A Revision of the Japanese Species of the Genera Elodes and Sacodes (Coleoptera, Scirtidae)

69 Pages·1997·75.1 MB·English

by  Yoshitomi, H

E:h,l,・a,'fok、o,25(2):349-417,Novemberl5,1997
ARevisionoftheJapaneseSpeciesoftheGenera
E1odesandSacodes(Coleoptera,Scirtidae)
HiroyukiYosHIToMI
ZoologicalLaboratory,MeijoUniversity,
Tempaku-ku,Nagoya,468Japan*
Abstract The Japanese speciesof the genera E/odes LATREILLE, 1796 and
SacodesLECoNTE, l853arerevised.SacodesisaseniorsynonymofFlavo1/e1odesKLAus-
NITzER,1980.Fivespeciesof thegenusE1otiesandsixofthegenusSacot/esarerecog-
nized. 0fthese,E/odeselegansandSacode.・l tsils/11,nenslsarenew toscience.TheJapa-
nesespeciesofE/odesaredividedintotwospecies-groups:themat-gl,lataspecies-group
comprisingE. ino1・nata L三1wis, E.、l・11so111PIcandE.sapu/a1・IsLEWIS,andthe,11imlta
species-groupcomprisingE elega11ssp nov and E koJ1111a1NAKANE.E1odesohba、,ash11
M. SATo and Flavo/1e1odes t11grata KLAUsNITzER are junior synonymsof E kojimal
NAKANE.Sal'aband1ls111ontlcolaNAKANEisajuniorsynonymofE. _1son1Plc.Fournew
combinationsareproposedinthegenusSa(・odes.vl,.,naka11el,a,11amiens1s.,,nln1,naand
加_、.
Descriptionsofthetwogeneraaregivenwithkeystospecies.Alltheadultsheredealt
,. withandtheimmaturestagesof 加etna'a,9.ll,fisc川,1.人,o/加al,S.IlaXane1 S pl-o'ecf
.
andSdu.、-aredescribedorredescribedwithfigures.
Introduction
E1odesLATREILLE,1796isthethirdlargestgenusofthe familyScirtidaeandis
representedbyabout100speciesfromallovertheworld.Flavohe1odesKLAUsNITzER,
1980waserectedforthefavlco11isspecies-groupofthegenusE1odesandcontains17
speciesrecorded fromtheHolarcticandtheOrientalRegions.Thesegeneraarecon-
sideredcloselyrelatedtoeachotherandshowsister-grouprelationshipwithotherscir-
tidgeneraon thebasis of phylogenicstudies of adults and larvae (KLAusNITzER,
1974a; HANNAPPEL &PAULUS,1987). Unfortunately, Flavohe1odes isajuniorsyn-
onymofSacodesLECoNTE,1853describedonthreeNorthAmericanspecies.
ThefirststudyontheJapanesespeciesofthegenusE1odesanditsrelativeswas
madebyKIEsENwETTER(1874)whorecordedHe1odesflavlco11isKIESENwETTERfrom
Nagasaki.Sincethen,manytaxonomicandfaunalstudieswerepublishedbythe fol-
lowingentomologists: HAROLD (1881); LEWIS (1895); PIC (1914, 1918); NAKANE
*Presentaddress:BioindicatorCo., Ltd.,Takada3-l6-4,Toshima-ku,Tokyo,171Japan
350 HiroyukiYosHIToMI
(1963); SAT0 (1966, 1985a, b, l989), SAT0 & CHUJ0 (1972); SAToU (1975) and
KLAUsNITzER(1973,1974b,1980a,1995). Twelvespecieshavehithertobeenrecog-
nized fromJapanunder the following threegenera:E1odes, Flavohe1odesandSa1-a-
bandusLEECH,1955,butnocomprehensivestudyaboutthesehasyetbeenmade.Be-
sides, therehasbeennostudyabout theimmaturestageandbiology, except HAYAsHl
(l957).
Inthispaper,IamgoingtorevisethegeneraE1odesandSacodesofJapan,with
biological notesanddescriptions of theimmaturestages ofsixspecies,viz., three
E1odesandthreeSacodes.
MaterialsandMethods
Thisstudy ismainlybasedondried(adults)andalcoholic(larvae, pupaeand
adults;preserved in70%ethanol)specimensinmycollection. Inaddition, I wasable
toborrow andexaminemanyspecimenspreserved in the following institutionsand
personal collections: EUM-Entomo1ogica1 Laboratory, Ehime University, Matsu-
yama;KMNH- KurashikiMuseumofNaturalHistory;NWU-Bio1ogica1Laboratory,
Nagoya Women's University; TMNH-Toyohashi Museum of Natural History;
TPM -Tochigi Prefectural Museum; TN-T. NAKANEs' private collection; SO-S.
OHMOM0s' privatecOllection;SI-S. IMASAKAs' privatecOllection;SS-S. SAKURAI's
privatecollection;YH-Y.HIRANos' privatecollection.
Theho1otypesandsomeparatypesofthetwospeciestobedescribedhereinwill
bepreservedintheNationalScienceMuseum(Nat.Hist),Tokyo,andotherparatypes
areintheBiologicalLaboratory,NagoyaWomen'sUniversityandinmypersonal col-
lection.
Generalobservationanddissectionweremadeunderastereoscopicmicroscope.
Microstructureswereobservedunderamicroscopeondissectedpartmountedonhol-
lowslideswithpureglycerine(mainlyusedfortegmenandpenis)orCanadaBalsam
(used forotherparts).Somemicrostructuresofadultsandlarvaewereobservedwith
SEM (HitachiS-2050).
TheterminologyrefersgenerallytoNYHoLM(1972,1984) for thegenitalorgan,
andmainlytoHANNAPPELandPAULUS(1991) for themouthpartsofthelarva. The
termsofsomestructuresoflarvalmouthpartsareshowninFig.1.
Theabbreviations formeasurementsused inthepresent paper areas follows:
HW- widthofhead;PL-lengthofpronotum;PW-widthofpronotum;EL-lengthof
elytra; EW-widthofelytra;TL-total length (PL plusEL inadult); TW-maximal
width(betweenleftandrighthindlegsinpupa).Totallengthismeasuredfromanterior
marginofclypeustoapex ofabdominalsegment in fullyextended larva,and from
apexofpronota1spinetoapexofabdominalsegmentinpupa.Arithmeticmeanofthe
measurement isgiveninparenthesesaftertherange. Ifpossible,twentyspecimensare
pickedup formeasurement inbothsexes.
E1odesandSacodesofJapan 351
Tb
A
Fig. 1. LarvaofE1odesino・,nata,showingtermsoflarvalmouthparts. - A,Labruminventralaspect
(epipharynx);B,hypopharynx.C:Cushion;Ca:clawapparatus;Cd:chitindent;Cp:combplate;Ct:
clawteeth;Et:epipharyngea1teeth; Ks:keel-sclerite;Tb:tooth-bristles;VI:ventrallobe;Vs:ventral
seta.
GenusElodesLATREILLE
[Japanesename:MaruhananomiZoku]
E1odes LATREILLE, 1796, Prec. Caract. Gen., 44. - PIc, 1914, Coleopt.Cat., (58): 21 [world list].
- PoPE,1976,Entom mon.Mag.,111:186.Typespecies:La''lpyt'is川' nutaLINNAEUS, l767(sub-
sequentdesignationbyLATREILLE,1810).
He1oales[incorrectspelling]:AGASSIZ,1847,Nom.Zoo1. lndexUniv.,393. - KLAusNITzER,1974,Zool.
Jb.Syst.,101:479. - SAT0,1985,Coleopt.JapanCol.,Osaka,2:420[key].
Sa,abandus:SAT0,1985,Coleopt.JapanCol.,Osaka、2:420[key]. ecLEECH,l955].
Adult. Bodymoderateinsizeforscirtidbeetles,TL2.8-6.0mm,ovaloroblong,
lightly or moderately convex above,shining,closelycoveredwithhairysetae. Col-
orationyellowtoblack,variablewithspecies.Headrathersmall,slightlyconvex,com-
pletelycoveredbypronotumandinvisibleindorsalview.Antennaefiliform,covered
withshortsetae,moreor lesslonger inmale;scapeovate,broadest;pedicel ovate,
small;3rdthesmallest,withdistalmargindiagonal;4ththelongest inmostspecies;
l ithoblong. Pronotumsemicircular, covered with setaewhichareeasily removed.
Scutellumtriangular,moderateinsize,visibleindorsal view.Elytraovalor oblong,
with rather longsetaewhichareeasily removed. Abdominal sternitescoveredwith
shortsetae.
Malegenital organ. Eighth tergitewellsclerotized, with apair of rather long
apodemes;8thsternitewellsclerotized;9thtergitemoderatelysclerotized,withapair
ofapodemes;9thsterniteweaklysclerotized,coveredwith longsetae. Tegmenwell
sclerotizecLrathersmaller ofthesamesizeaspenis,withdistinctparameres.Penis
wellsclerotized,stick-like,bifidinapicalpart(parameroids).
Femalegenitalorgan. Eighthtergitewithapairof rather longapodemes; 8th
352 HiroyukiYoslln'oMI
s1erniteovaltooblong.Ovipositorwithratherlongbaculus.
Lan,a. Bodywellsclerotize(i,campodeiform.Headvisibleindorsalview.An-
tennaefjliform,rathershort,reachingthorax;scapecurvedposteriorly,flagellumabout
30_50segmented. Labrumtransverse,withalmoststraightanteriormargin;epiphar-
ynxwithlongandsimplesetaeinanteriormarginofventrallobe,withapairofventral
setaewhosesocketshavesimplesurroundingparts. Mandiblespointedat terminal
tooth,with featheredbristlesininnerareas.Maxillarypalpiwithsomeshortsetaein
ventro-1atera1areaof1stsegment.Hypopharynxwithseparatedkeel-scleriteandsock-
etsoftooth-bristles,tri-ormulticornuteatapicalmarginsoftooth-bristles,withapair
of longsetaeonkeel-sclerite.Thoracesdistinctlybroader thanabdomen.Ninthab-
dominaltergitebicornuteatposteriormargin.
Pupa. Bodyverysoft,withtwopairsoflongspinesondorsalsurfaceofprono-
tum,withsimpleabdominalsegments.
Rema,・ks. Cistelapa11idaFABRIcIUs,1775wasdesignatedby LATREILLE(1810)
asthetypespeciesof thegenusE1odesLATREILLE,1796. However, thisspecieshas
been regardedasajuniorsynonymofE1odeslmntlta (LINNAEUS, 1767) which isa
commonandwellknownspeciesinEurope.
Thegenus is divided into two species-groups, namely ,na,-g1,lata and mlnuta
species-groups(KLAUsNITzER,1970;NYHOLM,1972).
Biologicalnotes. Thehabitatsof thelarvaeso far reportedaresmall streams
andclearponds(e.g.,LESAGE,1991;KLAUSNITZER,1996).
KeytotheJapaneseSpeciesoftheGenusElodes
1. Antennaandlegsmoderateinlength;bodyoval;(,na1glnataspecies-group) _ _2.
- Antennaeandlegslong;bodyoblong,almostparallel-sided;(,11inutaspecies-group)
4
2.Pronotumwithshallowanddistinctconcavities,seeminglydistinctlypunctate
E. ino1'nata LEWIS
- Pronotumfinelypunctate
3. Fronsandclypeusyellowinmale;7thsterniteshallowlyconcave...E.wiison1PIc
- Fronsandclypeusbrownishblack;7thsternitedeeplyconcave
E.scapularisLEWIS*)
4. Pronotumwithblackmarking;8thtergiteofmaletrapezoidal
! .A' 濶ﾁa NAKAN
*) Femalehasnotbeendeterminedyet
Fig. 2. HabitusofE1odesspp. - A, E. inc,・11ataLEWIS,male; B, E.、l,fisc,11Pfc, female(holotypeof
Sa'abandusmonticolaNAKANE,1963);C, typelabelsofSa''abandus'i1onticola;D, E scapula,・is
LEWIS,male;E,Ee/eganssp nov.,holotype,male;Fditto,paratype, female;G,E koJima1'NAKANE,
holotype,female;H,ditto,labels;I,ditto, female(1、olotypeofE.o/lba、,as/111M.SAT0,1985).
E1odesandSacodesofJapan 353
354 HiroyukiYosHIToM
:,11・ .-,.-,・・
-
: ,
I 益
-
-ま f
9
'、
.・
1
Fig.3. TypespecimensofE1odesspp.preservedintheBritishMuseum,London. - A, E. inc・,nata
LEWIS;B,E.scapula''IsLEWIS.PhotobyM.SAT0.
- Pronotumyellowishorange;8thtergiteofmaleformedbyrod-likehemitergites
Eeleganssp nov.
GroupofElodesmarginata
Thisspecies-groupischaracterizedbythefollowingfeatures:bodyoval;antennae
and legsrathershort; parameresdistinctlyserrate; apicesofpenis ratherround;ab-
dominaltergitesmorestronglysclerotizedthanthoseoftheminutaspecies-group.
ElodesinornataLEWIS,comb rev.
[Japanesename:Ko-kuro-maruhananomi]
(Figs 2A,3A,4A,5A,6-12,20A)
He1odesinornatusLEWSI,1895,Ann.Magnat.Hist.,(6),16:107(Type:inBritishMuseum,London,not
examine Fig3A).
E1odesinornata:PIc,1914,Coleopt.Cat.,(58):23.
Sa'a'ha'tdusinc''natus:NAKANE,1963,Icon.Ins.Japon.Col nat ed.,2:140,pl 70,fig. 18. _ SAT0,
1985,Coleopt.JapanCol.,Osaka,2:424,pl 77,fig31.
Adult. Body oval,moderately convex, closely covered with yellowish white
E1odesandSacodesofJapan 355
A
M
B
C -M (=l(::)
D
E
_
Fig 4. AntennaeofE1odesspp.(above,male;below,female). - A,E. inc・,nataLEWIS;B,E.、、,ilso,ll
Pfc;C,1.scapll/a,-isLEWIS;D, .e/ega1lsspnov;E, .A'oJ1'italNAKANE.(Scale:0.5mm)
hairs.Headblack; labrumyellowishbrown;maxillaryandlabialpalpiandmandibles
yellow,buttheapicesofmaxillaryandlabialpalpiaresomewhatdarker;1stto3rdan-
tennalsegmentsyellow;4thantennalsegmentbrownishyellow, itsapicalendsome-
whatdarker;5thto11thantennalsegmentsbrownishblack,but5thand6thsegments
paler; pronotumblack, butanterior and lateral margins paler;scutellumandelytra
brownishblack;ventralsurfaceofbodyblack; forelegsyellow,except forduskytarsi;
midcoxaeyellowtobrown,variableincolor;midfemorayellow,except forblackish
brownapexandposteriormargin;midtibiaeandtarsiblack;hindlegsblack,buthind
tarsipaler.
Headfinelyandsparselypunctate.Eyesmoderateinsize,prominent;thedistance
betweeneyesabout1.6timesaslongasthediameterofaneyeinmale,1.8timesinfe-
male.Frontmarginofclypeusstraight.Antennaemoderateinlength,reachingabout
proximal1/5ofelytra,broadestatapicalendof4thsegment;approximateratioofan-
tennal segments as 2.5:1.6:1.0:3.6:2.8:2.8:2.7:2.7:2.5:2.1:3.1 inmale (n=2,
mean)and2.6:1.7:1.0:3.5:3.l:2.9:2.9:2.7:2.6:2.3:3.4in female(n=2,mean).
pronotumsemicircular,sparsely andfinely punctate,closely coveredwithlargeand
shallowconcavitieswhichhaveasetaateachcenter;thedistancebetweenconcavities
of thesame lengthas adiameter ofconcavity; PW/PL 15-2.0 (1.7) in male and
1.6-1.9(1.7)in female.Scutellumfinelypunctate.Elytraoval,broadestatthemiddle,
withadeepanddistinctpuncturesituatedonposteriorendofeachsetalsocket,butthe
punctureisshallowandindistinctinproximalarea;EL/EW14-1.5(1.4)inmaleand
356 HiroyukiYosHIToMI
c
Fig.5. Sixthto7thabdominalsternitesofE1odesspp.(above,male;below,female). - A,E.inornata
LEWIS; B, 1. wl'fso川 PIc;C, 1.scapll/a''IsLEWIS;D, 1.e/eganssp nov;E, 1.A,of加fatNAKANE.
(Scales:0.5mm)
1.3-1.5 (1.4) in female;EL/PL2.8-3.7 (3.1) inmaleand2.9-3.7 (3.2) in female;
EW/PW l2-1.4(1.3) inmaleand13-1.4(1.3) in female; TL/EW l8-1.9(1.9) in
male and 18-2.0(1.8) in female.Ventral surfaceofbodycloselycoveredwithfine
punctures.Legsmoderateinlength.
Male. Apicalmarginof7thabdominalsterniteconcave.Eighthtergitesemicir-
cular,coveredwithminutespinesinapicalarea;8thsternitegingko-leafshaped,cov-
ered with minute spines on apical margin; 9th tergite moderately sclerotize(i, but
broadlymembranous inapicalandlateralareas,withapair ofstoutapodemes;9th
sterniteoblong,withlongsetaeatapicalmargin. Tegmenbifid inaboutapical 1/3
(parameres),withroundedapices; lateralmarginsofparameresserrateinapical1/5
and3/5tobase.Penisabout1.0mminlength,sparselycoveredwithpuncturesinapi-
cal 2/5,bifidinaboutapical1/5(parameroids),withroundedapices,withapairof
smallhooksataboutapical2/3oflateralmarginsofparameroids;dorso-proxima1mar-
gindeeplyconcave;ventro-proxima1margindeeplynotched.
Female. Apicalmarginof7thabdominalstemitearcuate.Eighthtergitemod-
eratelysclerotized,coveredwithfinepuncturesandminutespinesatapicalmargin;8th
sterniteweaklysclerotized,coveredwithfinepunctures,withdeeplynotchedapical
marginwhichiscoveredwithminutespines. 0vipositor moderatein length;stylus
E/odesandSacodesofJapan 357
with twosetaeatapicalend;coxiteandbaculuslong, finelypunctate;approximate
ratioofthelengthsofstylus,coxiteandbaculusas follows(n=2,mean): - 1.0:4.1:
139.
.
Measurements of adult. Male (n=20). TL: 2.8-3.8 (3.3)mm; EW: 1.5-2.0
Fig 6. E1odes lnornata LEWIS; A,head; B,metasternum;C,pronotum; D,ditto; E,caudalareaof
elytron;F,ditto,seta.
358 HiroyukiYosHIToM
F
Fig. 7(onp 358). .aodesinornataLEWSI. - A-F:Malegenitalia;A,8thtergite;B,8thsternite;C,
9thtergite;D,9thsternite;E, tegmen;F,penis,dorsalaspect. - G-I:Femalegenitalia;G,8thter-
gite;H,8thsternite;1,ovipositor.(Scales:0.5mm)
(l.8)mm;PL:0.6-1.0(0.8)mm;EL:2.2-2.8(2.5)mm;PW:1.2-1.5(1.3)mm.Female
(n=20). TL: 3.1-4.2 (3.7)mm; EW: 1.7-2.3 (2.0)mm;PL: 0.7-1.0 (0.9)mm; EL:
2.4-3.3(2.8)mm;PW:1.3-1.6(1.5)mm.
M,ature larva. Dorsalsurfaceofbodycoveredwith veryminutesetae; lateral
marginsofheacしthoraxandabdomenwithspinousshortsetae,butthesetaesituatedat
Fig. 8 (onp. 359). E1odes ino・,nataLEWIS,mature larva. - A, Dorsal aspect (scale: 1.0mm). -
B-F:Mouthparts(scale:0.lmm);B,labrum,ventralaspect;C leftmandible,ventralaspect;D,1eft
maxillarypalpus,dorsalaspect; E,ditto,ventralaspect;F,hypopharynx. - G-J: Abdominalseg-
ments(scale:0.5mm);G,8thtergite;H,8thsternite;I,9thtergite;J,9thsternite.