[Little-known parasite of wild birds, Ixodes caledonicus Nuttall, 1910, in the fauna of the USSR (Ixodoidea, Ixodidae)].

Ixodes caledonicus differs from the most allied species I. berlesei at all active phases of its life cycle. In the USSR I. caledonicus is distributed in the Ukraine-in the Crimea, on Tarkhankut and Kerch Peninsulars, in Azerbaijan-in the south-eastern spurs of the Creat Caucasian ridge and in the midcourse of the river Araks, in Tadzhikistan-on the southern slope of the Gissar ridge. The species is reported from Great Britain, Sweden, FRG and Poland. I. caledonicus belongs to a nest-burrow type of parasites, is recorded from mountain and elevated regions, lives in rocks. Birds nesting in rocks serve as its hosts. Differential (as regards I. berlesei) diagnoses of female, nymph and larva are given.