New taxonomic notes on the genus Coenosia Meigen (Diptera: Muscidae), with the description of four new species from North-East Russia and the Altai Mountains
Four new species of Coenosia Meigen, 1826 are described from the Magadan region, Chukotka Autonomous Okrug and Altai Mounts (Coenosia galina n. sp., C. gorodkovi n. sp., C. koni n. sp., C. adriani n. sp.). Descriptions of the unknown females of C. tschernovi Sorokina, 2014 and C. wrangelensis Sorokina, 2012 are given. Three new synonymies are proposed: Coenosia (Hoplogaster) elegans Huckett, 1965, n. syn. of Hoplogaster baicalensis Schnabl in Becker & Schnabl, 1926; Coenosia tangera Sorokina, 2009 n. syn. of Coenosia (Hoplogaster) conflicta Huckett, 1965; Coenosia carinata Cui & Li, 1996 n. syn. of Hoplogaster morrisoni Malloch, 1924. Images of the new species and the male terminalia are given. The cytochrome oxidase I gene sequences (CO1) of two new species and nine other species are provided and discussed. The distribution of the Coenosia apukaensis species-group is discussed.