Two new species of Neurigona Rondani, 1856 (Diptera: Dolichopodidae) from Sakhalin, Russia, with a key to species from the Palaearctic Far East

Neurigona polevoii Grichanov sp. nov. and Neurigona humalai sp. nov. from the southern part of the Sakhalin Island in the Russian Far East are described and illustrated and associated with the Neurigona pallida species group. A key to twenty five Neurigona Rondani species known from the Palaearctic Far East is provided. The World fauna of the genus contains now 170 species and the Palaearctic fauna has increased to 44 species. In all, 77 long-legged flies are known from the Island of Sakhalin.