| abstract | This paper reports on six species of the genus Cosmolaelaps (Laelapidae) in Russia: Cosmolaelaps lutegiensis (Shcherbak) collected from soil-litter, C. chianensis (Gu) and C. rectangularis Sheals, 1962 from Myrmica sp. (Formicidae), and Cosmolaelaps lasiophilus Joharchi sp. nov., Cosmolaelaps latisetis Joharchi sp. nov., and Cosmolaelaps sejongi Keum et al. from Lasius spp. (Formicidae). Two new species are described and illustrated from adult females and supplementary descriptions of three other species are presented to facilitate species delimitation. In addition, an identification key to all known Russian species of the genus is presented. |