©EntomologicaFennica.31May2011 Description of the first larval instar of Broscus crassimargo Wollaston, 1865 (Carabidae: Broscini) and notes about the presence of the species in the mesovoid shallow substratum of La Gomera (Canary Islands, Spain) JoséD.Gilgado,HeribertoLópez,PedroOromí&VicenteM.Ortuño Gilgado,J.D.,López,H.,Oromí,P.&Ortuño,V.M.2011:Descriptionofthe firstlarvalinstarofBroscuscrassimargoWollaston,1865(Carabidae:Broscini) andnotesaboutthepresenceofthespeciesinthemesovoidshallowsubstratum ofLaGomera(CanaryIslands,Spain).—Entomol.Fennica22:45–55. ThefirstlarvalinstarofthegroundbeetleBroscuscrassimargoWollaston,1865 endemictoLaGomera(CanaryIslands,Spain)isdescribed.Thisisthefirstcom- prehensivestudyoftheprimarychaetotaxyofthethreetagmataevercarriedout inlarvaeofBroscini,beingalsoaccompaniedbyadetailediconography.Theim- plicationsoftheresultsofthischaetotaxyanalysisarediscussedinrelationtothe possibleoriginofBrosciniwithinCarabidae.Commentsontheecologicaldeter- minants for its remarkable presence in the mesovoid shallow substratum are given,analysingthedifferencesbetweenLaGomeraandotherCanaryislands wheresamplingsinthesamesubterraneanhabitathavebeencarriedout. J. D. Gilgado (corresponding author) & V. M. Ortuño, Departamento de ZoologíayAntropologíaFísica,FacultaddeBiología,UniversidaddeAlcalá,E- 28871 Alcalá de Henares, Madrid, Spain; E-mail: josedomingo.gilgado @uah.es&[email protected] H.López,DepartamentodeBiologíaAnimal,UniversidaddeLaLaguna,38206 LaLaguna,Tenerife,CanaryIslands,SpainandIslandEcologyandEvolution Research Group (IPNA-CSIC), 38206 La Laguna, Tenerife, Canary Islands, Spain;E-mail:[email protected] P.Oromí,DepartamentodeBiologíaAnimal,UniversidaddeLaLaguna,38206 LaLaguna,Tenerife,CanaryIslands,Spain;E-mail:[email protected] Received30June2010,accepted29October2010 1.Introduction accordingtosomeotherauthors(Bousquet2003) or even to the family Broscidae (sensu Jeannel The classification of the genus Broscus Panzer, 1941). Ball (1956) recognized three subtribes 1813 and related genera has been controversial within Broscini: Broscina, Barypina and fordecades.Thisgroupofgroundbeetlesisoften Creobiina, sections that were previously pro- given the status oftribe Broscini (Britton 1949, posed by Jeannel (1941) with the status of 1964, 1970, Ball 1960, Darlington 1965, Roig- subfamilies. Recently, Roig-Juñent (2000) pro- Juñent2000,Pawsonetal.2003,amongothers) posedtwosubtribesmore:AxonyinaandNotho- which is equivalent to the subfamily Broscinae broscina.Theincreasinglyrigorousstudieshave 46 Gilgadoetal. • ENTOMOL.FENNICAVol.22 broughtanewperspectiveofdiagnosticcharac- ginperfectlyreachingthebasalanglesofthepro- ters for these subtribes, and in the last analyses notum (Wollaston 1865, Machado 1992). It is some genera have been relocated again (Roig- easily foundpractically inthewholeareaoccu- Juñent2000).Mostofthetaxaareuniquetothe piedbythe“monteverde”forest(theproperlaurel SouthernHemisphereandasmallpartispresent forestplusthesocalledfayal-brezal)ofthecen- intheNorthernHemisphere,especiallyinthePa- tralmountainsofLaGomera,onlyavoidingthe laearcticregion.Thisdistribution,andacladistic drier wooded zones facing southwards. Wol- analysis based on 73 morphological characters laston (1865) did not mention this detail, but it led Roig-Juñent (2000) to propose the origin of mustbeconsideredthatLaGomerawastheonly Broscini on the Pacific coast of Pangaea, in the islandhenevervisited,havingdescribedthisand early Jurassic. Although different origins have manyotherGomeranbeetlespeciesaccordingto beensupposed(Jeannel1942,Britton1949,Ball the material provided by Crotch. Both Broscus 1956,Darlington1965,Erwin1985),thisseems andCarabusLinnaeus,1758aregenerawithfew tobethemostparsimonious.Furthermore,amo- speciesontheCanaries,andintheislandswhere lecularanalysis(Maddisonetal.1999)hasalso they occur together they usually share habitat, suggestedaratherearlydivergence. probably competing for similar food resources Inlightofthecurrentknowledge,contraryto giventheircomparablesizeandhabits.Themark- Bousquet(2003)andinaccordancewiththecrite- edly higher abundance of B. crassimargo in re- rion of Roig-Juñent (2000), the Broscini of the specttotheothertwospeciesofBroscuscouldbe Palaearctic region are assignable to two sub- duetotheabsenceofCarabusinLaGomera,a tribes: Broscina and Axonyina, the latter being genus present in Tenerife (Carabus abbreviatus themostdiverseanddisparate.WithinBroscina Brullé,1835andCarabusfaustusBrullé,1839) thegenusBroscusisthemostrepresentative(25 andinGranCanaria(CarabuscoarctatusBrullé, species)andwidelydistributed,beingpresentin 1839).BroscusrutilansfromTenerifeisfoundin Asia, Europe, North Africa, the Canary Islands themarginalzonesabovethelaurelforest(fayal- and introduced in North America (Bousquet brezal),inthehumidpineforestontheNorthof 2003). theisland, andsometimesinthetransitionzone ThegenusBroscusisrepresentedintheCana- between the pine forest and the high mountain rianarchipelagobythreecloselyrelatedspecies, scrub(Machado1992,owndata).Carabusabb- eachoneendemictoasingleisland:Broscusgla- reviatusisalsofoundinpracticallyalllocations ber(Brullé,1836)fromGranCanaria,B.rutilans whereB.rutilansoccurs,andusuallymoreabun- Wollaston, 1862 from Tenerife and B. crassi- dantlythanthelatter.InGranCanaria,B.glaber margo Wollaston, 1865 from La Gomera. Ac- is typically occurring in the mountain forest ar- cordingtoAntoine(1955)andMachado(1992) eas, mainly in more or less humid pine woods, they are probably related to B. politus (Dejean, thoughactuallyitisalsofoundinopendeforested 1828) from North Africa and Sicily, for having areas.AtthetimeofWollaston(1864)itwasalso theejaculatoryducthighlysclerotized,acharac- collectedinformerwoodlandsitesatloweralti- terabsentintheremainingspeciesofthegenus. tudelikeElMonte,whereitdoesnotliveatpres- However,theshapeoftheCanarianspeciesdiffer ent.ItusuallycoexistedwithCarabuscoarctatus, bytheirelytrabeinglessconvexandwithmore butbothspecieshavebecomeparticularlyscarce ovateoutline(subparallelinB.politus)seenfrom nowadays. In any case, B. crassimargo in La above, and they are micropterous contrarily to Gomeralaurelforesthaspopulationdensitiesal- B.politus,probablyduetotheiradaptationtoin- ways higher than the combined individuals of sularenvironments. CarabusandBroscusperareainanybiotopeof Broscus crassimargo is the largest (20–24 TenerifeorGranCanaria(ownobservations). mm),themoststrictlyforest-dwellingandbyfar Broscuscrassimargoisaspeciesusuallyoc- themostabundantofthethreeCanarianspecies, curringunderstonesandfallentrunks,andithad beingalsodifferentbyitsblackishfirstantenno- alsobeenrecordedbyMedina&Oromí(1990)in mere(darkredintheothertwospecies)andbyits the mesovoid shallow substratum (henceforth duller,moreflattenedelytrawiththelateralmar- MSS;seeJuberthie1983andCulver2001).Me- ENTOMOL.FENNICAVol.22 • FirstinstarlarvaofBroscuscrassimargo 47 dina(1991) considered that B. crassimargohad ofthemwereplacedfivemetersapart,separated beencollectedinthisparticularsubterraneanhab- two hundred meters from the other two in the itatjustoccasionally.However,ithasbeencap- same conditions. The traps were working from tured repeatedly along a recent study on the ar- January2008toJune2010,theircontentsbeing thropodfaunaintheMSSofLaGomeralaurelfo- revisedtwiceayear(January/FebruaryandJune/ rest(unpublishedowndata).Mostoftheindivid- July).Thesamplesofeachtrapwerefilteredon ualscollectedinthetrapsareadults,butalsoone place and kept in separate vials with propylene larvaofthisspecieshasbeenobtained.Thelarva glycol,veryappropriatetopreservetheDNAof ofB.crassimargo(aswellasthoseofanyCana- thecapturedindividualsforgeneticstudies(Ru- rianBroscus)waspreviouslyunknown.Accord- binketal.2003). ingly,larvaldescriptionanditscomparisonwith thearchetypicalmodelproposedbyBousquet& Goulet(1984)isthemainsubjectofthepresent 2.2.FirstinstarlarvaofBroscuscrassimargo article.Thismeansthat,afterthedescriptionofB. cephalotes(seeLuff1978,Sharova&Makarov Afirstinstarlarvawasobtainedon04/01/2010. 1984)andB.punctatus(seeSharova&Makarov This larva was dissected, extracting the labium, 1984),thisisthethirdBroscusspeciesonwhich mandibles, maxillae, antennae, cephaliccapsule datarelatedtothelarvaearegiven. sclerites,legs,andtergalandsternalscleritesby using dissection tweezers. These pieces were soakedinthewater-solubleresinDimethylHy- 2.Materialsandmethods dantoin Formaldehyde (DMHF) (Steedman 1958)andplacedonacetatesheetsforuseasmi- 2.1.Studyareaandsamplingmethod croscope slides, which measured 1.5 × 0.5 cm. Anothersmallacetatesheetwasplacedoneach ThesamplingwascarriedoutatReventónOscuro slideasacoverslipforobservationunderthemi- (UTM28R282330/3113130), alocationwithin croscope.Themicroscopeslideswiththelarvae GarajonayNationalPark(LaGomera,CanaryIs- dissected are deposited at Vicente M. Ortuño’s lands)whichincludesoneofthebestrepresenta- (VMO/AU) collection at the Department Zool- tionsofhumidlaurelforestinthearchipelago.A ogyandPhysicalAnthropologyoftheUniversity debrismesovoidshallowsubstratum(MSS)(see ofAlcalá. Juberthie 1983) on a steep slope was selected, ThehabituswasdrawnusingaNIKONSMZ- originated by colluviation at the base of rocky 1000 stereoscopic binocular microscope. Each cliffs,butprobablyalsoincreasedbystonydebris preparationwasobservedandmeasuredwithan slippingdownslopeduringtheconstructionofan optical microscope ZEISS 474620-9900, with old forest road. These colluvia are formed by cameralucidaandacalibratedocularmicrometer. mid-tosmallsizestonescoveredbyathinlayer Thehabitusandpreparationsweredrawninink. ofsoil,constitutingasubterraneanhabitatwitha The drawings were scanned and labelled using network of abundant interstices suitable for an theapplicationAdobePhotoshopCs8.0. abundantfauna.Thethicknessofthesecolluviais The adopted nomenclature for the setae and unknown, but according to our prospections pores is that proposed by Bousquet & Goulet whensettingthetrapstheymustreachatleast1m (1984). According to this criterion, setae are deep. The canopy cover of the area is close to namedwithnumbers,andporeswithletters.The 100%, evergreen trees Laurus azorica (Seub.) supernumerary setae are named with Roman Franco, Ilex canariensis Poir., Picconia excelsa numbers, and supernumerary pores with Greek (Aiton) DC. and Myrica faya Aiton being the letters,whentheyarepresent. dominantspecies,providingapermanentpenum- In some parts of the anatomy of the larva it bra to the surface and humidity to the under- wasimpossibletoidentifysomeparticularpores, groundlayer. since more than one of those were found in the Four collecting traps were set following the sameareawheretheyshouldbelocated,accord- modeldescribedbyLópez&Oromí(2010).Two ing to the archetype proposed by Bousquet & 48 Gilgadoetal. • ENTOMOL.FENNICAVol.22 Table1.No.ofBroscuscrassimargoadultsandone larvacollectedinthetraps. Samplingperiod No. 04/01/2008–01/07/2008 1 01/07/2008–01/02/2009 15 01/02/2009–30/06/2009 4 30/06/2009–04/01/2010 18+1larva 04/01/2010–08/06/2010 1 Goulet (1984). In such cases, the application of theterminologyforgroupsofstructureswascho- sen,asithadbeenoccasionallydonewithsome setae. Examples are the groups of pores gPRi, gPRj,gMEe,amongothers. 3.Results 3.1.CollectedBroscuscrassimargo andotherinvertebrates Inthisstudy39adultsandonelarvaofB.crassi- margowerecapturedintheMSStraps,butindif- ferentnumbersdependingonthesamplingperi- od,sothatthetotalspecimens(Table1)collected ineachperiodishigherinthesecondhalfofeach year. Besides B. crassimargo, we collected in thesetrapsawiderangeofinvertebratesthatoc- Fig.1.HabitusofthefirstinstarlarvaofB.crassi- margo.Scalebar2mm. cupytheundergroundhabitatofthisarea,varying from species with marked subterranean adapta- tionstonon-adaptedspeciesthatventureunder- and Aptilotus sp. (Diptera). Other epiedaphic groundoccasionallyoraccidentally.Thebeetles carabids like Calathus laureticola Wollaston, Pseudoplatyderus amblyops Bolívar, 1940, Do- 1865, Trechus flavocinctus gomerae Jeannel, mene jonayi Hernández & Medina, 1990 and 1936, Paraeutrichopus harpaloides (Wollaston, EuconnusspecususVit,2004,andthemillipede 1864) and Dicrodontus aptinoides (Wollaston, GlomeriscanariensisGolovatch,1987standout 1865) were collected occasionally. However, in the first group. Several edaphobionts with a epigean species of Calathus Bonelli, 1810 and lower degree of subterranean adaptation were CymindisLatreille,1806frequentlyfoundonthe also collected, particularly the beetle Aeletes surface around the traps were never caught in gemmula (Wollaston, 1865) and the millipede theseMSSsamples. Blaniulussp.besidesabundantoribatidmites.Fi- nally, the humicolous and epiedaphic species 3.2.Descriptionofthefirstinstarlarva weretherichestandmostdiversegroupcollected ofBroscuscrassimargo inthesetraps,withanotableabundanceofPlut- onia oromii (Ibáñez & Alonso, 1988) (Pulmo- Habitus (Fig. 1). Dark brown to reddish larva, nata), Brachydesmus sp. (Polydesmida), Eluma 18.7 mm long from the nasale to the apex of caelata (Miers, 1877) (Isopoda), Gomerina pygidium. Massive head (almost as wide as the calathiformis (Wollaston, 1865) (Coleoptera) pronotum), body gradually tapering backwards, ENTOMOL.FENNICAVol.22 • FirstinstarlarvaofBroscuscrassimargo 49 Fig.2.Firstinstarlarva ofB.crassimargo.Ce- phalicpieces.–a. Frontale.–b.Parietalin dorsalview.–c.Pari- etalinventralview. –d.Labiumindorsal view.–e.Rightmaxilla indorsalview.–f.Right maxillainventralview. –g.Rightmandiblein dorsalview.–h.Right antennaindorsalview. –i.Rightantennain ventralview.Scale bars,a–c:1mm;d–f: 0.5mm;g:1mm;h–i: 0.5mm. as in the third instar of Broscus cephalotes ac- (PA1–PA19),lackingsetaPR8,butwithonesu- cording to the description by Luff (1993); rela- pernumerary PRI. There are only eight distin- tivelyshortlegs. guishablepores(PAa-PRd,PRk,PRm-PRo).La- Cephaliccapsule.Epicranialsuturelessthana bium(Fig.2d)withthreepores(LAa–LAc)and thirdofthefrontalelength.Frontalealmosttrian- only four distinguishable setae (LA2–LA3, gular,1.61mmlongand1.98mmwide(Fig.2a). LA5–LA6); it is so pubescent dorsally that the It bears ten setae (FR1–FR10) and five distin- setaeLA1andLA4areindistinguishable.There guishable pores (FRa–FRd) at each side of the isaveryshortprotuberance,correspondingtothe sagittalplane,oneofthemsupernumerary(FR(cid:1)), ligula,withtwosetae(LA6)almostaslongasthe andlackingFRc.Therearetwoeggbursters.The last labial palpomere. Maxillae (Figs. 2e,f) ap- nasale is almost flat, but slightly curved and proximately1.86mminlength,pubescentinthe slightly acuminate at the extremes. Parietale inner dorsal face. Palp cylindrical, with four (Figs.2b,c)withsixstemmataaroundtheocular palpomeres.Galeawithtwogaleomeres,approx- protuberance. The parietale has a conspicuous imately as long as the two first palpomeres. lateral constriction, and bears eighteen setae Lacinia absent. The maxilla bears ten setae 50 Gilgadoetal. • ENTOMOL.FENNICAVol.22 Fig.3.Firstinstarlarva ofB.crassimargo.–a. Pronotum.–b.Pro- thoraxandmesothorax inventralview.–c.Me- sonotum.–d.Protho- racicrightleg.–e.Pro- thoracicrightleg.–f. Abdominaltergite-I. –g.Sterniteand pleuritesextendedof abdominalsegment-I. Scalebar:1mm. (MX1–MX11), MX6 indistinguishable because eleven setae (PR1–PR14), PR5, PR7 and PR13 ofthepubescence,andMX12absent;andeight absent;andeighteenpores(PRa–PRg):PReand pores (MXb–MXc, gMXe, MXf–MXg) with a PRhareabsent,butintherelativepositionofPRi, supernumerary pore in the third palpomere PRj, PRk and PRl there are groups of pores (MX(cid:1)),intherelativepositionofMXethereare (gPRi–gPRl)severalpores.Prosternum(Fig.3b) threepores(gMXe)andtheporeMXaisabsent. withgPS,PS1andPS2present.Episternum(ES) Mandible sharp, long (1.69 mm in length) and andepimeron(EM)fused,withasclerotizedre- curved(Fig.2g),withoneseta(MN1)andthree gionbetweenthem,eachonebearingagroupof pores(MNa–MNc).Itbearsashortbutsharpened setae(gESandgEM).Mesonotum(Fig.3c)1.40 retinaculum.Antennae(Figs.2h,i)1.66mmlong, mminlengthand3.22mminwidth,bearingfour- with four antennomeres, and a sensory append- teen setae (ME1–ME14) and thirteen pores ageonthethirdone;itbearssevensetae(AN1– (MEa–gMEl); there are several supernumerary AN7), with AN6 very reduced and only five pores, the ME(cid:1) and, similarly to the pronotum, pores (ANa–ANe), since ANf and ANg are ab- groupsofpores(gMEeandgMEf)intherelative sent. position of the pores MEe and MEf. Meso- Thorax.Inallthoracictergitesthereisavisi- sternumbearingsixsetae(MS1–MS6),trochan- blemedialsuture.Pronotum(Fig.3a)2.22mmin tin with a group of four setae (gTS1) and epi- lengthand3.37mminwidth,withalateralcon- meronwithanumerousgroupofsetae(gEM1). strictionapproximatelyinthefirstthird,bearing Pleuronwithalongseta(PL1). ENTOMOL.FENNICAVol.22 • FirstinstarlarvaofBroscuscrassimargo 51 Fig.4.Firstinstarlarva ofB.crassimargo.–a. Urogomphiindorsal view.–b.Pygidiumin dorsalview.–c.Pygi- diuminventralview. Scalebar:1mm. Legs(Figs.3d,e).Similarinsizeandchaeto- aconspicuousspiracle,whichisnotpresentinthe taxy,withoneclaw,lesspigmentedthantergites, restofabdominalsegments.Theurogomphi(Fig. andrelativelyshortmeasuring4.23mmapproxi- 4a) are 2.75 mm long, similar to the model of matelyfromthebasisofthecoxatothetipofthe Bousquet & Goulet (1984), bearing nine setae claw.Thedescriptionisbasedontheprothoracic (UR1–UR9)andsevenpores:(URa–URf),with leg.Coxawithsixteensetae(CO1–CO17),lack- URd and URg absent, and two supernumerary ingCO10.Threevisiblepores(COa–COc).Tro- (UR(cid:1)andUR(cid:3)).Pygidium(Figs.4b,c)1.36mm chanter with eight setae (TR1–TR8), and seven in length and 0.53 mm in width approximately, pores (COa–COg). Femur bearing seven setae bearing seven setae (PY1–PY7), lacking PY4 (FE1–FE7)andtwopores(FEaandFEc).Tibia andPY5,andincludingtwosupernumerary(PYI withsevensetae(TI1–TI7)andtwopores(TIa– and PYII). There are six pores: (PYa, PYb and TIb).Tarsuswithfivesetae(TA1–TA7),lacking PYf),threeofthemsupernumerary(PY(cid:1)–PY(cid:2)). TA3andTA6;setaeTA4andTA5veryreduced. Claw with two conspicuous setae (UN1 and UN2). 4.Discussion Abdomen.Lengthapproximately10.37mm, measuredfromthefirstabdominalsegmenttothe 4.1.FirstinstarlarvaofBroscuscrassimargo end of the pygidium. The abdominal tergite-I (Fig.3f)is0.94mminlengthand2.61inwidth.It The effectiveness of larval characters to build a bearselevensetae(TE1–TE11)andsevenclearly precisebeetlesystematicshasalreadybeendem- distinguishable pores, (TEa–TEd) and three su- onstrated (Beutel 1993, Solodovnikov 2007). pernumerary (TE(cid:1)–TE(cid:2)). The sternites of ab- Thisisthereasonwhereby moreandmorespe- dominalsegment-I(Fig.3g)withfoursetae(ST1, cificstudiesonlarvalcharactershavebeenincor- ST2,ST4andST6),andtwogroupsofsupernu- porated to the first treatises and compendia on merarysetae(gST3andgST5)intherelativepo- Coleoptera larvae. Preimaginal characters pro- sition of ST3 and ST5 respectively. There is a videagreatdealofanatomicalinformation,inad- poreST(cid:1).Theepipleuritebearstwosetae(EP1 dition to those already available on the imagos. and EP2). Hypopleurite with a well developed Clearly,thelarvaisveryrelevantforsystematics setaHPI,andagroupofsetaegHPII.Thereisalso asitisanothergenotypicexpressionofthespe- 52 Gilgadoetal. • ENTOMOL.FENNICAVol.22 cies(Goulet1979,Luff1993)andfromtheeco- lotesisathirdinstarlarva,andthatofB.crassi- logicalpointofview,theyoftenoccupydifferent margoafirstinstar,thedifferencesbetweenthem niches and can exploit different food resources. couldbeduetotheirdifferentstagesofdevelop- For this reason, the selective pressures do not mentandthereforewouldnotbeusefulforspe- needtobethesameinlarvalandadultstages,and cific discrimination, therefore those differences the preimaginal instars can show very different are not presented here. However, the study of evolutionaryrhythmsthantheimagoes.Asare- chaetotaxyinthefirststageofB.cephalotesusing sult,theycanshowalready“lost”featuresinthe thecriterionofBousquet&Goulet(1984),most imagoes,whichcouldhelptoinferthephylogen- likelywouldrevealmoresignificantdifferences eticrelationshipsofspecies. withrespecttoB.crassimargo. However,thestudyofpreimaginalmorphol- ThestudyofthelarvaofB.crassimargohas ogy posesaseriesofdifficulties(Solodovnikov revealed an extraordinary resemblance (number 2007) which are, of course, also present in the and topology of pores and sensory setae) to the study ofthelarvaofB.crassimargo:a)thelow model of Bousquet & Goulet (1984), although numberofspecimensincollections,b)theneedto theydidnotuseanyspeciesofBroscinithatcon- dissect and make preparations for microscopic tributed with its characters to the archetypical observationofsomestructures,c)theexistenceof proposal.Thisrelatestotheprimitivenessofthis intraspecific variability in some characters such group of Carabidae. Very probably the diver- aschaetotaxy(incaseofasinglespecimenmay genceoftheBroscinifromotherCarabidaehada bediscerniblebyasymmetryonbothsidesofthe verybasalorigin,andsotheycouldhaveretained sagittalplane),andd)thedifficultyofdetermin- muchoftheearlylarvalcharacters.Thisevidence ingwhetheracharacterishomologousornotin coming from the study of larval chaetotaxy is severaltaxa. supportedbyotherstudiesonimaginalmorphol- Thefindingandstudyofthepresentlarvaof ogy (Roig-Juñent2000),andmolecularbiology B. crassimargo is a return to the incipient re- (Maddisonetal.1999). search line on the preimaginal stages of the en- It is possible that the species of this lineage demic Canarian Carabidae (see Raynaud 1970, havemaintainedalifestyleverysimilartoprimi- Arndt1991).AccordingtoMachado(1992),this tivespecies,notbeingnecessarytoadapttooradi- line of research has only two earlier contribu- callytodifferentlivingconditions,thusprevent- tions: one concerning Carabus abbreviatus ing remarkable structural changes (apomor- (Carabinae)andtheothertoZarguscrotchianus phies).Inrelationtothis,Erwin(1985)postulates Wollaston,1865(Licininae). thatthefirstgroundbeetleswerenaturalofhigh Furthermore,thedescriptionofthislarvabe- humidity,orwater-relatedenvironments,assug- comesimportantfromamethodologicalpointof gestedbyitsrelationshiptootherAdephagalike view,sincethoughotherBroscinilarvaehaveal- Dytiscidae, and their almost anecdotal presence ready been described (Gardner 1931, Jeannel inthemostxericareasoftheplanet.Thus,thisen- 1941,Moore1964,Andersen1968,Harris1978, vironment would have been the evolutionary 1980, Luff 1978, 1993, Townsend 1971, 1988, centre of dispersal, and therefore in the most Sharova&Makarov1984,Arndt1991,Davidson primitivegroupstendtobeorganicallylinkedto &Ball1998),thisisthefirstspeciesofthistribe humidenvironments(coasts,riparianandmarsh inwhichthenomenclatorialcriterionofBousquet areas,woodedareas,etc.). & Goulet (1984) is applied, as done by Arndt (1991)forthedescriptionofZarguscrotchianus. Thiswillallowamoreprecisecomparisonwith 4.2.TheoccurrenceofBroscuscrassimargo other Carabidae larvae and also with the arche- intheMSS typeproposedbyBousquet&Goulet(1984). So far, the most and best studied Broscini The presence of certain epigean species in the larvaisthatofB.cephalotes(Jeannel1941,Luff Canarian MSS is a constant feature in the few 1978, 1993, Sharova & Makarov 1984). How- studiescarriedoutsofarinthisenvironment(Me- ever,giventhatthedescribedlarvaofB.cepha- dina1991,Medina&Oromí1990,Oromíetal. ENTOMOL.FENNICAVol.22 • FirstinstarlarvaofBroscuscrassimargo 53 1986,owndata),includingsomemediumtolarge (winter/spring), a more humid period when po- size beetles (Carabidae and Staphylinidae) like tential prey are abundant in epigean environ- Broscus, Carabus, Ocypus Leach, 1819 and ments.Asimilarpatternofcaptureshasbeenob- ProtogoeriusCoiffait,1956.Butsuchspeciesoc- servedinthepredatorybeetlesEuconnusspecu- curparticularlyintheMSSswithmoreinterstitial susandOcypussilvaticusWollaston,1865.Prob- profusion,usuallycoincidingwiththoseofcollu- ably the latter is more abundant in the sum- vial origin (debris MSS). Contrarily, the MSS mer/autumn for the same reasons as B. crassi- formed by volcanic clinker is usually more iso- margo,buttheabundanceofE.specususisprob- lated from the surface and their interstices are ablyrelatedtoitsnaturalphenology,sinceitisa moresealed,consequentlybeinglesspracticable troglobiont beetle which permanently occupies forbigepigeanspeciesusuallylargerthanthose an underground layer hardly influenced by sea- adaptedtoliveunderground. sonalchanges. As we have observed along years of studies ItisstatedthatB.crassimargooccursrather on this subterranean fauna (unpublished data) frequentlyintheMSSherestudied,butitisnot BroscusandCarabushavesometendencytoen- clearwhethertheyjustoccupyshallowlayersor ter in such colluvia. However, no Broscus have reach deeper levels of the colluvium. The trap ever been collected in the MSS of Tenerife or modelwehaveusedworksidenticallyforarank GranCanaria,whilethelocalspeciesofCarabus between15and80cm.Tosolvethisquestionit were sometimes present (occasionally even wouldbenecessarytouseaselectivetrapfordif- abundantincertaintrapsinTenerife).Thepres- ferent depths (see Schlick-Steiner & Steiner enceofB.crassimargointheMSSofLaGomera 2000,Laškaetal.2008,inpress). couldsuggestthat,giventheabsenceofCarabus LarvaeofCarabusorBroscushadneverbeen inthisisland,theformerhasoccupiedanichenot capturedbeforeintheMSSoftheCanaryIslands, availableintheothertwoislandsduetothecom- forwhichprobablytheirpresenceinthisenviron- petition of Carabus. The absence of large sized mentcouldbeoccasional,contrarilytotheadults, troglobiticgroundbeetlesprobably favoursthat which are relatively common as commented BroscusandCarabusinvadetemporarilytheun- above.Accordingtotheecologicalclassification dergroundtoexploitanemptyniche.Instead,in proposed by Sharova (2008), the larvae of the present case study in La Gomera there is a Broscusaregeobiontsbelongingtothe“burrow- poorrepresentationofmidtosmallsizeepigean ing forms”, and this soil burrowing lifestyle is ground beetles with the exception of Gomerina also confirmed by the morphology of their tho- calathiformis,aspecieswithcleartendencytoin- racicendoskeleton(Zaitsev2008),somaybeset- vade shallow underground layers and already tingtrapsinthepropersoilaroundthesiteswhere capturedbyMedina(1991)intheMSSofthisis- B. crassimargo has been obtained in the MSS, land.Thisscarcitymustbeduetotheabundance could be useful to check their endogean or ofthetroglobiticPseudoplatyderusamblyopsin hypogeanpreferences.Thelatterislessprobable the samples, a blind 9 mm long ground beetle since debris MSS sites are not easy to find and whichisbyfarthemostabundant(asmuchas247 probably represent a minimum part of the total individualscollected)amonganysizecategory. distributionalareaofthespeciesinLaGomera. Probably both Broscus and Carabus invade theMSSfollowingpreyssuchasslugsthatneed Acknowledgements.WewanttothankVerónicaGonzález high humidity, always present in the MSS but Araujoforrevisingthegrammarandforhersuggestions withtheEnglish.Thisstudyhasbeenpartiallyfinancedby onlyseasonallyonthesurface.Thiscouldexplain theI3programof“IncentivationoftheIncorporationand whythenumberofBroscuscollectedintheMSS IntensificationonResearchActivityoftheMinistryofEd- at Reventón Oscuro laurel forest was much ucationandScienceofSpain,ofwhichVicenteOrtuñois higherinthesummer/fallthaninthemorehumid thebeneficiary,andbythe025/2007researchprojectofthe winter.Onthecontrary,afterananalysisofsur- alsoSpanishMinistryofNatural,RuralandMarineEnvi- ronmentcarriedoutbyP.Oromí,H.Lópezandcollabora- facerecordsofB.crassimargointhelaurelforest torsinGarajonayNationalPark. of Gomera, Machado (1992) pointed out that it was more abundant in the first half of the year 54 Gilgadoetal. • ENTOMOL.FENNICAVol.22 References Goulet,H.1979:Contributionsofcharactersoflarvaeto systematicsofCarabidae.—In:Erwin,T.L.,Ball,G. Andersen,J.1968:ThelarvaofMiscoderaarcticaPayk. E.,WhiteheadD.R.&HarpenA.L.(eds.),Carabid (Col.,Carabidae).—NorskEntomologiskTidsskrift beetles:theirevolution,naturalhistoryandclassifica- 15:71–74. tion:205–208.Dr.JunkbvPubl.,TheHage. Antoine,M.1955:ColéoptèresCarabiquesduMaroc(1ère Harris,A.C.1978:TheLarvaofBrulleaantarctica(Cole- partie).—MémoiresdelaSociétédeSciencesNatu- optera:Carabidae:Broscinae).—TheNewZealand rellesetPhysiquesduMaroc,Zoologie(Nouv.Série) Entomologist6:401–405. 1:1–177.[InFrench.] Harris,A.C.1980:TheLarvaofBrulleaantarctica(Cole- Arndt,E.1991:BeitragzurKenntnisderLicinini-Larven optera:Carabidae:Broscinae):Note.—TheNewZe- (Coleoptera, Carabidae). — Entomologische Nach- alandEntomologist7:174–175. richtenundBerichte35:117–122.[InGerman.] Jeannel,R.1941:FaunedeFrance,39.ColéoptèresCara- Ball,G.E.1956:NotesonthegenusZacotusLaConte, biques.Premièrepartie.—Lechevalier,Paris.571pp. 1869, and the classification of the tribe Broscini (= [InFrench.] Broscidae sensu Jeannel, 1941. Coleoptera, Carabi- Jeannel,R.1942:Lagenèsedesfaunesterrestres:éléments dae).—TheColeopteristsBulletin10(3):33–52. debiogéographie.—PressesUniversitairesdeFran- Ball,G.E.1960:Carabidae(Latreille,1810);theground ce.513pp.[InFrench.] beetles.Fascicle4.—In:Arnett,R.H.(Editorand Juberthie,C.1983:Lemilieusouterrain:étendueetcarac- principalauthor),ThebeetlesoftheUnitedStates:55– téristiques.—MémoiresdeBiospéologie10:17–65. 182. The Catholic University of America Press, [InFrench.] Washington,D.C.xi+1112pp. Laška,V.,Mikula,J.,R(cid:1)(cid:1)i(cid:2)ka,V.,Véle,A.,Šarapatka,B. Beutel, R. G. 1993: Phylogenetic analysis of Adephaga &Tuf,I.:Depthdistributionofspidersinsoilprofile. (Coleoptera)basedoncharactersofthelarvalhead.— —JournalofArachnology.(Inpress.) SystematicEntomology18:127–147. Laška,V.,Mikula,J.&Tuf,I.H.2008:Jakhluboko(cid:1)ijí Bousquet,Y.2003:Carabidae:Broscinae.—In:Löbl,I.& p(cid:1)dníbezobratlí?[Howdeepdosoilinvertebratesli- Smetana,A.(eds.),CatalogueofPalaearcticColeop- ve?]—(cid:2)iva56:169–171.[InCzech.] tera.Vol.1:235–237.ApolloBooks,Stenstrup.819 López,H.D.&Oromí,P.2010:Apitfalltrapforsampling pp. the mesovoid shallow substratum (MSS) fauna. — Bousquet,Y.&Goulet,H.1984:Notationofprimarysetae SpeleobiologyNotes2:7–11. andporesonlarvaeofCarabidae(Coleoptera:Ade- Luff,M.L.1978:ThelarvaeoftheBritishCarabidae(Co- phaga).—CanadianJournalofZoology62:573–588. leoptera) V. Omophronini, Loricenini, Scaritini and Britton,E.B.1949:TheCarabidae(Coleoptera)ofNew Broscini.—Entomologist’sGazette29:265–287. Zealand.Part3.ArevisionoftheTribeBroscini.— Luff, M. L. 1993: The Carabidae (coleoptera) larvae of TransactionsoftheRoyalSocietyofNewZealand77: FennoscandiaandDenmark.—FaunaEntomologica 533–581. Scandinavica27:1–187. Britton, E. B. 1964: New Carabidae (Coleoptera) from Machado, A. 1992: Monografía de los carábidos de las ThreeKingsIslands,NewZealand.—NewZealand IslasCanarias.—InstitutodeEstudiosCanarios.La JournalofScience7:521–527. Laguna,734pp.[InSpanish.] Britton,E.B.1970:Coleoptera(Beetles).—In:Water- house,D.F.(ed.),TheinsectsofAustralia:495–621. Maddison,D.R.,Baker,M.D.&Ober,K.A.1999:Phylo- MelbourneUniversityPress.Canberra.1029pp. genyofcarabidbeetlesasinferredfrom18Sribosomal Culver,D.C.2001:Subterraneanecosystems.—Encyclo- DNA(Coleoptera: Carabidae). — Systematic Ento- pediaofBiodiversity5:527–540. mology24:103–138. Davidson,R.L.&Ball,G.E.1998:ThetribeBrosciniin Medina,A.L.1991:Elmediosubterráneosuperficialen Mexico:Rawlinsius papillatus, new genus and new lasIslasCanarias:caracterizaciónyconsideraciones species(Insecta:Coleoptera:Carabidae)withnoteson sobresufauna.—Ph.D.thesis,UniversidaddeLaLa- naturalhistoryandevolution.—AnnalsofCarnegie guna.Tenerife.[InSpanish.] Museum67:349–378. Medina,A.L.&Oromí,P.1990:Firstdataonthesuperfi- Darlington,P.J.J.1965:Biogeographyofthesouthernend cialundergroundcompartmentonLaGomera(Canary oftheWorld.DistributionandHistoryoffarsouthern Islands).—MémoiresdeBiospéologie17:87–91. lifeandland,withanassessmentofcontinentaldrift. Moore,B.P.1964:AustralianlarvalCarabidaeoftheSub- —CambridgeMA:HarvardUniversityPress.236pp. familiesBroscinae,PsydrinaeandPseudomorphinae Gardner,J.C.M.1931:ImmaturestagesofIndianColeop- (Coleoptera).—PacificInsects6:242–246. tera(8),(9).—IndianForestRecords(Entomology Oromí,P.,Medina,A.L.&TejedorM.L.1986:Ontheex- Series)16:49–89;91–111. istenceofasuperficialundergroundcompartmentin Erwin,T.L.1985:TheTaxonpulse:ageneralpatternofli- theCanaryIslands.—ActasdelIXCongresoInterna- neageradiationandextinctionamongcarabidbeetles. cionaldeEspeleología,Barcelona2:147–151. — In: Taxonomy, Phylogeny and Zoogeography of Pawson,S.M.,Emberson,R.M.,Armstrong,K.F.&Pa- beetles and ants: 437–472. Dr W. Junk Publishers. terson,A.M.2003:Phylogeneticrevisionoftheende- Dordrecht.xiii+514pp. micNewZealandcarabidgenusOregusPutzeys(Co-