Stenichnus lackneri sp. n. of Japan (Coleoptera, Staphylinidae, Scydmaeninae)

Abstract

Stenichnus Thomson, 1859 is a species-rich and common genus in the western Palaearctic, but only a few species are known from the Far East. Six species have been so far recorded from Japan (Sharp 1886; Jałoszyński 2004, 2006; Jałoszyński, Arai 2009). Interestingly, the Japanese species occur in the temperate or cool climate of Hokkaido in the north-east (Stenichnus minipollens Jałoszyński, 2004) and in subtropical forests of the south-western Yaeyama Archipelago (St. bellulus Jałoszyński, 2004 and St. totoro Jałoszyński, 2004), showing a broader range of ecological plasticity than their western Palaearctic congeners. Two more species are known to occur in the Japan mainland, i.e., St. pollens (Sharp, 1886) in Kyushu and St. sakurayamanus Jałoszyński & Arai, 2009 in the central part of Honshu, and one species, St. mitai Jałoszyński, 2006, was discovered on the small Nakanoshima Island of the Tokara Archipelago. Only the species that occur in the Yaeyama Islands are relatively common, all remaining species are known from holotypes only. Interestingly, St. pollens and St. minipollens, which occur on different islands separated by nearly 1500 km, share very similar aedeagi with a unique long ventral projection (Jałoszyński 2004).