Pachyseius anisimovi sp. nov. is described based on specimens from soil and litter in the Altai Mountains and the West and East Sayan Mountains in South Siberia, Russia. A key to ten Pachyseius species known from Asia is provided. 

The family Pachylaelapidae Berlese, 1913 (Acari: Mesostigmata) includes a total of 16 valid and adequately described genera, namely Chaetodellus Mašán & Halliday, 2013, Elaphrolaelaps Berlese, 1910, Mirabulbus Liu & Ma, 2001, Neopachylaelaps Mašán, 2007, Olopachys Berlese, 1910, Onchodellus Berlese, 1904, Pachydellus Mašán, 2007, Pachyglobolaelaps Mašán, new genus, Pachylaelaps Berlese, 1888, P...

Pachylaelaps (Pachylaelaps) pyrenaicus sp. n. and Pachylaelaps (Longipachylaelaps) brevipilis sp. n. (Acari, Pachylaelapidae) are described and illustrated based on specimens from litter and soil detritus of forest habitats in Spain (Pyrenees Mts) and Portugal (Serra da Labruja Mts), respectively. An identification key to European species of the genus Pachylaelaps Berlese, 1888 is provided.

Two new species of the genus Pachyseius are described from leaf litter in Turkey. Pachyseius destitutus sp. nov. is described based on the female, and P. quadrigeminus sp. nov. is described based on the female and male. These species have some uncommon character states for the genus, such as the absence of dorsal shield seta z1, four pairs of setae on the ventri-anal shield, and a male with a h...