A new species of the gamasid mite genus Arctoseius Thor, 1930 (Parasitiformes, Mesostigmata, Ascidae) from Russia with a key to the multidentatus species-group

A new gamasid mite species belonging to the genus Arctoseius Thor, 1930 is described from Russia. Arctoseius koltschaki sp. n. is distributed in the plain and mountain tundras from Khibiny Mountains to Chukotka on the north and to West Sayan Mountains on the south. A diagnosis and a key for identification of species comprising the multidentatus species-group (A. multidentatus Evans, 1955; Arctoseius wisniewskii Gwiazdowicz & Kamczyc, 2009; A. sexsetus Lindquist & Makarova, 2011; A. haarlovi Lindquist & Makarova, 2011; and A. koltschaki sp. n.) are given.