Key words: Myobiidae, Radfordia cricetuliphila sp. n., Cricetidae.
A new myobiid mite species Radfordia (Microtimyobia) cricetuliphila sp. n. (Acari: Myobiidae) from the striped hamster Cricetulus barabensis (Rodentia: Cricetidae) from Buryatia is described. The new species is closely related to R. (M.) triton Fain et Lukoschus, 1977 ex Tscherskia triton (Cricetidae). These two species are distinguished by characters as follows.
R. (M.) cricetuliphila sp. n. Female: the setae sci, see and l1 are 70-81, 63-67 and 51-60 long in 3 specimens respectively; male: the setae cxI 1-2 are lanceolate, 4 in width, the setae ra are hair-like, the setae sci 38-40 long in 3 specimens.
R. (M.) triton. Female: the setae sci, see and l1 are 134, 90 and 78 long respectively; male: the setae cxI 1-2 are hair-like, the setae ra are membranous, the setae sci 80 long.
The new species group triton including 3 species - R. (M.) triton, R. (M.) abramovi Bochkov et Mironov, 1998 ex Phodopus spp. and R. (M.) cricetuliphila - is established within the subgenus Microtimyobia. All species of this group are ectoparasites of hamsters (Cricetinae). In females of this group the setae cxII 1 are short, the setae d3, d4 are lanceolate; in males, the setae cxII 1 are short, the genital shield with long apex. The species R. (M.) triton and R. (M.) cricetuliphila are closely related and represent typical species of the group, while R. (M.) abramovi differs well from both these species. The host genera (Tsherskia and Cricetulus) of these two myobiid species are also more phylogenetically related than either to the genus Phodopus.
The fourth Radfordia species known from hamsters, R. (M.) cricetulus Fain, 1973 (the parasite of Cricetulus migratorius), is quite similar by the structure of male genital shield to Radfordia species commonly associated with voles (Arvicolinae). It is possible to suggest that R. (M.) cricetulus or its ancestor had an origin on voles and then migrated on hosts of the genus Cricetulus, namely on C. migratorius.