title: Two new species of Syrphidae (Diptera) from Chukotka (Northern Russian Far East).
abstract: Two new species, Platycheirus beringiensis sp. n. and Cheilosia chukotana sp. n., are described from Chukotka (northern part of Russian Far East). The new Platycheirus is close to Platycheirus immarginatus (Zetterstedt), but differing by the following characters: fore tibia with a black stripe on posterior side; mid-femur without fine black curved hairs directed to the base of the femur; mid-tibia without long anteroventral hairs; abdomen black with fine brownish lustre on tergites. The new Cheilosia species is close to Ch. semifasciata Becker, but differs by its characteristic sharply raised central knob, and by lack of transversal stripe and indentation in anterior third of frons.
authors.affiliation: Laboratory of Systematics of Invertebrate Animals, Institute of Systematics and Ecology of Animals, Russian Academy of Sciences, Siberian Branch, 11 Frunze Street, Novosibirsk 630091, Russia.; Email: bark@eco.nsc.ru.
authors.forename: Anatolij V
authors.initials: AV
authors.lastname: Barkalov
authors.affiliation: Amur State University of Humanities and Pedagogy, 17/2 Kirova Street, Komsomolsk-na-Amure 68100, Russia.; Email: valerimutin@mail.ru.
authors.forename: Valerij A
authors.initials: VA
authors.lastname: Mutin
mesh_terms: D000818:Animals; D004175:Diptera / Q000033:anatomy & histology / Q000145:classification*; D017753:Ecosystem; D005260:Female; D008297:Male; D012800:Siberia