2000),inanindeterminatespeciesofLeucothyreus(Rutelinae, Geniatini),copulationoccursbetween21:00and1:00h,coinciding withthetimeofgreatestoccurrenceofadultsintheﬁeld.

Matingprocess in adults of L. bidenticeps lasted on average 20.25mininthelaboratoryand22.30minunderﬁeldconditions.In previousstudiescarriedoutbyRodriguesetal.(2014a)L. bidenti-cepsmatingprocesslastedonaverage19.32minunderlaboratory conditions.Thedurationof thematingprocessinadults oftwo otherLiogenysspeciesstudied:copulationprocessinL.suturalis lastsonaverage9.8min(SantosandÁvila,2009)whileinL.fusca lastsonaverage25min(Rodriguesetal.,2008).

Inlaboratorystudies,despitethecouplesweremaintained iso-lated, meaning that there were no other males attempting to copulate with the same female, guard behavior was observed in males. In ﬁeld conditions, males remained on females after copulation,probablytopreventothermalesfromattemptingto copulatewiththefemale.Thisbehaviorprobablyhasan impor-tanceregardingtheadequatespermreceptionbythefemale.In adultsofL.bidenticeps,guardbehaviorwasregisteredbyRodrigues

(9)

Male and female n=70

70

Male and female project their clypeus near the soil surface

Male approaches from the anterior part of female 70

Emerge from soil and fly 50

Land and from couples

42

50

Male climbs female Male approaches from the

posterior part of female

24

20

Walk and feed Land and do not form couples

12 14

14 Female remains

motionless and accept the male

Male moves the abdomen and exposes the aedeagus 36

36

Male curves the abdomen and introduces the

aedeagus

Copulation finishes and male retracts the aedeagus

Male remains on female, then detaches, and walks around or buries

in soil

Female walk a little and accept the male

Female walks away, moves the elytra, and detaches from the male

Copulation does not occur 8

Fig.43.MatingbehaviorethogramforLiogenysbidenticeps.

etal.(2014a),andmalescouldstayforupto4hoursonfemalesafter thecopulationhasﬁnished.AccordingtoRodriguesetal.(2008), somemalesofL.fuscaremainonfemalesinpost-copulationguard behaviorforupto40min.

Anactivefemaleselectionofmaleswasobserved.Similar behav-iorwasobservedforadultsofA.testaecipennisbyRodriguesetal. (2014b).

TheplantspeciesSchinusterebinthifoliusandAnacardium occi-dentalewereusedasfoodsourcesoffeedbyadultsofL.bidenticeps andalsoasamatingsubstrate.AccordingtoPottandPott(1994), S.terebinthifoliusisacommonplantinareasoftheBrazilian Cer-radoandPantanal.Thus,thisplantspeciescanbeanimportantfood sourceforadultsofL.bidenticeps.

Thereare records of differentplant species used as feeding sourcesandmatingsubstratesamongstspeciesofMelolonthidae. AccordingtoRodriguesetal.(2014b),adults ofA.testaceipennis useﬂowers ofoiti (Licaniatomentosa Benth,Chrysobalanaceae) and cordia (Cordia glabrata Martius, Boraginaceae) for feeding and matingsubstrate. Adults ofL. fusca wereobserved feeding and copulatingbetween19:30 and21:00honleavesofaroeira trees(MyracrodruonurundeuvaFr. All.,Anacardiaceae),Brazilian pepper,kingwood(AstroniumfraxinifoliumSchott,Anacardiaceae), andcashewinﬂorescences(Rodriguesetal.,2016).Accordingto Martínezetal.(2013),adultsofLeucothyreusfemoratusBurmeister, 1844,feedandmateonleavesofthepalmtreeElaeisguineenses Jacq.(Arecaceae).

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C

D

Fig.44. MatingbehaviorofLiogenysbidenticepsonleavesofSchinusterebinthifolius(Anacardiaceae);A–B,pairscopulating;C–D,amalecompetitornexttothepaircopulating.

Conﬂictsofinterest

Theauthorsdeclarenoconﬂictsofinterest.

Acknowledgements

This study was supported by the National Council for Sci-entific and Technological Development (CNPq) (Process No. 552377/2011-2).S.R.RodrigueswassupportedbyCNPq(Process No.305260/2014-6).TheauthorswishtothanktheFundaçãode ApoioaoDesenvolvimentodoEnsino,CiênciaeTecnologiadoEstado deMatoGrossodoSul(FUNDECT)forthefinancialsupport.

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