[Distribution and biological characteristics of Ixodes persulcatus (Ixodidae) ticks in the health resort zone of Leningrad].

The occurrence of an isolated population of I. persulcatus in the health resort zone of Leningrad is due to a character of vegetation, soils, relief and availability of such food sources as birds, hares and elks. The seasonal dynamics of ticks abundance depends very little on temperature but depends on the amount of precipitations and on the number of days with precipitations; long fluctuations in the ticks abundance are stimulated, in general, by temperature. Annual mechanical collections of ticks in nature and their chemical extermination on a small area do not affect sufficiently the abundance of populations.