Popov Nikolay Vladimirovich RussiaSaratovRussian Research Anti-Plague Institute "Microbe", 46, Universitetskaya Str., Saratov, 410005, Russiaзаведующий лабора- торией эпизоотологического мониторингадоктор биологических наук, профессорpopov47@mail.ru Author's articles 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 Spatial Structure of Spermophilus Pygmaeus Pallas, 1778 Settlements Found in the Territory of the North-Western Caspian-Sea Region Winter months’ temperature rises effect on duration of phenological phases for Spermophilus pygmaeus Pallas, 1778 populations located in Caspian depression (Astrakhan oblast)