Taxonomic Notes on the Tribe Mecysolobini (Coleoptera, Curculionidae), with Descriptions of Three New Taxa from Japan

2007·13.5 MB·English

by  Morimoto, K

Elytra,Tokyo,35(1):226-237,May30,2007
Taxonomic Noteson theTribeMecyso1obini
(Coleoptera,Curculionidae),with
DescriptionsofThreeNewTaxa fromJapan
Katsura MoRIMoTo
20-101Natadanchi,Higashi-ku,Fukuoka,811-0205Japan
and
HiroakiKoJIMA*
TheKyushuUniversityMuseum, KyushuUniversity,Fukuoka,812-8581Japan
Abstract AkeytogeneraandsubgeneraofthetribeMecyso1obiniiSprepared
asatemporarycompilation fromHELLER(1918), PAJNl &DHIR(1987)andVoss
(1956-62) for aimingtoclarifythesystematic position of the newsubgenus Mp-
ponomerus. PseudmesatcidodesPAJNlet DHIR, 1987, isnewlysynonymized with
SternuchopsisHELLER,1917,becauseofthesimilarityof theirtype-species:pectoralis
and waltoni. A new subgenusand two new species are described in the tribe
Mecyso1obini: Neomecys1obus (Nipponomerus subg. nov), Neomecys1obus (Nip-
ponomerus)masatakaisp nov., type-speciesof thesubgenus, fromJapan(Ryukyus:
Amami-0shima,Ishigaki-jimaandYonaguni-jimaIsis),andMerus(Merus)unita(sc1-
atus sp nov from TaiwanandJapan (Ryukyus:Okinawa-hontoandIshigaki-jima
Isis). AlistofJapanesespeciesisgivenwiththreenewcombinations:Neomecys1obus
(Nippono,rlerus) nigrofasciatus (KONo),comb nov. [Alcides],Cylindratcidestaka-
hashii (KONo), comb nov. [Alcides], and Sternuchopsls (Mesalctdodes) trifidus
(PAscoE,1870),comb nov. [Alcides].
ThetribeMecyso1obini (formerAlcidinaeorAlcidodinae) includesmanycharac-
teristicweevilswithbeautifulmarkingsandisrather well-knownat thespecies level
(HAAF,1960-1964,etc.),butisconfusedonthetaxonomyatthegenericandsubgeneric
levelsmostlyduetotheproposalofhighertaxafor thelimitedspeciesandpartlydueto
theignoranceoftheInternationalCodeofZoologicalNomenclaturebyseveralauthors.
HELLER (1918) first attempted todividethegenusAlcidesintosixsubgenerawithout
designationofthetype-species. Voss(1956-1962)proposed four taxafragmentarilyin
severaldifferenttypesofclassification,butHAAFignoredthesesubdivisionsinhisseries
*Present address: Laboratory of Entomology, Faculty of Agriculture, Tokyo University of
Agriculture, Funako1737, Atsugi, Kanagawa,243-0034Japan.
NotesontheTribeMecyso1obini 227
ofregional revisionsandplacedallspeciesinAlcidodes,anapparentjuniorsynonymof
Mecyso1obus, in disregardof theruleofpriority, anddivided theAfricanspeciesinto
four groups. PAJNI & DHIR(1987) revised thehigher taxaupon Indianspecies, but
theirworkincludedmanyerrorswhenviewedfromtheCode. Namesofthehighertaxa
sofarappeared in literaturewerecorrectedandenumeratedbyALoNso-ZARAzAGA &
LYAL (1999) by dividing the tribe inte l9 generic group taxa. This treatment is,
however, apparently insufficient for thesystemof thetribeMecyso1obini andmany
species-groupsmay be remainedoutsidethesystem, as LYAL (l996) and LYAL&
CuRREN(2000)pointedoutandclaimedtheneedof therevisionofhigherclassifica-
tion. Theseauthors,however,evadedtheproblemandrevisedtheseed-infestingspecies
all inAlcidodesintheexcusebyadoptionof themerelymostcommonlyusedname.
When our study on the higher taxa of the tribe Mecysolobini was initiated,
MasatakaSAT0showed aspecimenofdoubtfulposition in1963 to theseniorauthor,
which wasunique inhavingsimpleclawsandbroad intercoxa1distances inpro-and
mesosterna. Itsdescriptionhasbeenwithheldbecauseof theinsufficiencyofmaterials
forcomparison,butnowanewsubgenusisdecidedtobeproposeduponthisspeciesfor
the commemoration of the late Dr. Masataka SAT0 for his great contributions on
entomologyandtothememoryofourmutual friendshipoverhalfacentury.
Beforegoingtothedescriptionofthissubgenus,atemporarykeytothegeneraand
subgeneraiscompiledupontheavailablematerialsandliteraturebyselectingcharacters
followingmostlyafterHELLER(1918),Voss(1956-1962),andPAJNI&DHIR(1987),
andthesystemisalittledifferent fromthatofALoNso-ZARAzAGA& Lya1(1999). The
key wepresent herearenewly adoptedsomeundersidecharacters, but isapparently
insufficienttocoverthewholespeciesinthetribe,becausemanyspeciesmayremainnot
keyedoutintoanyofthehigher taxa,or thekey-out taxamayincludeheterogeneous
species. We,however,hopethatthekeywillgiveacluetoinitiatefurtherstudy forthe
taxonomistswhentheyfeeltheproblems. Inthefollowingkey,Ments(Indomecys1obus)
PAJNI et DHIR, 1987, M. (Pseudalcicodes) Voss, 1962andSternuchopsis (Robusta1-
cides)HELLER,1918arenotincludedsincetheventralcharactersarenotavailablefrom
theirdescriptions.
Temporary Key toGeneraandSubgeneraoftheTribeMecysolobini
1(2) Tarsalclawsfree,simple;pronotumwithoutocular lobes;secondventriteas
longasfirstandaslongasthirdandfourthcombined;antennaewith funicle
sharplyseparate fromclub .A1cidodoplesiusVoss,1960
2(1) Tarsalclawsconnateatbase,bifidinmostspecies;pronotumwithocularlobes;
secondventritealmostaslongasorslightlyshorter thanfirstbehindcoxa,
slightly longer than third.
3(4) Clawsegmenthardlycomingout fromthirdsegment;antennal funiclerobust,
secondtoseventhsegmentstransverse,successivelybecomingwider,second
segment almost as long as third,seventh narrower than the first of club;
228 Katsura MoRIMoToand Hiroaki KoJIMA
procoxaelyinginthemiddleofprosternumbetweensubmarginalsulcusand
posteriormargin;metasternumbetweenmeso-andmetacoxaemuch longer
than mesocoxa BrahmalcidodesPAJNI et DHIR, 1987
4(3) Clawsegmentprojectingmoderatelyorhighlyout ofthirdsegment;thelatter
deeplydaft beyondthemiddle
5(8) Metasternumproduced tubercle-likeor triangular towardshindcoxae.
6(7) Seventhfunicularsegmentnarrowerthanfirstofclubandseparatedfromclub
Tubercu1omecys1obusPAJNI et DHIR,1987
7(6) Seventh funicular segment continuouswith club
AlcidodesMARSHALL,1939,newplacement
8(5) Metasternum flatorbulged,notprojectedtowardscoxa.
9(22) Metasternumbetweenmeso-andmetacoxaemuchlongerthanmesocoxa;fifth
tarsalsegmentprojectingmorethanhalfitslengthoutofthirdsegment in
general;bodymoreorlessparallel-sided.
10(21) Seventh funicular segment narrower than first of club and m ore or less
separated from club MerusGISTEL,
1857(=Mecyso1obusREITTER,1905;Mecys1obusREITTER, l913)___.11
11(12) Procoxaecontiguous;metasternumbulged;pronotumpunctulate
Mcrus (Kismecys1obusVoss, 1956)
12(11) Procoxaeseparated
13(16) Metasternumplanetowardseachhindcoxa,pronotumgranulate;prosternum
betweenprocoxaemostlynarrower thanmesosterna1process.
14(15) Toothofforefemorafinelyserrateonexteriorside__..Merus(Meruss.str ).
l5(14) Toothof fore femora with twoadditional small teeth onexterior sideat base
Merus (ExalcidodesVoss, 1956)
16(13) Contourofmetasternumevenlyarcuateventrallyinlateralaspect;prosternum
betweenprocoxaemorethanhalfthewidthofmesosterna1process.
l7(20) Pronotumpunctateat least inmedianarea; elytrawith intervalswider than
striaeat least on firstto fourth intervals;bodyoftenmetallic.
18(l9) Pronotumwithscattered finepunctures;elytrawithrowof finepuncturesin
striae Merus (MetalialcldesHELLER,1918)
19(18) Pronotumwithdensepunctures;elytrawithshallowlygroovednarrowstriae
Merus (0rnatalcidesHELLER, 1917),newplacement.
20(17) Pronotumgranulate;elytrawithdeepstriae
Merus (GranosalcidesHELLER, 1918),newplacement
21(10) Seventh funicularsegmentalmostaswideasfirstofclubandcontinuouswith
club; metasternum flat; prosternum between procoxaealmost aswideas
mesosterna1process;elytracylindrical,notbroaderthanprothorax;rostrum
oftenwithaprominenceon stmentum in male
pc
CylindralcidesHELLER,1918
22(9) Metasternumbetweenmeso-andmetacoxaeaboutaslongasmesocoxa,more
or lessbulged
NotesontheTribeMecyso1obini 229
23(26) Seventh funicularsegment narrower than firstsegmentofclubandseparate
fromclub Neomecys1obusPAJNIetDHIR,1987__..24
24(25) Mesosterna1processaboutaslongaswide; femoramoreor lessclavate;body
cylindrical;elytrawithscalymarkings
Neomecys1obus(Neomecys1obuss.str.)
25(24) Mesosterna1processshort and very wide, about as great as the lengthof
metasternumbetweenmeso-andmetacoxae, almost aswideaspresternal
process;femoraalmostofthesamewidththroughout;bodyelliptical;elytra
withoutscalydefinitemarkings
Neomecys1obus (Nipponomerussubg nov.)
26(23) Seventh funicular segment almost as wide as first segment of club and
continuous with club SternuchopsisHELLER, 1918__..27
27(28) Subapicaltoothof foretibiaeconspicuous,sharptriangular;procoxaelyingin
themiddleof prosternumbetweensubmarginal sulcusandbasal margin;
bodyelliptic__Sternuchopsls(MesalcidodesVoss,1958),newplacement.
28(27) Subapicaltoothofforetibiaesmallandobtusetriangular ifpresent;procoxae
lyingbehindthemiddleofposternum;bodyoblong____..Sternuchopsis
(Sternuchopsiss.str )=PseudmesalcidodesPAJNI et DHIR, 1987,syn n ov.
Nipponomerussubg nov
Systematicpositiori:AsubgenusofthegenusNeomecys1obusPAJNIetDHIR,1987,
inthetribeMecyso1obini.
Type-species:Neomecys1obus(Nipponomerus)masatakaisp nov.
Etymology. Nippono(Nippon)十merus(nameoftherelatedgenus).
Bodyelliptic,withoutdefinitescalymarking;elytrabico1orous,brownishwithdark
bands; antennaewith firstsegment of funicle thelongest,second longer thanwide,
seventhlarge,aboutaslongaswide,dilatedapically,setosealikeclub,clubmorebulged
thanseventhandweaklyseparablefromitinoutline;pronotumgranulate; forefemora
weaklyorhardlydilatedapically,withtoothobliquelytruncateatapex,withthreesmall
denticlesonexteriorside;tarsiwithsecondsegmenttransverse,clawsegmentprojected
shortlyfromthird;clawssmall,with inner toothverysmaller obsolete; prosternum
betweenprocoxaeverywide,almostaswideasmesosterna1process,procoxaelyingin
themiddlebetweensubmarginalsulcusandhindmargin,prosternumdeeplyemarginate
atanteriormargin,submarginal transversesulcusU-shapedandreachingbasallyat the
bottomas far asor alittlebeyond thelevelbetweenanterior marginsofprocoxae;
mesosterna1processbetweenmesocoxaeverywide;metasternumweaklybulgedbefore
metacoxae,aslongbetweenmeso-andmetacoxaeasmesocoxa,andalmostasgreatas
thewidthofmesosterna1process.
Thissubgenuscomprisesthefollowingtwospecies:
1(2) Clawssimple,connateatbase,inner teethcompletely obliterated;scutellum
minute,shortlinear,enclosedanteriorlybysuture;elytrawitharowoflarge
230 Katsura MoRIMoToand Hiroaki KoJIMA
punctures instriae, the lattera littlewider than intervals; fore tibiaenot
expanded internally; bodylength:3.5-4.2mm___.N masatakaisp
nov.
2(1) Clawsbifidasintheotherspeciesof thistribe,innerteethsmallbutevident;
scutellumsmall,semicircular,openanteriorly;elytrawithintervalswider
thanstriae;foretibiaeweaklyexpandedinternallyatbasalthird;bodylengh:
5.3-6.4mm N nlgrofa(sclatus(KONo,1928),combnov
Neomecys1obus (Nipponomerus)masatakaisp
n ov
(Figs.1-8,16-l9)
M aIe. Bodyelliptic;head,rostrum,antennaeandpronotumblack,legsblackish
to dark brownish, tarsi black, undersideof thoraxblackish, venter brownish black;
elytrabico1ored,basalandmedianbandsbetweenninthintervalsblackishtoinfuscate,
thesebandsdilatedinternallyandcontiguousonfirstandsecondintervals,ormedian
bandoftenobscureorcontinuouslyinfuscatefrombase;scalymarkingabsent,anterior
marginofprothoraxclothedonlywithplumosegrayishscalesfromsidesofpronotum
behindapicalmargintoprosternum, theotherareasparselywithgrayishfinesetae.
Head rugose, foreheadbetweeneyes narrower than rostrum, weakly depressed;
rostrumslightlycurved,muchshorter thanpronotum,subcylindrica1, alittlewider
towardsapex,denselypunctatebehindantennal insertionsinirregular threerows,the
punctures denser towardsbase on eachside, withsmallpunctures beforeantennal
insertions;antennaeinsertedatmiddle, relativelength(width) ofsegmentsfromscape
as76(9.5):18(8) :11(6):7(6):6(6.2):6(7):7(7):10(13,6.5atbase):club26(16);
firstsegmentofclubmuchgreater thanseventhoffunicle.
Pronotum 1.3-1.5 times as wide as long, widest behind the middle, scarcely
narrowedthenceposteriorly,evenlyroundedtowardssubapicalconstriction,truncateat
apex,ocular lobesmoderate;dorsumwithgranulesofequalsizebehindthesubapical
constriction,sparselywithlargepuncturesinsubapical constriction,withsmallpunc-
turesat apicalmargin. Scutellumverysmall,short linear,about as longasthemost
basalpunctureoffirststria,enclosedbysutureatbase.
Elytraslightlywider thanpronotum (20:17-18),about15timesaslongaswide,
parallel-sidedonbasalhalf, thengraduallynarrowingtoapex,striaewithlargeovate
punctures, which become smaller and weaker on declivity, intervals narrower than
striae, rugu1ose.
Legs rather robust, fore femoraslightly dilatedapically from base, with tooth
obliquelytruncateatapex,withthreedenticlesonexteriormargin;hindfemorahardly
reachingfourthventrite;tibiaerobust,notenlargedinternallyinthemiddle;tarsirather
robust,secondsegment13timesaswideaslong, thirdsegment transverseelliptic,1.2
timesaswideaslong,notched to themiddle; clawssimple,connateat base.
Prosternumbroadlyemarginateatapex,fringedwithbranchedsetae;submarginal
transversesulcus definite, its bottom reaching posteriorly a little beyond the level
betweentheanteriormarginsofprocoxae;prosternumbetweenprocoxae0.8timesas
NotesontheTribeMecyso1obini 231
Figs.1-8. Neomecys1obus (Nippo1tomerussubg. nov) masatakai sp. nov. - 1, Underside; 2,
antenna;3,clawsof foreleg;4, foretarsus;5, foreleg;6, tegmenandparameres;7,8,aedeagus,
dorsalandlateralaspects.
wideasprocoxae,almostaswideasmesosterna1process;procoxaelyinginthemiddle
ofprosternumbetweensubmarginalsulcusandposteriormargin;mesosterna1process
transverse, short, declivitous, as wide as distance between meso- and metacoxae;
metasternumweaklybulgedbetweenmeso-andmetacoxaeandverynarrowlyperpen-
dicular at transverse sulcus beforemetacoxa. Venterwithdensepunctures;median
lengthofventritesinproportionfrombaseaste:5:4:4:5,firstventritebehindcoxa
6, allsuturesdefinite.
Maleaedeagusparallel-sidedandevenlyroundedatapex,withsetaebehindapical
margin, tegmen ringed,parameresratherlong,contiguousinternallyatbase.
Fema1e. Similar to maleexcept rostrum as longaspronotum, with faintly
weakerpuncturesbeforeantennal insertionsand first ventritenot longitudinallyde-
pressed in themiddle.
Length:3.5-4.2mm(excludingrostrum).
Holotype: (Type No 3239, Kyushu Univ ), Mt. Bannadake, Ishigaki-jima,
Ryukyus,20-IV-1992, H. KoJIMAleg.
Paratypes: l , Kubura-Hikawa, Yonaguni-jima, Ryukyus, 21~22-IV-1993, H
KoJIMA leg;1早,Mt. 0motodake, Ishigaki-jima,Ryukyus,19-VI-1977,H. IRIEleg;
232 KatsuraMORIMOT0and Hiroaki KoJIMA
l ,Hatsuno,Amami-0shima,13-VI-1962,M.SAT01eg.
Distribution. Japan(Amami-0shima,Ishigaki-jimaandYonaguni-jimaIsis.inthe
Ryukyus)
Notes. Thepresentnewspeciesischaracteristicinhavingthesimpleclawswith
Connatebase,broadintercoxa1processesbetweenpro-andmesocoxae,andshort linear
Scutellum. TheformercharacterwasfirstconfirmedbyMARSHALL(1918)on“Alcides”
deltaandephippiausandthepresentspeciesisthethirdoneintheMecyso1obini. Color
patternof theelytraisvariable,blackishbandsareconspicuousonaspecimenfrom
Amami-0shima,butareobscureintheotherspecimens.
Merus(Merus)unlfaisciatussp
nov
(Figs9-15,20,21)
Male and female. Derm black, antennal clubs, foretibiaeexceptingbase
andpart of tarsioftenreddishbrown,generallyclothedwithsparseshort appressed
setae;prothoraxwithfivenarrowstripesofgrayishfulvousscales,medianstripenarrow,
ofthesamewidththroughout,dorsolateralstripesoblique,weaklydilatedtowardshind
an9lesofpronotum, lateralstripesonpleuraoften ill-defined;elytrawith following
markingsofthesamescalycoloration:aroundspotonintervals5and6atone-third
frombase,weaklyobliquetransversebandfrominterval9atone-thirdfromapextotop
ofdeclivity,whichisslightlynarrowerthanmedianstripeofpronotumandinterrupted
bystria1,ashortstripeoninterval3ondeclivity,beingnarrowlydistantfromapexand
widely so from thescaly band; underside with fulvous scales, which are dense on
Prosternum before coxae, anterior and posterior cornersof metepisterna, and side
marginsofventrites.
Headwithpuncturesdensebetweeneyesandbecomingfinerposteriorly; forehead
betweeneyeswithdensescales. Rostruminmalelongandslender,1.1-12tjmesthe
lengthofpronotum,scarcelydilatedapically,closelypunctateaboveantennalscrobein
lateralaspect,andmorefinelysoondorsumofapicalhalfinthemedianpartandapex;
antennal insertionatathirdfromapex;rostruminfemalelonger,1.8-1.9timesaslong
asPronotum,antennalinsertionatalittlebeyondthemiddle. Antennal funiclewithfirst
segmentclavate,relativelength(width)fromscapetoclubasl58(20):33(14):32(11):
12(12):12(12):12(12):14(13):22(21):55(24), seventhsegment dilated apically
andseparatedfromclubbyweakdifferenceofoutline,pubescentalikeclub.
Prothorax transverse (20:17), widest just before thebase, with sides gently
rounded,shallowlyconstrictednearapex,dorsalapicalmargintruncate,ocular lobes
moderate; dorsumweaklyconvexlongitudinally,withshinygranulesof unequalsize
excepting apical area beyondsubapical constriction. Scutellumnot enclosed, small,
oval,shiny.
Elytra wider than pronotum, elongate, 7/4 times as long as wide, widest at
Shouldersandverygraduallynarrowingposteriorly,suturalareanot attened atbase;
Striaewithratherlargedeeppunctures,manyoftheseptabetweenthembeingsomewhat
Noteson theTribeMecysolobini 233
V
v
P I v
f P -
4
-VA
13
Figs 9-15. Merus (Merus) unifaisciatussp nov. - 9,Clawsof foreleg;10, foretarsus; ll, fore
leg;12,hindleg;13,antenna;14,15,aedeagus,dorsalandlateralaspects
raisedandunitinglaterallywithadjoiningintervals,whichformirregularandrugose
surface between striae 1 and 5, lateralstriaeoutside the 6rather regular; intervals
between1and4ashighasseptaofstriae,thoseof5to9convex,regular. Legsslender,
hindfemoraalmost reachingthecaudalmarginofventrite5;all femorawithasharp
tooth, its outer slope slightly convex and finely crenulate; front tibiae with faint
subapical prominence and setal tufts, but no tooth, bisinuate on inner edge, with
roundedweaksubmedianexpansion;tarsiwithsegment2longer thanwide,segment3
almostaslongaswide,widestatapicalthird,notchedtoathirdfrombase,clawsegment
ratherslender,exposedmorethanhalf fromthenotch.
Relativewidthof intercoxa1distanceofprosternum:mesosternum:metasternum
as l:3:5. Venterwithfirstventritebehindcoxahardlylonger thansecond,thelatter
slightlylonger thanthird,whichisaslongasfourth;firstventriteweaklydepressedin
male.
Maleaedeagusslightly narrowing frombasetonear ostium,stronglynarrowed
thenceapicallywithroundedmarginsandstronglyprolongedapicallyasveryslender
process; internalsacwithconicalspinulesonwholesurfaceexceptinginnermostpart,
thespinulesminuteondorsalsidenearostium,largeatsides,moderateontherest.
234 KatsuraMoRIMoToand Hiroaki KoJIMA
16 17
18 19 21
Figs.16-19. HabitusphotographsofNeomecys1obusandMerusspp. - 16-19. N (Nipponomerus
subgnov)masatakaispnov. (16,paratypefromYonaguni-jima;17,holotype;18,19,paratype
fromAmami-0shima, rostrumdistortedatbase);20,21,M. (Merus)unifaisclatussp nov. (20,
female;21,male).
Length:5.5-7.0mm(excl rostrum).
Holotype:早(TypeNo3240,KyushuUniv),Mt.0moto,Ishigaki-jimaIs.,Japan,
2-V-1976,T. TAKAHAsHI leg.
Paratypes:Awa,OkinawaIs.,2早,15-V-1971,K.MIYAGIleg. Mt.Katuu,Nago,
Ishigaki-jima,6f,4早,15-VII-2006,H.HIRAN01eg.Ishigaki-jima,l f,2早,15-V-1936,
,. MASAKIleg. Fenchihu,ChiYaiHsien,Taiwan,11(1',1 ・ 7-VII-1965 T NAKANEleg
2 12-IV-1965, T.SHIROzUleg; lei1',11-IV-1965,S. MIYAMoT01eg. Nanshanchi,
,
WenchuanHsien,Taiwan,1早,27-IV~4-V-l972,T.MIKAGEleg.
Distribution. Japan (Ryukyus:Okinawa-hontoandIshigaki-jimaIsis),Taiwan.
Etymo1og;y. Nameofthisnewspeciesistaken fromthepatternofthescalyband
Noteson theTribeMecyso1obini 235
onelytra.
Hostplant. Mr. HIRANoconfirmedtheoviposition into thestemofStrobilanthes
tashiroiHAYATA(Okinawa-suzumushisoinJapanese) (Acanthaceae)and foundlarvae
inside thestem.
Notes. ThisnewspeciesbelongstothesubgenusMerus(=Mecyso1obus) inhaving
thefollowingfeatures:Bodyoblong;pronotumgranulate;clawsegmentoftarsislender,
exposingmorethanhalfthelength fromthedeepnotchofsegment3;antennaewith
funicle7pubescentalikeclub,almostaswideaslong,separatedfromclubbytheweak
differenceof outline; intercoxa1distance of prosternum much narrower than that of
mesosternum, procoxae lyingbehind themiddle; intercoxa1distance of metasternum
slightlywider thanthatofmesosternum,metasternumplanetowardseachhindcoxa;
prothorax with threeor fivescalystripes,elytrawith one or two linear bands, the
anterior oneobliqueor reduced toaspot,posterior oneobliqueor weaklyso. The
present new species constitutes the decursus species-group including M. decursus
PAscoE,meuitusFAUST,morosusHAAFpseudome11itusHELLERand、1enuStuSHAAFin
havingabandbehindthemiddleandaspotonintervals5and6atone-thirdfrombase
onelytra,andtheextraordinaryslenderprocessattheapexofaedeagusmaybeanother
characteristicofthisgroup. Thepresentnewspeciesiseasilyrecognizedfromthemby
thefollowingpoints:pronotumwithfivestripes;elytrawithposteriorbandslightlywider
thanmedianandaswideasdorsolateralstripesofpronotum,narrowly interruptedby
suture; foreheadbetweeneyeswithdensegrayishscalescompletelyconcealingfovea;
rostrumcylindrical,withoutdenticlesontheundersidebehindapex,withoutanytrace
ofsulcior depressionsonsides; aedeagusweaklybent ventrallyat veryslenderand
extraordinary longapicalprocess.
TwospecimensbeforeusfromThailand(DoiSuthepandChiangMal)arevery
sjmjlar tothepresentnewspecies,buttheforeheadissparselyclothedwithsofinesetae
thatthefoveaandpuncturesarefreelyvisible,andthesubmedianexpansionofthefore
tibia is weaker.
A ListofMecysolobini inJapan
1. Merus(Merus)?avoslgnatus(RoELoFs,1875) [Alcldes]
2. Merus(Merus)unita(sciatusMoRIMOToet KOJIMA,2007
3. Merus(Merus)erro (PAscoE,1871) [Alcides]
4. Merus(Merus)nipponicus(KoN0,1930) [Alcides]
5. Merus(Merus)piceus(RoELoFs,1875)?.Alcides]
6. Cylindralcidestakahashii (KoN0,1930),comb nov. [Alcldes]
7. Sternuchopsis(Sternuchopsls)waltoni (BoHEMAN,1844) [Alcides] [=albolineatuS
RoELoFs,1875, thisrecordfromJapanisdoubtful]
8. Sternuchopsis(Mesalcldodes)trifidus(PAscoE,1870),comb nov. [ACI ldeS]
9. Neomecys1obus(Nipponomerus)masatakaiMoRIMoToetKOJIMA,2007
10. Neomecys1obus(Nipponomerus)nigrofatsciatus(KoN0,1928),comb nov. [AICideS]