Table Of ContentElytra,7olkyo,24(2):l89-l95,November15,1996
ANewOculateTrechiama(Coleoptera,Trechinae) fromthe
SoutheasternPartoftheKitakamiMountains,
NortheastJapan
Shun-lobi UENo
DepartmentofZoology,NationalScienceMuseum(Nat.Hist),
3-23-lHyakunin-cho,Shinjuku,Tokyo, l69Japan
Abstract A new oculatespeciesof thetrechinegenusTli-echiama isdescribed
from thesubalpinezone ofahighmountainat thesoutheastern partof theKitakami
Mountains,NortheastJapan,underthenameofTo1lkural. Itbelongstothemeridianus
lineageofthegroupofTo,-eas,andisrecognizedatfirstsightonthelargeamplehind
bodyandtheabsenceoftheseconddorsalporeonthe3rdelytra1stria. Comments are
madeonatrechinebeetleprobablyreferabletothesamespecies,whichoccursinseveral
limestonecaveslyingnearthefootofthemountain.
The Kitakami Mountain Range, stretching fromnorth to south for more than
200kmonthePacificsideofnortheasternHonshu, isoneoftheoldestmassifsinthe
JapaneseIslands. It isakindofpeneplainandisnotparticularlyhighexcept forthe
centralpart,whichattainstoaheightof1,914m;mostmountainsontheotherparts
barelyexceed1,000mabovesea-level.Contrarytotheothermountainrangesinnorth-
easternHonshu,itiswhollynon-volcanicandaboundsinlimestonestrata,thoughthe
terrestrialcavefaunaisrelativelysimple.
Twogroupsofapteroustrechinebeetleshavebeenknown fromthismountain
range,that is,Trechiamaand Kurasawatrechus.The formeroccurseither inthesub-
alpine zoneor incaves,whilethelatter iseither cavernico1ousor upper hypogean.
MostspeciesoftheformergenusbelongtotheoreaslineageofthegroupofToreas
(UENo, unpublisheddata),but an isolatedspeciesofthemeridianuslineageoccurson
Mt.Goyo-zanandits immediatevicinitiesat thesoutheasternpartoftheKitakamis.
Theoccurrenceofthisnewspecieswaspreliminarilynoticedinapreviouspaper of
mine(UENo,1994,p 31),and Iamgoingtointroduceit intoscienceinthepresent
paper,whichisdedicatedtothememoryofthelateMr.MasafumiOHKURA.
Theabbreviationsusedhereinarethesameasthoseexplainedelsewhere.
Iamdeeply indebtedtoMessrs.HirohisaKlzAKIandYoshinariTORII,whosub-
mittedtomystudyrarecavespecimensofthenewtrechinebeetle.
l90 Shun-lobi U日、'0
Trechiama(s.str)ohkuraiS.UENo,sp nov.
[Japanesename:0hkura-naga-chibigomimushi]
(Figs.l-8)
Length:6.05-6.90mm(fromapicalmarginofclypeustoapicesofelytra).
Belongingtothemeridia,1uslineageofthegroupofTo,-eas,andrecognizedat
firstsightonthelargeamplehindbody,particularlyin d,andtheabsenceofthesec-
ondsetiferousdorsalporeonthe3rdelytra1stria.
ArelativelylargespeciessimilartoTmeridianusS.UENo(1994,p 28,figs 5-8)
in theconfigurationofheadandprothorax,butdifferent fromthelatter inthepropor-
tionofhindbodyto forebodyandinelytra1chaetotaxy.ColourasinTmeridiamis,
thoughusuallydarker,especially ontheposteriorhalfofhead,pronotum,andelytra
except forsuturalintervalsandlateralmargins.
HeadasinTmeridianus;eyessimilarlyvariableinbothsizeandconvexity,usu-
allyflatbutrarelyalittleconvex;genaethree-fifthstonine-tenths(usuallyaboutthree-
fourths)aslongaseyes,eitherstraightorveryslightlyconvex;antennaeusuallyreach-
ingbasaltwo-fifthsofelytra,sometimesalittlelongerthanthat in,3.Pronotumnar-
roweronanaveragethaninT:,nertdlanus,withthesideslessstronglyarcuatein front
andlesswidely divergentposteriad inbasal area,widest at about three-f量l hs from
base;PW/HW141-1.50(MI44),PW/PL l.10-l.19(M1.14),PW/PA t54-1.68(M
1.61), PW/PB 138-1.49 (M I 43), PB/PA 1.07-1.18(M1.13); ante-basal sinuation
distinct thoughusuallyshallow; hindanglesmoreor lesssharp inmost individuals,
sometimesnearlyrectangular;sculpturesasinTmeridia,1us.
Elytraobviouslylargerin thaninTmeridianus,thoughsimilartothelatterin
certain , usually alittle lessconvex,widestat about three-sevenths from bases;
EW/PW165-1.79(M I72),EL/EW150-1.59(M I56);striaeshallower thaninT
meridianusthoughentire,nearlysmooth;apicalstrioleusuallylessdivergentanteriad
than in Tmeridianus, gently arcuate, andusually joiningor almostjoiningstria5
throughsinuation thoughsometimesdirected tostria7; intervalsusually flatevenon
thedisc;stria3withtwosetiferousdorsalporesaf t/l2-1/10 and 3/5-2/3 frombase,
respectively;stria5alsowithtwosetiferousdorsalporesaf t/10-1/8and1/3-3/7 from
base,respectively;preapica1poresituatedonorslightlybehindtheleve1ofthetermi-
nusofapicalstriole,andevidentlymoredistant fromapexthan fromsuture;other fea-
turesas in 「 merldianus. Ventralsurfaceasin 「 meridianus.
Legsrelativelylongandslender;protibiaestraight,gentlydilatedtowardsapices,
each with a deep longitudinal groove on the external face; tarsi thin, tarsomere l
longer thantarsomeres2-3togetherbutshorter thantarsomeres2-4together inboth
meso-andmetatarsi; in d protarsomeres1and2widelydilatedandstoutlyproduced
inwardsatapices.
Malegenitalorgansmall,heavilysclerotized,similar inmanyrespectstothatof
TonicepsS.UENo(1989,p.128,figs 7-ll)oftheKamuroMountains.Aedeagusrel-
ativelyshort,aboutthree-tenthsaslongaselytra,lightlydepressed,hardlyarcuateat
NewOculateTrechiamafromtheKitakamiMountains 191
Fig. l. Trechiama(s.str)ohkuraiS.UENo,sp nov.,3,fromMt.Goyo-zanontheKitakamiMountains
192 Shun-lobiUiNo
middle,andratherabruptlybentventradatthebasalpart;dorsalmarginregularlyarcu-
ateatmiddleinprofile;basalpartlargeandshort,withlargebasalorificewhosesides
aredeeplyemarginate;sagittalaileronfairlylargebutnarrow;vieweddorsally,apical
lobesymmetrical,broadatbaseandgraduallynarrowedtowardsapex,whichissub-
truncateandobtuselytuberculateat themiddle; viewedlaterally,apical lobeslightly
curvedventracL,abruptlynarrowedbeforetheapexwhichisdorsallydenticulate;ven-
tral marginslightlyarcuateatmiddle. Innersacarmedwithacopulatory pieceand
threepatchesofheavilysclerotizedteeth;copulatorypieceaboutone-fifthaslongas
aedeagus, twisted,andwidely lamellar inapical half,withtheapical marginwidely
rounded;leftlateralteeth-patcheslooselyunitedattheproximalends,theinternalone
dorsallydilated, theexternalonenearlyhorizontal andcomposedof rather lamellar
teeth;dorso-apica1teeth-patch fairly largeandcompact.Styleslarge, leftstylelonger
andmuchbroaderthantheright,eachbearing foursetaeattheapex.
Va,-lat1on inelyt,・al c/1aetotlm. Ofthe 20specimens of the typeseries, three
(3 )areaberrantinthenumberofsetiferousdorsalporesonthe5thstria;onepos-
sessesathirdporeon the leftelytron,another possessesa thirdporeon the right
elytron,andtheother lacksthesecondporeontheleftelytron.Noaberrancyisfound
inthenumberofsetiferousdorsalporesoftheinternalseries.
Ti,pc so,-les. Holotype: d allotype: N slope, 23-VI-1967, S. UENo leg.
,
Paratypes:10 d 2 Nslope,23-VI-1967,S.UENoleg;4,3(S,1 Sslope,22-VI-
, ,
1967,S.UENoleg;1 Eridge,22-VI-1967,S.UENoleg.Alldepositedinthecollec-
,
tionoftheDepartmentofZoology,NationalScienceMuseum(Nat.Hist),Tokyo.
pe1ocali、t,. Mt.Goyo-zan, on thebordersbetween Kamaishi-shi, 0hfunato-
shiandSumita-choat thesoutheasternpartoftheKitakami Mountains,950-1,250m
in altitude on the northern slope, 1,280m in altitude on the southern slope, and
1,320m inaltitudeontheeastern ridge,in IwatePrefectureofnortheasternHonshu,
NortheastJapan.
Additionalspecimensex:amined. 1 0iwa-no-iwa-anaCave,Kamiarisu,Sumita-
,
cho, IwateProf., 5-VIII-1979, Y. TORII leg; 29 Komori-ana Cave, Kutsukake,
,
Kamigo,Tono-shi,IwateProf.,17-VIII-1983,H.KlzAKl leg;1d i Kwannon-iwa-
,
no-anaCaves(southerncave),Kutsukake,Kamigo,Tono-shi,lwateProf.,8-VII-1954,
S.UENoleg.All inthecollectionoftheDepartmentofZoology,NationalScienceMu-
seum(Nat.Hist),Tokyo.
Notes. This isadistinctivespeciesrecognizedon itsexternal features alone.
Lossoftheseconddorsalporeonthethirdelytralstriaisquiteexceptional foramem-
ber ofthe,,1eridia,1uslineage,but theclosesimilarityofaedeaga1conformationbe-
tweenthisspeciesandTonicepsfurnishesapositiveproofoftheircloserelationship.
Figs.2-8. Malegenitaliaofn,ec/1ia″ta(s.str)ohkta-a1S.UENo,sp nov;leftlateralview(2,5),apical
partofaedeagus,dorso-apicalview(3,6)、separatedcopulatorypiece、leftlateralview(4),separated
andextendedinnersacandseparatedcopulatorypiece,leftlateralview(7),andseparatedcopulatory
piece,obliqueleftdorsal view(8). - 2-4.Topotypica1specimen, fromMt.Goyo-zan. - 5-8.
Cavespecimen,fromtheKwannon-iwa-no-anaCaves.
NewOCulate「
eｽ・j am Omthe iMo tams
l93
7
8
194 Shun-IchiUENo
OnMt.Goyo-zan(1,351m inheightatthehighestpoint), thisnewspecieswas
collectedonlyinthesubalpinezoneabove950minaltitude. Iwasabletolocatethree
habitatsofthebeetle,ofwhich twowereordinary foranoculatespeciesofT,-ec;llama
but theotheronewasratherexceptional. Theordinary habitatswereonthenorthern
andsouthern slopes, onbothofwhichthetrechinebeetlewas found frombeneath
stoneslyingatthesidesofseepagesinshadedplaces. 0ntheotherhand,thesingle fe-
malespecimentakenontheeasternridgewasfoundout frombeneathastonelyingin
athicketofcreepingpine,ahabitatwhichisnotpreferredbyTt-ec;llama.
A trechinebeetleprobably referable to T o1lkulal has been known from three
limestonecaveslyingatloweraltitudetothenorthwestofMt.Goyo-zan.0neofthem
isOiwa-no-iwa-anaCaveatKamiarisu,whichisabout5.7kmdistant fromthesummit
ofMt.Goyo-zanandisabout400mabovesea-level.Theothertwo,Komori-anaCave
andtheKwannon-iwa-no-anaCaves,arelocatedatKutsukaketothenorthofOiwa-no-
iwa-anaCave;the formerisabout2.5kmdistant fromthefirst oneandliesatanalti-
tudeofabout700m,whilethelatterisabout1.3kmfurthernorthbywestandisabout
560mabovesea-level.Asisrecordedabove,onlyoneortwospecimenshavebeencol-
lectedfromeachcaveinspiteofseveralvisits,sothatthebeetlecannotberegardedas
a truecavemicole. Besides, one( )oftheKwannon-iwa-no-anaspecimenswasob-
tainedfrombeneathalargestonelyingattheentrancetothesoutherncave. Itisthere-
foremostprobablethatthebeetleiseitherendogeanorupperhypogeanatlowereleva-
tions. Thisshouldbeconfirmedby futureinvestigationsonor inthevicinitiesofMt.
Takashizu-yama,whichliesbetweenMt.Goyo-zanandthecavesatKutsukake.
Unfortunately,onlyonemaleisincludedamongthefivecavespecimensknown,
anditsgenitaliaaresomewhatdifferent fromthoseofthetypeseries fromMt.Goyo-
zan.Theaedeagusisslendererthaninthetypeseries,aboutone-thirdaslongasthe
elytra,withmoregently curvedbasalpartandlargercopulatorypiece, thelatterof
whichisabouttwo-fifthsaslongastheaedeagusandbearsadistinctdorsalcrestatthe
proximalpart; thedorso-apicalteeth-patchissmaller;andinthespecimenexamined,
anadditionalsetaexistsontheventralmarginoftheleftstyle.Thesedifferencescould
beregardedasbeingspecificorsubspecific,iftheirconstancywereconfirmed. In
ex-
ternalmorphology,however,itisperfectlyidenticalwiththespecimensofthetypese-
ries,anditslocality,theKwannon-iwa-no-anaCaves,isthe farthest fromMt.Goyo-
zan.Underthissituation,Iprefertoconsiderittorepresentanextremeofgeographical
variationofTo1tkut-a1,andtoincludeailthecavespecimensinthesamespecies.The
standardratiosofthebodypartsofthecavespecimensareasfollows: [0iwa-no-iwa-
anaspecimen] PW/HW 140,PW/PL 1.l2,PW/PA t 55, PW/PB l 47, PB/PA l.06,
EW/PW l76, EL/EW 154; [Komori-anaspecimens] PW/HW 140-1.44, PW/PL
1.18-1.20, PW/PA t 55-1.61, PW/PB 146, PB/PA l.06-1.11, EW/PW 161-1.70,
EL/EW l52-1.58; [Kwannon-iwa-no-anaspecimens]PW/HW l43 in d,1.41in
,
PW/PL1.l5in d,1.18 in ,PW/PA t58in d,1.61 in 9,PW/PB143 in d,1.44in
,
PB/PA l.11 in both and 9,EW/PW172 in d i 63 in ,EL/EW 154in d, 1.57in
NewOculateTrecilia,nafromtheKitakamiMountains 195
It isofparticular interest fromthezoogeographical viewpointthatT o1tkurai,a
member of themeridlanus lineage, is isolated at theeasternside of theKitakami
Mountains,orattheothersideofthedistributionalrangeoftheoreaslineage.Atpres-
ent,Icannotsatisfactorilyaccount fortheformationofthisdiscontinuousdistribution.
Aswasalreadypointedoutinapreviouspaperofmine(UENo,1994,p 31),themem-
bersofthemeridianuslineagearerestrictedtonon-volcanicoldmountains,whereas
thoseoftheoreaslineageusuallyoccuronrecent(oftenPostglacial)volcanoes.This
seemstomeanthat thespeciationoftheformer tookplacemuchearlier thanthatof
thelatter.However, theKitakami Mountains,oneoftheoldestmassifsinJapan,are
exceptional tothisgeneralization,sincetheyaremostlyoccupiedbythemembersof
thelatterlineageincludingatleasttwocavespecies. ItispossibletoregardTohkurai
asarelictofanoldfauna,mostofwhichwerealreadyreplacedbynewcomers,butthis
isjustapossibilityandneedsfurtherinvestigationsforverification.
ThisinterestingnewspeciesisdedicatedtothelateMr.MasafumiOHKURA,who
unexpectedlypassedawayonAugust21, l995,attheageof80,fromaftereffectofthe
terribleshockcausedbytheHanshinEarthquakethathaddestroyedhishomeonJanu-
ary17ofthesameyear.0HKuRAwasapioneeramateurcarabido1ogistinJapan,taught
metherudimentsofcarabidtaxonomywhenIwasaschoolboy,andwasagoodfriend
ofmineeversince(cf.UENo, l995,p.1).
要 約
上野俊一:北上山地南東部に隔離されたナガチビゴミムシ属のl新種. - 北上山地南束部
の五葉山とその北西部に位置する3カ所の石J火洞から, 有眼のナガチビゴミムシの一種を記般
し, オオクラナガチビゴミムシTrechiamaohkuraiS.UI_NOと命名した. この種は, 奥羽山脈から
白神山地にかけての, 非火山性地域に広く分布する, マヒルナガチビゴミムシ亜群に属するが,
体の後半部がとくに雄で大きいことと, 上翅第3条の第2孔点を欠くこととで, ほかの種から
容易に区別できる. イワキナガチビゴミムシ亜群の種が広く分布する北上山地の一部に, この
ような別亜群の種が局在することは, 生物地理学的にみてたいへん興味深い. なお, 新種名は,
昨年の8月に急逝された大倉正文氏に捧げたものである.
References
UENo,S.-I., 1989. NewoculateTrechia″Ia (Coleoptera,Trechinae)fromMiyagiPrefecture,Northeast
Japan. Elytra,「okyo,17:l23-133.
- 1994. Newoculate n・,echiama(Coleoptera,Trechinae)mainlyfromnon-volcanicmountainsof
northernHonshu,NortheastJapan. Ibid.,22:23 'l1'.
- 1995. Haifacenturyofsubterraneanexplorations. Spec.Bull.Jpn.Soc.Coleoptero1.,「okyo,
(4):1-30.
