Description of Oromurcia magadanensis sp. nov. (Acari, Oribatida, Ceratozetidae) from Russia, with remarks on biogeography of the genus Oromurcia Thor, 1930.

Species of the genus Oromurcia Thor, 1930 (Oribatida, Ceratozetidae) mainly have an arctic or alpine distribution in the Western Palaearctic region and Greenland. We describe a new species of Oromurcia from Northeast Asia (Magadan Region, Russia) based on adult and juvenile instars. Numerous populations of Oromurcia magadanensis sp.

Distribution, habitats, and redescription of the rare mite species emIphidonopsis/em emsculptus/em Gwiazdowicz, 2004 (Mesostigmata: Ascidae).

Iphidonopsis sculptus Gwiazdowicz, 2004, is currently known only from the type locality in eastern Poland and a record in southwestern Finland (Huhta, 2016). Here, we record this species from twelve localities elsewhere (Europe, Siberia, Far East of Russia, Canada) indicating its broadly Holarctic geographical range. Another genus member, Iphidonopsis magnanalis (Ma Yin, 1999), is known only from China.

Morphological development, distribution and ecology of the arctic oribatid mite Hermannia scabra (Acari: Oribatida: Hermanniidae) and synonymy of Hermannia gigantea.

The topotypes (adult and juvenile instars) of the arctic oribatid mite Hermannia scabra (L. Koch, 1879) (Oribatida, Hermanniidae) from Vaygach Island (easternmost arctic Europe) were investigated and compared with those of Hermannia gigantea Sitnikova, 1975 collected from southwest Taymyr Peninsula, northern Middle Siberia, resulting in the following new taxonomic proposal: Hermannia scabra (L. Koch, 1879) (= Hermannia gigantea Sitnikova, 1975, syn.

North Pacific versus North Atlantic: a case with species of the amphiboreal littoral mite genus Thalassogamasus gen. nov. (Parasitifomes, Mesostigmata, Parasitidae).

A new amphiboreal gamasid mite genus, Thalassogamasus gen. n. is described, characterised by two distinct dorsal shields (opisthonotum hypotrichous, usually with ten pairs of setae); peritrematal shield reduced and posteriorly free; setae al1, al2 on palp genu and al on palp femur entire; dorsal chaetome homogenous; opisthosoma laterocaudally hypertrichous; in female, epigynium whip-like anteriorly, endogynium with two thick sclerotic masss; in male, tritosternum fully lost, hypostome deeply cleft, cheliceral arthrodial membrane fringelike.

A new species of Arctoseius Thor, 1930 (Acari: Ascidae) from taiga regions of the Palaearctic, with a key to Arctoseius species of Fennoscandia, NW Europe.

A new mesostigmatid mite species belonging to the genus Arctoseius Thor, 1930, is described based on material from subarctic coniferous forests, Finland, and Altai highlands, Russia. Arctoseius ambiguus sp. nov.

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.

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.