Dolgin M.M., Kostyukov V.V.
Tetrastichus chakassicus sp. n in described. It is solitary ectoparasite of larvae of larch bud midges (Dasyneura rozhkovi Mamaev et Nokolskiy), Siberian larch pest of great concern. The new species differ from T. avetjanae Kostjukov by a wider head, longer buccal stitching, lesser number of bristles along the internal side of every parapsidal groove, by ashorter part of the ovipositor seen from under the last abdominal tergite. Some specific features of biology and phenology of parasite are reported