The Eumeninae (Hymenoptera, Vespidae) of Hong Kong (China), with description of two new species, two new synonymies and a key to the known taxa

A total of 38 species belonging to 26 genera of Eumeninae are recorded from Hong Kong, among which two new species, namely Allorhynchium radiatum sp. nov. and Orientalicesa nigra sp. nov. are described and illustrated. Symmorphus tsushimanus Yamane, 1990 is newly recorded from China and its female is firstly described. Eighteen species are newly recorded for Hong Kong. Antepipona ferruginea Kim & Yamane, 2003 is synonymized with Antepipona rufescens (Smith, 1857) ( syn. nov. ) and Eumenes quadratus obsoletus Dover, 1926 is synonymised with Eumenes quadratus quadratus Smith, 1852 ( syn. nov. ). A checklist, a key and illustrations to Hong Kong Eumeninae are also provided.