Abstract: | Records of myobiid mites parasitizing rodents of the former USSR are summarized. Totally, 46 myobiid species belonging to 4 genera were recorded in the fauna of the former USSR: Austromyobia (2 species), Cryptomyobia (10 species), Myobia (7 species), and Radfordia with the 3 subgenera, Radfordia s.str. (4 species), Graphiurobia (6 species), and Microtimyobia (17 species). Seventy one rodent species were recorded as hosts of myobiids. More than 60% of potential myobiid hosts occurring in the fauna of the former USSR were examined. Keys to all recorded genera, subgenera, and species (males, females, and tritonymphs of most subgenera) are provided and supplied by figures where it is necessary. The emended diagnoses of all recorded mite genera and subgenera are provided. One species, Radfordia (Graphiurobia) selevinia sp. nov. from Selevinia betpakdalensis (Gliridae) is described as a new for science. The host-parasite relationships of myobiids and rodents of the former USSR are briefly discussed. In the examined region, myobiids are absent on representatives of the suborders Castorimorpha and Hystricomorpha. Among Sciuromorpha, myobiids (subgenus Graphiurobia) are recorded only on representatives of the family Gliridae. The suborder Myomorpha harbors myobiids of the 3 genera: Cryptomyobia – parasites of Dipodidae, excluding Sicistinae); Austromyobia – parasites of Gerbillinae, Myobia and Radfordia s.str. – parasites of Murinae, Radfrodia (Microtimyobia) – parasites of Cricetidae. Among the superfamily Muroidea, myobiids are absent on representatives of the families Calomyscidae and Spalacidae. Finally,\n myobiids have, probably, been extinct on some cricetids having the subterranean mode of life, such as Ellobius spp. and Prometheomys schaposchnikovi. Their absence on species of the genus Lagurus (Cricetidae) is, probably, the result of the “missing of the boat”. |