A New Diplothorax (Coleoptera, Cerambycidae) from Yunnan, Southwest China

5 Pages·1998·5 MB·English

by  Niisato, T

E、l,tra,'fok、-o,26(1):207-211,May15,1998
ANewDip1othorax:(Coleoptera,Cerambycidae) from
Yunnan,SouthwestChina
TatsuyaNIIsATo
BioindicatorCo.,Ltd.,Takada3-16-4,Toshima-ku,Tokyo, l71-0033Japan
Abstract AnewspeciesofthecerambycinegenusDip1ot11o,・a、-isdescribedand
illustratedfromnorthwesternYunnan,SouthwestChina.underthenameofD. lshiha"1ai
nov. Ilisverypeculiarinfaciesandeasilydistinguishedfromtheknowncongenersof
sp
thegenus.Thetaxonomicalimportanceofthisnewspeciesisdiscussed.
Djp1othoraxGREssITTetRoNDoNofthecerambycinetribeCleOmeniniiSapee「ly
knowngenus,andhashithertobeenknown fromonly fourspecies,vtz.,D fasciata
HoLzHcHUH(1981,pp 74-75, fig.10)andD.sangayiHoLzHCHUH(l985,pp 394-
396, fig 3) fromtheHimalayas,D.pa,-adoxusGREssITTetRONDON(1970,pp 312-
313, figs 47d,48g) fromLaos,andD. lucensHoLzHcHuH(1995,pp 28-29,fig 35)
fromSjchuan.Mostofthesespecieshavealmostcompleteelytra,butthetypespecies,
pa・ladoxus,hasstronglyreducedelytralikeaspeciesofthetribeMo1orchini.A
D.
carefulstudyofcomparativemorphologyhasrevealedthatthisgenushasacloserrela-
tjonship to P,,ocleomenesGREsslTTet RoNDoN whosemembers are widespread in
Southeast Asia.
Anaddjtiona1memberofDip1othoraxfoundintheNuJiangValleyofnorthwest-
ernYunnanofSouthwestChinawasrecentlybrought tomethroughthecourtesy of
Mr.NorioIsHIHAMAofHokkaidoUniversity.Atfirstsight,itwasfoundtobelongtoa
newspecjesbecauseofsuchpeculiaritiesasthelargebroadbodyform,withunusually
expandedpronotum,anduniqueelytralmaculation.Besides,theelytraofthisnew
speciesareintermediate in length between thoseof D. paradoxiis and threeother
knownspecies,thatis,theyarenearlyhalfthelengthofthehindbody.TheelytraofD.
pa1-adox1lswhichisthemostspecializedformarenearlytwo-fifthsthelengthofhind
body,whilethoseofratheranarchaicspeciesalmostcompletelycovertheabdominal
segments.Itisofspecialinterestthatthereductionoftheelytraexhibitsamorphocline
jnthemembersofDip1otho,・ax.Asiswellknown,thedifferenceintheelytra11engthis
regardedasoneofthemostimportantcharacterstoseparatethemembersofthetribe
Mo1orchini fromthoseoftheCleomenini inthesubfamilyCerambycinae. Themor-
phologicalgradientoftheelytrainsuchamonophyleticgroupseemstosupportmy
hypothesislhatDip1othoraxanditsrelativescanberegardedasaratherarchaic9rouP
ofthetribe Mo1orchini.
208 TatsuvaNIIsAT0
Inthe followinglines, IamgoingtodescribetheYunnanesespeciesundo「the
nameofD.js;1j;tamaisp nov.,andtobrieflydiscussonitsphylogeneticimpO「tanCe.
lwishtoexpressmydeepgratitudetoDr.Shun-IchiUENooftheNationalSci-
enceMuseum(Nat.Hist),Tokyo, forhisconstantguidanceandreadin9th「eu9hthe
orjgjna1manuscrjptofthispaper,andtoMr.NorioIsHIHAMAofHokkaidoUniVe「Sity
forhjsoffeiroftheinvaluablespecimenforthepresentstudy.
Theabbrevjationsused in thedescriptionareas follows: BL- length ofbody
fromtheapicalmarginofclypeustotheposteriormarginofanalter9iteofabdomen,
maximumwidthofheadacrosseyes,AL- lengthofantenna,FL- lengthof
Hw _
frons, FB_basal width of frons, FA -apicalwidthof frons,CL- lengthofClypeuS,
CB_basalwidthofclypeus,PL- lengthofpronotum,PA-apicalwidthofPronotum,
PB_basalwjdthofpronotum,PW-maximumwidthofpronotum,acrosslate「altu-
bercles,EL- lengthofelytra,EW-widthofelytraacrosshumeri.
fplot1lofMis加'hamalsp nov.
(Fig. l)
A largespecjes,withremarkablyexpandedpronotum,reducedelytrawhicha「e
nearlyahalfofhindbody.Colourblackanddarkreddishbrown,partlyreddishand
paleyellow,shiny;headblack,withdarkreddishbrownmouthpartsexceptforblack
mandjbular tipsandyellowishbrownpalpi; antennaeblackishbrown,graduallybe-
comjngbrownishtowardsapicalsegment;pronotumblack,withbrightreddishbrown
maculationinthecentreofbasal5/7andjustbeforebase,thebasalcollardarkreddish
brown;scutellumblack;elytrapaleyellow,eachprovidedwithdarkbrownmaculations
whosemarginsaremat-defined,1)ahumeralspotextendingtobothbasalandexternal
margins,2)anobliqueshortbandslantingfrombasal2/7ofexternalmar9intobasal
4/7ofdisc,andwidelyseparated fromsuturalmargin,3)atransversebandonapical
thjr 4)apjca1bandonapical3/14,withanteriormarginarcuatelyemarginate;hind
wings translucentblackishbrown; prosternumblack inapical3/5,bright reddish
browninbasal2/5thoughinfuscatenearcoxalcavitiesandinthecentrallineincluding
presternal process; mesosternumbright reddish brown, infuscate near centre and
mesosterna1process;mesepimeronalmostblack;metasternumlargelyblackwithred-
dishbrownsides;metepistemumbrightreddishbrown;legsblacktoblackishbrown,
midandhindfemorainthepedunclespalereddishbrown,andthesamepartof fore
femurslightlybrownish;abdomenlargelyblackishbrown.
Headrather voluminous,short,moderatelyconvex,HW/PA0.94,HW/PW0.79,
provjdedwithcoarseandratherlargepunctures,andwitherectpaleyellowhairs;frons
trapezoidal,gentlyraised,withoutamediangroove,nearlytransverseinapicalmar9in
andweaklyarcuateatsides,FL/FB0.75,FA/FB0.8;vertexstronglyconcave,provided
withdeeplongitudinal furrows,stronglyraisedtowardsantennalcavities;occiputna一「
row;eyessmall,hardlyprominent,upperlobeswidelyseparated fromlower lobes;
genaeratherdeep,3/4thedepthoflowereyelobes,bluntlyangulateventrad;clypeuS
NewDip1ot/1o,a_、-fromSouth、~,estChina 209
slightly transverse, with arcuately emarginatesides and apical margin, CL/CB 0.2;
mandiblesshort and broad, with obtuseextremities. Antennae thin andrather short,
nearly reachinghindcoxal cavities,AL/BL0.55,providedwithcoarsepunctureson
basal foursegments,clothedwithbrownishflyinghairs,andwith recumbentminute
pubescenceonapical6segments;scapeweaklyclavate,alittleshorterthansegment3
andnearlyequal inlengthtosegment4;segments3-5thickenedateachapex;segment
5aslongassegment3andslightly longer thansegment6;segments6-10moderately
compressed,andslightlydecreasinginlengthtowardsapex.
210 TatsuyaNllsAT0
Pronotum large and long, strongly dilated apicad, PL/PA 2.27, PB/PA 0.89,
PL/PW l92,PW/EW0.96,PL/EL 1.05; basemoderatelyemarginate, distinctlybor-
deredthroughout;apexsimpleandimmarginate,weaklyarcuate;sidesparallel for a
shortdistancefromapex, remarkablyswolleninapical7/l6,stronglyconstrictedat
middle,thensuddenlydivergenttothelateraltubercleswhicharestrongthoughobtuse
at extremities, andalsostrongly convergent tobasal eighth, and weakly arcuate in
basaleighth;discstronglyconvexinapicalhalfandatalevelbetweenthemiddleand
basal fourth,stronglydepressedatmiddleandbasal fourth,providedwithadeepobtri-
anglulardepressionjustbehindapexwhichisseparatedbyacentral longitudinalridge,
andwithtwopairsofoblongobliqueraisedareasonapical fourthandbasal3/8;sur-
facelargelysmooth,partlyprovidedwithpuncturesintheapicaltriangulardepression,
andbasal5/16,sparselyclothedwithyellowishbrownflyinghairs,thoughthehairsare
ratherdensenearbasal3/8.Scutellumpentagonal,convexthoughstronglydepressed
atapex,thinlyhaired.
Elytra fairly long,nearlyahalfas longashindbody,moderately narrowedto-
wardsapices,withsuturenarrowlyandarcuatelydehiscentinapical fourth,consider-
ablyexposingthesidesofmetathorax,EL/EW1.75;sidesweaklyexpandedathumeri,
almoststraightlyconvergenttoapical3/10,thenarcuatelysotoapiceswhicharecom-
pletelyrounded;discweaklyconvex,thoughdepressedatbase,nearsutureexcept for
basal3/10,andinapical fourthwhichisreflexedandmoderatelyraised;surfacevery
sparselyprovidedwithweakpuncturesandyellowishhairs.
Prosternumweakly arcuately emarginateinprofile,closely wrinkledand inter-
mixedwithcoarsepunctures,andalsowithtransversefurrowsinapicalhalf,sparsely
clothedwithpaleerecthairs;presternalprocessnarrowandstrongly compressedat
middle, formingaspoon-shapeinapicalpart.Meso-andmetathoracessparselypunc-
tured,moderatelyclothedwithpalehairs.Abdomenmoderatelyelongate,nearly7/10
ofhindbody,verysparselypunctured,sparselyclothedwithpaleerecthairs;analster-
nifewithroundedapicalmarginandweaklyproducedatmiddle.
Legsslenderandextremelylong;hindlegnearly0.75timesaslongasbody,with
femurmoderatelyclavateinapicalhalf,tibialongandgentlysinuate,firsttarsalseg-
mentnearlyequal inlengthtothefollowingtwosegmentscombined.
Bodylength13.5mm.
Typespecimen. Holotype Cheng Go, NuJiang Valley, LuShui Xian, NW
,
Yunnan,SWChina,8-VI-1989. DepositedinthecollectionoftheNationalScience
Museum(Nat.Hist),Tokyo.
Notes. Dip1otho,・ax: ishihamai sp nov. is a remarkable new species isolated
within thegenusandrather highlymodifiedlikeD.paradoxus(typespecies!) from
Laos.Thetwospeciessharesomepeculiarcharacterssuchasthereducedelytraand
expandedpronotaIapicalpart,whichareregardedasderivedfeatureswithinthegenus.
TheelytraofthethreeotherknownspeciesarenotsomuchreducedasinD. ishihamai
andD.parade)cus. Inthemostarchaicspecies,D. lucensfromSichuan,theelytraare
almostcomplete, only exposing theanal tergite. Thedilatationofpronotum in the
NewDip1olhoMxfromSouthwestChina 211
threeotherspeciesareslightlyweakerthaninD. lshihamaiandD.paradox:us.TheeX-
tensjonof abdominalsegments isalsopeculiarand isconsideredderivative in the
genusTheabdomenofD.1shihama1iselongateandnearlyequal inlengthtothatof
Dparade)als.Itjsevidentthatthisnewspeciesisclearlydiscriminatedfromtheothe「
congenersbythepeculiaritiesmentionedabove,andalsobyitslargebroadbodyand
uniqueelytra1maculation.
Theorjgjna1habitatofthisnewspeciesisunknown.Thesinglefemalespecimen
wasfortuitouslycollectedinsidearunningcarnearthev加ageChen9Gealon9theNu
JiangValleyinnorthwesternYunnan.
要 約
新里達也:中国云南省から発見されたDpi1othorax属のl新種. - Dip1othorax:属のカミキリ
ムシは, ヒマラヤから2種, インドシナから1種および中国四川省からl種の合計4種がこれま
でに知られていたが,今回,中国云南省北西部怒江流域で採集された標本に基づき,本属5番
目の種D.ishihamaispnov.を命名記載した.
本属の基準種であるD.paradoxusは鞘翅がいちじるしく短縮するコバネ型のカミキリムシで
あるが, その後に発見された3種は, 短鞘翅の傾向は認められるものの基準種ほどではなく,
腹部の大部分を覆うほぼ完全な鞘翅をもつものや短鞘翅との中問状態を示すものなど,鞘翅の
短縮に段階的な変異が認められる. 今回発見された種では, その鞘翅が既知3種と基準種のさ
らに中間的な長さをもち, この変異はほぼ連続することが明らかになった. カミキリムシの鞘
翅短縮は,族以上の高次分類に用いられることもあり,一部のグループでは重要な形質とされ
てきたが, Dip1othorax属にみられるように,単系統群のなかでも段階的に生じる変異として観
察される. その構成種の大部分が, 鞘翅が長いという理由により, ホタルカミキリ族
cleomeniniに置かれてきた本属や近緑のProcleomenes属などが, コバネ型のカミキリムシのみ
によって構成されているヒゲナガコバネカミキリ族Molorchiniにむしろ類緑が近く, その祖先
的形質を残す諸群ではなぃかとぃう仮説を, この新種の発見は支持している.
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