Abstract
The distribution of Hexatoma (Eriocera) ussuriensis Alexander is analyzed on the basis of the authors' original material and the specimens kept in the collection of the Zoological Institute, St. Petersburg (including the types). Diagnostic characters of H. ussuriensis are summarized. H. ussuriensis is recorded for the first time from Mongolia, Japan and eastern Siberia (including new records from five provinces of Russia: Kemerovo Province, Republic of Altai, Krasnoyarsk Territory, Irkutsk Province, and Buryatia). The known distribution of this species is wide; it ranges from ca. 61° to 43°N, from 30 to 650 m above the sea level, and covers different landscape-climatic zones (from boreal forest to dry steppe). Records of H. ussuriensis are confined mostly or entirely to different-type running waters, which probably serve as larval habitats. They are briefly characterized and illustrated. Adults of H. ussuriensis were for the first time reared from larvae collected in the Chikoi River (Buryatia, Russia).