A remarkable new species of the genus Necydalis (Coleoptera, Cerambycidae) discovered in southern Vietnam

2008·3.6 MB·

by  Niisato, Tatsuya

Elytra,Tokyo,36(1):19-24,May30,2008
A RemarkableNewSpeciesof theGenusNelyda11s (Coleoptera,
Cerambycidae) Discovered inSouthernVietnam
TatsuyaNnsATo
BioindicatorCo., Ltd.,Yarai-cho126,Shinjuku,Tokyo,162-0805Japan
Abstract AnewspeciesofthegenusNecydalisisdescribedfromMt.Brianof
southern Vietnamunder thenameof N.(Necydalis)meridionalissp nov. The new
specieshasclose relationship to the members of the N esaki1group,andmaybe
consideredasa highlyspecializedspeciesin the group. Mt. Brian of LamDong
Provinceisthesouthernmostlocalityof thegenusNecydalisinIndochinaandabout
300km distant to thesouth from Mt. Tam Daoof VinhPhuProvince, analready-
knownlocalityof thegenus.
Thirteenmembersof thegenusNecydalisareknown from Indochinaand all of
them were rather recently recorded in thepast twenty years (HoLzscHUH, 1989;
TAKAKUwA &NIIsAT0, 1996; TAKAKUwA, 1997; NIISAT0,1998a, b; NIISAT0&N.
OHBAYAsHI,2003,2004). Theknownrangeof thegenusinIndochinaisrestrictedto
northernareas,andnonehavesofar beenrecorded fromthesouthofabout20° N in
latitude.
InthecourseofstudyingthenecydalinefaunaofIndochina,I foundaremarkable
new species recently collected from Mt. Brian of Lam Dong Province, southern
Vietnam. Thoughit isquitepeculiar in faciesunlikeanyother membersof thegenus,
itmayhavesomerelationshiptothemembersoftheNesakiigroup. Mt.BrianofLam
DongProvince,thetypelocalityofnewspecies, isthesouthernmostknownlocalityof
thegenusNecydalisinIndochinaandabout300kmdistanttothesouth fromMt.Tam
DaoofVinhPhuProvince,whichisthealready-knownlocalityofthegenusinVietnam.
Inthefollowinglines,Iwilldescribeitunder thenameofN meridionalissp nov asthe
first representativeof thegenusfromsouthernareaofIndochina.
I wish toexpressmy hearty thanks to Dr. Shun-Ichi U直NO for his continuous
guidance, andalsotoMessrs.ShigeoTsUYUKIandAkiraYAGIsHITA fortheirkind
arrangement toobtainthetypeseriesof thenewN:ecydalisspecies.
Necydalis (Necydalis)meridionalissp nov.
(Figs.1-7)
Body length 19.2mm in 23.0mm in 早 (from apical margin of clypeus to
,
abdominalapex). Slenderandmedium-sizedspeciesof infuscatebodyprovidedwith
20 Tatsuva NIIsATo
goldenyellowpubescenceatsidesofthoraces.
M ale. Colour black in head and thoraces, brown in abdomen, weaklyshiny;
elytrablack,darkyellowishbrowninbasal fourthandalongbasal2/5nearsuture;hind
wingstranslucentblackishbrown;mouthpartslightyellowishbrown,blackishinclypeus
except for yellowishapicalpart ofapical lobe,mandiblesblackishbrown;antennae
black,thoughslightlybrownishinbasal threesegments; legsbrowntoyellowishbrown,
blackishintarsi,mostofhindtibiaexceptforthebase,uppersidesofmidtibiaandhind
femurslightlyinfuscate.
Head relatively voluminous,moderatelyconvex, 1.25timesaswideasapicalor
almost equal to themaximum width ofpronotum,strongly and closelypunctured,
clothedwithpaleyellowhairs,partlywithgoldenyellowpubescentmaculationat the
middleof fronsand temperabehindeyes; fronsquadrate, as longaswide, strongly
convexinobliquelinefrombasalcorner tothemiddleofapicalmargin,markedlyand
triangularlydeclivoustowardsadeepmediangroove,thegrooveextendingfromapical
marginof fronstotheendofocciput, withapicalmargintriangularlyconcavebyvery
deepsuture;clypeuswithbasal lobetransversetriangular,moderatelyconvex,smooth
onsurface, apical lobe trapezoidal, nearly ahalf of thebasal width,slightly raised,
scatteredwitha few largepunctures; genaemoderateindepth,4/9thedepthof lower
eye-lobes; vertexandocciputmoderatelyconvex,coarselyshagreened, ratherdistinctly
raisednearantennalcavities;temperahardlyproduced,attainingexternalsixthofeye;
eyesdistinctlyprominentthoughdeeplyemarginate,separatedfromoneanotherby4/9
thewidthofocciputor4/5thewidthofeachlobe. Antennaeslender thoughwidened
inmiddlesegments,reachingthebaseoftergite5,coveredonlywithdenseminutepale
pubescence;scaperoundedquadrate,slightlydepressed,4/5thelengthofsegment3,
segments 3and 4 very weakly thickenedapicad,segment 43/4 thelength of the
preceding,segments5-7broadenedanddistinctlydepressed,segment8weaklyso,apical
threesegmentsalmostcylindrical.
Pronotum moderate in length, as long as themaximum width between lateral
tuberclescr t十1/4thewidthofapex,alittleshorter thanelytra,slightlybroadened
basad;sidesmoderatelyarcuatenearmiddle, withconspicuousbutsmall tuberclesat
basal5/12,gentlyarcuatenearapicalandbasalthird,clothedwithdensegoldenyellow
pubescencethroughout;disclargelyconvexinbasal3/4,onwhichlargecallositybefore
basal fourth is indistinctlydivided inapical2/5, transverse raisedareabeforebasal
margin,shagreenedanddenselyclothedwithbrownpubescence,thoughalmostglabrous
andwithafewcoarsepuncturesonthecallosity.Scutellumroundedtriangular,concave
along themedianline, coarselypunctured,thinlypubescent.
Elytraas longaswide, widelydehiscent inapical3/4, thicklymargined along
suture;sideswithdistinctlyprominenthumeri,weaklynarrowedinalmoststraightline
toapiceswhicharecompletelyroundedatexternalanglesbut roundlyangledatsuture;
disc moderately convexandstronglyuneven, obliquely raised fromhumeri to apical
3/8,thickened inapical fourth,stronglydepressedon theother parts,strongly and
coarsely punctured in most areas, sparsely scattered with pale yellow hairs, short
RemarkableNecvdalisfromSouthernVietnam 21
、 '
2
Figs.1-2. Mecy a11s (Mecydafls) merfd1o,faffssp nov from Mt. Brian of Lam Dong provjnce,
southernVietnam. - 1,Holotype ;2,allotype♀.
brownishpubescencenearapicesandalsodensegoldenyellowonenearscutellum. Hind
wingsattainingto theapexoftergite5.
Prosternumweaklyconcaveinprofileandcoarselyrugoselypuncturedonsurface
before coxal cavities, scattered with golden yellow hairs, with strongly compressed
intercoxa1process. Meso-andmetathoracesdeeplycloselypunctured,denselyclothed
with golden yellow pubescenceonmesepimeron, metasternumexcept for middle of
22 Tatsuva NllsATo
sides,apicesofmetepisternumandmetepimeron. Abdomenlongandveryslender,2/3
thelengthofbody,almostsmoothandsparselybrownishhaired;ventrite1alittlemore
than t/4thelengthofabdomen,quitecylindrical,ventrite4rather distinctlydilated
apicadandaslongasthepreceding;analventritewithsidesstraightlydilatedtomiddle
thenratherweaklyarcuatetoapex,withdiscdeclivoustowardsmid-linejust behind
base,graduallydeeptowardsapicalmarginwhichiswidelytriangularlyconcave;tergite
81十1/3thelengthofthebasalwidth,weaklynarrowedtoapexwhichisgentlyarcuate.
Legs longandmarkedlyslender, thinlypaleyellowhairedon femoraandtibiae;
hindfemurmoderatelyswolleninapical2/5whichisdistinctlycompressed;hindtarsus
hardly thickened, with 1st segment 7/10 thelength to the following twosegments
combined.
Malegenitalorgan. Medianlobealittlelongerthananalventrite,ratherweakly
arcuateinprofile,weaklyconvexevenatthebaseofapicallobe,bluntlypointedatapex,
withdorsalplatealittleshorterthanventralplate,narrowlytruncateatapex. Tegmen
slender,slightlylonger thanmedianlobe;paramere5/8thelengthoftegmen,dehiscent
inapical4/5,almostparallelatsides, thoughslightlynarrowedfrommiddletoapex,
denselyprovidedwithshortsetaenearapices.
Female. Similar tomale,thoughbodyfairlybroadandnotsoslender. Colour
almost asin ,thoughelytraexcept for themarginsarelargelydarkyellowishbrown,
antennabrowninbasal foursegments, infuscateonuppersidesofsegments5-7and
almost black in apical four segments, hind tarsusentirely light yellow. Antennae
reaching the base of tergite 4, with segments5-9slightly broadened andweakly
depressed. Elytra a little longer than wide. Abdomen with anal ventritesimply
flattened. Hindtarsusmoderatelybroadened,withsegment1morethantwiceaslong
asthefollowingtwosegmentscombined.
Typeseries. Holotype Mt.Brian,1,600m inalt., nearBaoLoc, LamDong
,
Prov.,S.Vietnam,1~10-V-2006. Allotype早,samelocalityastheholotype,19-III-
2004. TheholotypeispreservedinthecollectionoftheNationalMuseumofNatureand
Science,Tokyo,andtheallotypeisintheprivatecollectionofNIIsATo.
Distribution. SouthernVietnam.
Notes. No〔:ydalismeridionalissp nov. isaremarkablypeculiarspeciesinhaving
Veryslender infuscatebodywithlongandslender legs,andlargelygoldenpubescent
Sides of thoraces, and easily distinguishedby thegeneral appearance to theother
membersofthegenus. Trueaffinityofthenewspeciesseemsuncertainforthereason
ofitsexternalpeculiarity.Consultingwiththemaleabdomenandthegenjta1organ,the
newSpecieshascloserrelationshiptothemembersoftheNesakiigroup;theshapeand
Concavityofanalventrite, thesimplyarcuatemedianlobewiththenarrowlytruncate
apexofdorsalplate,andtheslenderparallel-sidedparameres,arealmost identicalwith
thoseofN esakii MIWAet MIToNo from Taiwan or N choul NIIsATo fromGuangxj
ofthesamespecies-group. Ne、tydalismeridionalissp nov maybeahighlyspecialized
Speciesof thesamelineageoftheN esakii groupinsouthernareaofIndochina.
Mt.BrianofLamDongProvinceislocatedjustsouthof12° Ninlatitudeandis
Remarkable NecvdalisfromSouthern Vietnam 23
Fjgs 3-7. Genitaliaandanal ventriteofmaleofNecydalis (Necydalis)meridionalissp nov from
Mt. Brian of LamDongProvince,southernVietnam. - 3, Median lobeand tegmen,lateral
vjew;4,medianlobeindorsalview;5,tegmenindorsalview;6,analventriteinventralview,
showingtheconcavity;7, tergite8indorsalview.
about 300kmdistant to thesouth from Mt. Tam Dao, which isthemost approximate
localityofthegenusNelcydalisinIndochina.Aswaswritteninintroduction,nomembe「
ofthegenushassofarbeenrecordedfromthesouthof20° NinIndochina. DSiCOVe「y
ofaNecyda11sspeciesfromsuchlowerlatitudeassouthernVietnamisveryinterestin9
jnzoogeographicalpointofview,andsomeunknownmembersofthegenuswillbe
found fromthewjdeblankareaofdistributionbeyond300kmineastern Indochinaby
24 TatsuyaNIIsAT0
further fieldsurvey.
EcologicaldataofN meridionalissp nov. isquiteunknownsinceIwasunableto
receiveany informationfromthecollectors. Thepairofthetypeserieshavedifferent
datalabelsseparatedinMarchof2004andMayof2006,andmaybecollectedonflight
oncertainpeakofMt.Brian.
要 約
新里達也: 南ベトナムから発見されたホソコバネカミキリ属の1新種. - インドシナでは,
過去20年間の比較的新しい時代に, 13種に及ぶホソコバネカミキリ類が次つぎと発見されてき
たが, それらはいずれも北部山岳地に限られ,およそ北緯20度以南の地域からは本属のいかなる
種も知られていなかった. 最近になって, 既知の分布地からはるか南に位置する, 南ベトナムの
ラムトン県から本属の基亜属に含まれる顕著な1新種が発見されたので, 本論文においてNecy-
dalis(Necydalis)meridionalisspnov.と命名し記載した. 本種は, きわめて特異な外観をもち, 基
亜属の既知種とは容易に識別ができるが, 基本的な体の構造や交尾器を含む雄の二次性徴から判
断するかぎり, おそらくェサキホソコバネカミキリ種群の種に近いものではないかと考えられ
る. なお, 基準産地のブライァン山は, ホソコバネカミキリ類の既知産地としてはもっと近いビ
ンフ一県のタムダオ山から直線距離でおよそ300km南に位置し, 本属の中心的な分布域からも
遠く隔離されている. このような低緯度地域から本属が発見されたことは生物地理学的にみて非
常に興味深いが, いっぼう,北緯12~20度にわたるこの広大な分布の空白地帯も,本属の未知の
種が生息することは十分に予想され, 今後の調査によるさらなる新発見が期待される.
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