Symbiotic host of Triartiger reductus Nomura (Coleoptera, Staphylinidae, Pselaphinae, Clavigeritae) in the Island of Tsushima, Japan

2008·1.3 MB·

by  Komatsu, Takashi

Elyt,a,Tokyo,36(1):227-228,May30,2008
Symbiotic Host ofTriartiger reductus NoMURA
(Coleoptera,Staphylinidae, Pselaphinae,Clavigeritae)
in the Islandof Tsushima, Japan
Takashi KoMATsUI) andMunetoshi MARUYAMA2)
1) DepartmentofBiology,FacultyofScience,ShinshuUniversity,Asahi3-1-1,
Matsumoto,Nagano,390-8621Japan
2)TheKyushuUniversityMuseum,Hakozaki6-10-1,Fukuoka,812-8581Japan
TheclavigerinebeetleTriartiger redtlctiisNoMURA, 1997(Fig. 1)wasrecorded from the
Islandsof Tsushima, westernJapan, and only a few specimens have hitherto been collected
(NoMURA,1997).Thoughitwaspresumedtobeamyrmecophileasmostspeciesofthesupertribe
Clavigeritae, no information on antassociation of thisspecieswasavailable. Recently, T. K.
visitedTsushimafor investigationofmyrmecophi1ousinsectsandfoundnumerousspecimensof
this rarespecies. Thebeetleswerecollectedfromthe nestsofCrematogasterosakensis FOREL,
1900 (Myrmicinae). Sixteen colonies of C. osakensls were investigated, seven of thembeing
parasitizedbyT reductus. DuringhisfourdaysofinvestigationinTsushima,T. K.investigated
atotalof17speciesofants(totally91colonies),butbeetleswerefoundonlyinthenestsofC
osakensls. Therefore,C osakenslsismostprobablythehostantof T reductus. Normallythreeor
Fig.1. Aliving 「ria・lt1ge・l ・,ec11lctl1s,dorsalview
228 Takashi KoMATsUand Munetoshi MARUYAMA
Fig.2. TriartlgerreductusinanestCrematogasterosakensis
fourbeetleswerefoundpercolony,thoughsometimesmorethantenbeetleswerefoundinasingle
antcolony(Fig 2).WhenT. K.inspectedanunderstonecolony,thebeetleswalkedslowlyinthe
trailofantsandescapedintotheholecontinuingunderground.Theantsshowedclearinterestin
thebeetlesandtappedtheirbackswiththeirantennaeforashort time.Behaviour thatantcarries
thebeetlewithitsmandibleshasnotbeenobservedinthesymbioticassociationofCosakenslsand
T reductus, thoughthisbehaviouriscommonlyobservedinassociationsbetweenbeetlesof the
genus Diartiger SHARP, 1883, a close relative of Triartiger, and ants of the genus Laslus
FABRICIUS,1804 (Formicinae) (MARUYAMA,pers.obs)
Triartiger reductusNoMURA,1997
Speclmerlsex:1amined 27exs.,Sasunaotsu,Kamiagata-machi,Tsushima-shi,Nagasaki,Japan,
27-IV-2008, T. KoMATsUleg;5exs.,samedatabut, 29-IV-2008. In thecollectionsof the
KyushuUniversityMuseumandtheNationalMuseumofNatureandScience,Tokyo.
Symbiotichost.Crematogasterosakensis.
Reference
NoMURA, S., 1997. A revision of the clavigerinegenus T1・iartiger KuBoTA (Coleoptera, Staphylinidae
Pselaphinae) fromTaiwanandJapan.Elytra,Tokyo、25:435-444.