Assessment of Epizootiological Value of Fleas (Insecta, Siphonaptera) in the Phenomenon of Seasonal Plague Manifestations in the Steppe Natural Plague Foci of Souslik Type in the Northern, North-Western Pre-Caspian and Pre-Caucasus Regions
It has been determined that timescales of the beginning of summer intensive epizootics in the plain natural plague foci of souslik type in the Northern, North-Western Pre-Caspian and Pre-Caucasus Regions coincide with the period of adult small sousliks migration to the landscape lowering, building of protective burrows, and formation of flea micro-populations in them. Substantiated is existence of the mechanism that determines seasonal character of animals infecting during 30-40 days (III decade of May - II decade of June) at the same sites of focal territory. This mechanism is not connected with absolute indices of flea abundance in the hair and burrows of animals. The phenomenon of seasonality and micro-focality of plague manifestations is demonstrated to be associated primarily with plague microbe transfer in the organism of fleas at different stages of their metamorphosis, by the representatives of soil biota (parasitic nematodes and protozoa), at the sites with edaphic factors (humidity, availability of organic substances, etc.) most favorable for preservation and maintenance of plague agent.