Revision of the fungivorous genus Oxyporus ( s. str. ) (Coleoptera: Staphylinidae: Oxyporinae) of Japan, with preliminary analysis of host relationships, species richness and zoogeography

The Japanese members of the genus Oxyporus (s. str.) are revised. Eleven species are recognised as follows: O. rufus (Linnaeus, 1758) [O. tosensis Takeuchi, 1941, n. syn.; O. rufus osawai Nakane (2) 10 species are sympatrically distributed in Honshu and Shikoku, and nine in Kyushu; (3) although species richness in Japan is highest in Far East Asia, only O. imitator is endemic; (4) the region with highest similarity to Japan is calculated to be the Korean Peninsula. A comparison of Oxyporus fauna across the regions of East Asia suggests that it is necessary to conduct further comprehensive taxonomic studies. Additionally, it is hypothesised that multiple Japanese Oxyporus species can occur sympatrically because of the existence of reproductive isolation due to differences in the hosts used. A checklist of the Oxyporinae of the World is provided in the appendix.