A new species of Symbiocladius Kieffer, 1925 (Diptera: Chironomidae: Orthocladiinae) from the Eastern Palaearctic

The adult male, pupa, and fourth instar larva of Symbiocladius (s. s.) villosus Makarchenko et Makarchenko, sp. n. from the Russian Far East and Japan are described and figured. Adult male of a new species separated from all known species of subgenus by presence of a pair rodshaped chitinized structures which situated above apical parts of phallapodemes, and is closely related to the Palaearctic species S. (s. s.) rhithrogenae and the Nearctic S. (s. s.) chattahoocheensis. S. (s. s.) villosus sp. n. can be distinguished from the first species by shape of gonostylus which expands from the base to the middle and with longer and more numerous setae. From S. (s. s.) chattahoocheensis a new species can be separated by roundish-triangular dorsal part of inferior volsellae and presence of 2 megasetae on gonostylus.