A New Species of the Genus Coryphium (Coleoptera, Staphylinidae) from Hokkaido, Japan

2007·6.3 MB·English

by  Watanabe, Y

Elytra,Tokyo,35(1):299-304,May30,2007
A NewSpeciesof theGenusCoryphium (Coleoptera,
Staphylinidae) fromHokkaido,Japan
Yasuaki WATANABE
Laboratoryof InsectResources,TokyoUniversityofAgriculture,
Atsugi, Kanagawa,243-0034Japan
Abstract AnewspeciesofthestaphylinidgenusCoryphiumisdescribedunder
the name of C yasuda1. It is obtained by sifting dead leaves accumulated in a
coniferousforestonMt. KurodakeoftheDaisetsuMountainsin Hokkaido,Japan.
FourspeciesoftheCoryphiumatratumgroup(ZERcH,1990,p 33) havehitherto
beenreported fromthePalearcticRegion(LOBL&SMETANA,2004,p 254). Through
thecourtesy of Mr. Nobuki Yasuda, I hadan opportunity toexaminean interesting
species,whichwasobtainedonMt. KurodakeoftheDaisetsuMountainsinHokkaido,
Japan. Thisspeciesseemstobeplacedin thegroupofCoryphiumatratuminviewof
havinglargehead,similarconfigurationoflabrumandabdomenprovidedwithapairof
minutepruinosespotsatthemiddleofthe4thtergite. Afteracloseexamination, ithas
becomeclear that thisspecies isnew toscience for reason of disagreement with the
knownmembersofthisspecies-groupinantennalarticulation,obscurecrenulationon
lateral margins of pronotum and configuration ofmalegenital organ. It will be
describedinthispaper. Thetypeseriesofthenewspeciesisdeposited in thecollection
oftheLaboratoryofInsectResources,TokyoUniversityofAgriculture.
Before goingfurther, IwouldliketoexpressmydeepgratitudetoDr.Shun-Ichi
UENo,VisitingProfessoratTokyoUniversityofAgriculture,forhiskindadviceonthe
presentstudy. MyheartythanksarealsoduetoMr.NobukiYAsUDA,SounkyoVisitor
Center, for his kindness in providing with the invaluablespecimensused in this
me
study, and toMr. Junnosuke KANToH, Laboratory of Insect Resourcesof Tokyo
UniversityofAgriculture, for takingthephotographinserted in thispaper.
CoryphiumyasudaiY.WATANABE,sp nov.
[Japanesename:Zubiro-chibi-yotsume-hanekakushi]
(Figs.1-10)
Body length: 2.2-2.6mm (from front margin of head toanal end); 1.6-1.9mm
(fromfrontmarginofheadtoelytra1apices).
Body nearly spindle-shaped and somewhat depressed above. Colour black and
shining, with mandibles yellow, palpi, antennae and legs reddish brown, labrum and
300 Yasuaki WATANABE
・f.l-,1,・11:・
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' . - 一
Fig.1. Coryphiumyasuda1Y.WATANABE,sp nov., .Scale:1.0mm
elytradarkbrown,epipleuraofpronotumandelytradarkyellowishbrown.
Male. Headsomewhatdepressedaboveandsubtrapezoida1,morestronglynar-
rowedanteriadthanposteriad,apparentlywideracrosscompoundeyesthanlong(width
/ length=1.35); postocular part arcuate and slightly shorter than the longitudinal
diameter of each eye (posterior part/longitudinal diameter of eye=0.88), which is
somewhatprominentlaterad;surfacemoderatelyclosely,coarselypuncturedandfinely
pubescent though without groundsculpture, distancebetween puncturesequal toor
slightlylargerthantheirdiameter,providedwithadepressiononeachsideofthemiddle
behindeachantennaltubercle;ocelliminute,thedistancebetweenthemlargerthanthat
fromtheoutsideofocellustotheinnermarginofeachcompoundeye. Mandibles
slenderandstronglycurvedinwardsinapicalhalves,molarareaobscure;eachmandible
armed with an acutetooth at themiddleof inner margin, theright toothsomewhat
broader than left tooth. Maxillae relatively narrow; galeasomewhat broader than
1aciniaandnarrowedapicad,closelyfringedwithshortbristlesattheapicalpart;1acinia
NewCoryphiumfromHokkaido 301
5
Figs2-5. Mouth-partsofCoryphiumyasuda1sp nov;mandibles(2),maxilla (3), labrum (4)and
labium(5).Scale:0.1mm
abruptlynarrowedapicadinapical fourth, innermarginprovidedwithfinebristles in
apicalfourth;maxillarypalpusfour-segmented,1stsegmentminute,2ndstronglydilated
towardstheapex,morethantwiceaslongaswide,3rdmarkedlyswollen,wider than
long(width/length=1.10),alittlelonger(3rd/2nd=1.25)andremarkablywider(3rd/
2nd=2.89)than2nd,4thsubulate,distinctlylongerthanwide(length/width=3.0),but
muchshorter (4th/3rd=0.30) andconspicuouslynarrower (4th/3rd=0.09) than3rd.
Labrumapparentlytransverseandstronglynarrowedtowardsbothanteriadandposte-
riad,anteriormarginfeeblyemarginateat themiddle, lateralsidesarcuatethroughout
its whole length; surface fringed with a number of long seta on ante-lateral part,
Mentumtransverseandsubtrapezoida1,abruptlynarrowedinanteriorthird,lateralsides
arcuateinposterior three-fourthsandnearlystraight inanterior fourth,providedwith
arelatively longsetaateach lateralsidebeforeposteriormargin; ligulamembranous,
deeplynotchedat themiddleofanteriormarginand formingtwo lobes; labial palpus
three-segmented, 1st the longest, morethan t5 timesas longaswide, 2ndabout 15
302 Yasuaki WATANABE
7
Figs 6-7. Last two abdominal sternites in maleof Coryphiumyasuda1sp nov; 8th abdormina1
sternite(6)and9thabdominalsternite(7). Scale:0.1mm
timesas longaswide,butdistinctlyshorter(2nd/1st=0.67)andsomewhatnarrower
(2nd/1st=0.72)than1st,3rdtwiceaslongaswide,almostequalinlengthtothougha
littlenarrowerthan2nd,narrowlyroundedattheapex. Antennaeelongate,extending
slightlybeyond theposteriormarginofpronotum, threeor fourproximalsegments
polished, theremainingsopaque,1stsegmentrobustandwidenedapicad,1.5tjmesas
longaswide,2ndconstrictedatthebase,1.5timesaslongaswide,muchshorter(2nd/
1st=0.67)andnarrower(2nd/1st=0.67)than1st,3rdsomewhatdilatedapicad,much
Ion9er thanwide(length/width=1.84),alittlelonger (3rd/2nd=1.17) butslightly
narrower (3rd/2nd=0.95)than2nd,4thto6thequalinbothlengthandwidthtoone
another,eachdistinctlylongerthanwide(length/width=1.43),butsomewhatshorter
(eachof4thto6th/3rd=0.71)andslightlynarrower(eachof4thto6th/3rd=0.92)
than3「d,7thto11thgraduallyincreasinginwidth,7thsomewhat longer thanwjde
(1en9th/width=1.25), aslongasandslightlywider (7th/6th=1.14) than6th,8th
Sli9htly1ongerthanwide(length/width=1.ll)aslongasandsomewhatwjder(8th/7th
=1.13)than7th,9thsomewhatlongerthanwide(length/width=1.20),alittlelonger
(9th/8th=1.20)andslightlywider(9th/8th=1.11) than8th,10thsomewhat longer
thanwide(fen9th/width=1.13),aslongasandslightlywiderthan9th(10th/9th=
1・06),11thmorethantwiceaslongaswide,twiceaslongasandslightlywider(11th/
10th=1.04) than10th,subacuminateattheapex.
P「onOtumconvexmediallyandtransverse(width/length=1.29),nearlyaslongas
andalmostequaltohead,widestatanteriorthirdandmorestronglynarrowedposterjad
thananteriad; lateralsidesfinelyborderedandperceptivelycrenulate,stronglyarcuate
inante「Oi 「halvesandalmoststraightinposteriorhalves,anteriormarginemargjnateat
themiddle,posteriormarginnearlytruncate,anterioranglesrounded,posterjorones
「eCtan9ularthou9hbluntatthecorners;surfaceslightlymorecloselyandmorecoarsely
PunCtu「ed than in head, providedwithaU-shapeddepressionat themiddlebefore
NewCoryphiumfromHokkaido 303
/
-
-
.,..l-.・・一.--・・・・
8 10
Figs 8-10. MalegenitalorganofCoryphiu1r1yasilda1sp nov;dorsalview (8), lateralview (9)and
ventralview (10).Scale:0.25mm.
posteriormargin,anarrowandlongitudinaldepressionat themiddleinanterior half,
andashallowdepressioninsideeachlateralside. Scutellumminuteandsubtriangular,
surface impunctate thoughcovered with very fine coriaceousgroundsculptureonly
visibleunderhighmagnification. Elytratrapezoidalandsomewhatdilatedposteriad,a
littlelonger thanwide (length/width=1.09), apparently longer (elytra/pronotum=
2.12) and15timesaswideaspronotum,lateralsidesalmoststraight,posteriormargin
nearlytruncate,posterior anglesbroadlyrounded;surfaceclosely,coarselypunctured
andprovidedwithsimilarpubescenceasonpronotum. Legsmoderatelylong,protarsus
notwidened,lastsegmentofmetatarsusalmostaslongasthetwoprecedingsegments
together.
Abdomen relativelybroad,gentlynarrowed from3rd to5thsegment,andthen
abruptly narrowed towardstheanalend;surfaceofeach tergitemoderatelyclosely,
superficiallypuncturedandcoveredwithmicroscopiccoriaceousgroundsculptureand
finepubescence,4thtergitewithapairofsmallpruinosespotsatthemiddle;8thsternite
broadly and shallowlyemarginateat themiddleof posterior margin, 9thsternite
spatulate,graduallydilatedtowardsthebroadlyroundedapex.
Genitalorgantrilobedandsymmetrical. Medianlobeelongate,graduallynarrowed
posteriadinbasaltwo-thirdsandthenabruptlysotowardsthepointedapexseen from
thedorsalside,stronglycurveddorsadinapicalpart inprofile. Paramereseton9ate,
almostaslongasmedianlobe,eachslightlywidenedbeforetheapexwhichisnarrowly
rounded.
Fem ale. Similar ingeneralappearancetomale,butdifferent fromit inthe8th
abdominalsternitenarrowly roundedat theapex.
Type series. Holotype: , allotype:早, Kumono-daira, Mt. Kurodake of the
304 Yasuaki WATANABE
DaisetsuMts.,Hokkaido,Japan,1-IX-2005,N.YAsuDAleg.Paratypes:2 3早早,
,
samedataas for theholotype.
Distributzon. Japan (Hokkaido).
Remarks. This new species issimilar inbodysizeand facies to C nataliae
SHAvRIN(2001,p. 192) fromEastSiberia,but differsfromthelatter in thefollowing
points:Thirdantennalsegmentdistinctlylongerthanthe4th,and8thto10thsegments
eachlongerthanbroad;pronotummoretransverse(width/length=1.35);elytranotso
long(length/width=1.09)asinCnataliae,muchmorecloselyandcoarselypunctured
andmedian lobeofmalegenitalorgandistinctlynarrowedtowards thepointedapex.
Bionomics. Allthespecimenswereobtainedbysiftingdeadleavesaccumulatedin
aconiferous forest,Pinuspumila,onMt. Kurodakeof theDaisetsuMountainsatan
altitudeof1,900m.
Etymology. Thespecificepithet of thisnewspecies is givenafter Mr. Nobuki
YAsUDA, whocollectedthetypeseries.
要 約
渡辺泰明:北海道で採集されたズビロチビョツメハネカクシ属(甲虫目,ハネカクシ科)の1新
種. - Coryphiumズビロチビョツメハネカクシ属 (新称) は, ヨツメハネカクシ亜科のズビロ
ヨツメハネカクシ族Coryphiiniに含まれ, 旧北区に分布しているが, これまで日本からの記録は
なかった. 最近, 私は保田信紀氏 (層雲峡ビジターセンター) のご厚意で, 大雪山黒岳のハイマ
ツ帯の落葉から採集された微小なハネカクシを検討する機会を得たが, この種はCoryphium属の
Catratum種群に属する種と考えられた. そして, 体長や外部形態が東シベリァから記載された
CnataliaeSHARvINに類似しているが,角?角の第3節が第4節より明らかに長く, また第8節一
10節の各節が幅より長いこと,前胸背板の形状や点刻, さらに雄交尾器の形状も異なることで未
記載種と判定し, Cyasudai (ズビロチビョツメハネカクシ) と命名・記載した.
References
LOBL,1.,&A.SMETANA,2004.Staphylinoidea.CatalogueofPalaearcticColeoptera11. Hydrophi1oidea-
Histeroidea-942pp.ApolloBooks,Stenstrup.
SHAVRIN, A. V., 2001. New and little-known species of Omaliinae from the Baikal-Transbaika1 area
(Coleoptera:Staphylinidae).ZoosystematlcaRossica,9:189-193.
ZERCHE,L.,1990.MonographiederPalaarktischenCoryphiini(Coleoptera,Staphylinidae,0maliinae).413
pp.AkademiederLandwirtschaftswisse haftenderDeutschenDemokratischenRepublik,Berlin
1993.Ditto.Supplementum1.Beitr. Ent., Berlin,43:319-374