The Japanese species of the tribe Platylabini were revised. So far, five genera and 14 species were recorded from Japan. In the present study, 53 species within 16 genera of the tribe were recognized. The following genera were newly recoded from Japan: Apaeleticus Wesmael, 1845, Clypeolabus Heinrich, 1974, Cratolaboides Tereshkin, 2009, Cratolabus Heinrich, 1974, Dentilabus Heinrich, 1974, Ectopius Wesmael, 1859, Heinrichiellus Tereshkin, 2009, Linycus Cameron, 1903, Notoplatylabus Heinrich, 1936, and Poecilostictus Ratzeburg, 1852. The records of Clypeolabus and Cratolabus also represented new records from the Palearctic region of the genera. A new genus and species, Metopilabus robustus gen. et sp. nov. was described and its host, Ditrigona virgo (Butler, 1878) was recorded. The generic definitions of each genus were revised. In this thesis, I treated following generic synonymies: Pristicerops Heinrich, 1961 syn. rev. as junior synonym of Pristiceros Gravenhorst, 1829; Lamprojoppa Cameron, 1901 syn. rev. as junior synonym of Platylabus Wesmael, 1845. The genus Linycus comprises a single species in Japan, and it resembles a Holarctic congener, L. exhortator (Fabricius, 1787) except for the coloration. The genus Hypomecus Wesmael, 1845 also comprises a single species. Japanese specimens were treated as a subspecies of H. quadriannulatus (Gravenhorst, 1829), H. quadriannulatus tylus Uchida, 1936 by Townes et al. (1965). I examined DNA barcodes (partial sequences of mitochondrial COI) and compute p-distances among Linycus and Hypomecus. Japanese specimens of Linycus differed from L. exhortator from Canada and United Kingdom by about 5% p-distances, thus in this study, I treated Japanese species of Linycus as a new species, L. rugosobasalis sp. nov. Japanese specimens of Hypomecus differed from H. quadriannulatus from Canada by about 1.5% p-distances, so I followed the treatment of Townes et al. (1965). Other species which are new to science and new to Japan in present study are as follows: Apaeleticus japonicus sp. nov., Asthenolabus delicatus sp. nov., As. okiensis sp. nov., Clypeolabus brevis sp. nov., Cl. nigrus sp. nov., Cl. matsumotoi sp. nov., Cl. unicolor sp. nov., Cl. watanabei sp. nov., Cyclolabus kyushuensis sp. nov., Cratolaboides palpalis Tereshkin, 2009, Cratolabus yamauchii sp. nov., Dentilabus nigripodus sp. nov., D. iyoensis sp. nov., Ecopius nigricapitis sp. nov., Heinrichiellus kusigematii sp. nov., He. nambui sp. nov., He. japonicus sp. nov., Notoplatylabus podolicus conterranius Tereshkin, 1993, Poecilostictus cothurnatus (Gravenhorst, 1829), Pristiceros ferruginous sp. nov., Pr. gloriosus sp. nov., Pr. kusigematii sp. nov., Pr. tricolor sp. nov., Pr. sp. A, B, E, H. The phylogenetic analyses using COI gene revealed monophyly of Platylabini. The genus Heinrichiellus was not located within Platylabini clade in any analyses. The morphological characteristics also supported the exclusion of Heinrichiellus from Platylabini.
(主査) 教授 大原 昌宏, 教授 秋元 信一, 准教授 吉澤 和徳, 助教 首藤 光太郎
農学院（環境資源学専攻）