ИСТИНА

Abiotic and biotic factors of the environment influence on all members of the parasitic system “virustick- host” and, in particular, determine the characteristics of the life cycle, physiology and behavior of ixodid ticks, which causes the appearance of interpopulation differences of ticks of the same species. The aim of this work was to study the interpopulation differences in behavior and biology of ixodid ticks. For that purpose, in 2017-2018 we collected ticks in 5 regions of the Russian Federation, where habitat of ticks of one species differed: Ixodes ricinus – Kaliningrad and Voronezh regions, I. persulcatus – Republic of Tuva and Karelia, and Dermacentor reticulatus – Kaluga and Voronezh regions. To compare ticks populations of one species, the following experiments were conducted: 1. Evaluation of the reaction of ticks to ethanolic extracts of plants collected in different biotopes with high number of ticks. As a result, differences in the reaction of different populations of ixodid ticks to some plant extracts were revealed. 2. Study of ticks” activity and tolerance to the repellent DEET (diethyltoluamide). To assess the activity of ticks, we analysed the height of ticks” trajectory, their path and speed over 3 minutes of observation on a tape impregnated with increasing concentrations of DEET. In our experiments, I. ricinus ticks from Voronezh region, D. reticulatus ticks from Kaluga region and I. persulcatus ticks from the Republic of Karelia showed higher activity and were more tolerant to the DEET, than ticks of the same species from Kaliningrad region, Voronezh region and Republic of Tuva, respectively. 3. Study of the resistance of ticks of the same species from different climatic regions to elevated temperatures. The experiments were carried out in a cold cabinet (4°C-17°C) and in a climatic chamber (22°C-30°C) according to Gilbert L. et al. (2014). We established significant difference in the reaction of different populations of ticks of the same species to the temperature increase. Populations of ticks collected from warm regions were the most resistant to high temperatures (above 26°C) and remained active longer. As a result of the experiments, we obtained data indicating interpopulation differences of ticks of the same species collected in different regions. This work was supported by the Russian Science Foundation grant #17-75-10173.