Review of the mite subfamily Arctoseiinae Evans with a key to its genera and description of a new genus and species from Siberia (Parasitiformes, Mesostigmata, Ascidae).

We redefine the subfamily Arctoseiinae of the family Ascidae, and describe a new genus, Maxiniagen. n., based on a new species, Maxinia arctomontanasp. n., whose adults display a combination of attri-butes uniquely different from other genera of the subfamily. The geographical range of Maxinia arctomontana is limited by arctic and mountain landscapes of Siberia. This description provides furtherdata on the arctic distribution and morphological diversity of the subfamily Arctoseiinae, which is unusually well represented in that region (26-83% in local gamasid mite faunas). Conceptual problems with the genus Iphidonopsis Gwiazdowicz, 2004 are reviewed, and a new combination, Iphidonopsis magnanalis (Ma & Yin, 1999) comb. n., is presented for Iphidozercon magnanalis Ma & Yin, 1999 from China. The genus Diseius Lindquist & Evans, 1965 is provisionally moved from the family Ascidae to the Digamasellidae. A new key to the genera of Arctoseiinae is presented.