Volume 59, Nº 6 (2025)

The paper presents new data on the species composition, distribution, and abundance of ixodid ticks of medical significance in the southwest of the Republic of Karelia (Lakhdenpokhsky District). Ticks were collected from vegetation in May–June and August 2015 and 2023–2025. Ixodes ricinus is widespread in the study area and predominates in the ixodid tick collections (94 %), with relative abundances of 0.6 and 2.0 specimens per flag-km in May–June and August, respectively. The second species, I. persulcatus, was recorded only in May–June in the northwest of the district with an abundance of 0.1 specimens per flag-km. Analysis of adult I. ricinus and I. persulcatus ticks for the presence of tick-borne encephalitis virus did not reveal positive results. Thus, the Lakhdenpokhsky region currently remains the only large area where I. ricinus is widespread and dominant. The epidemiological situation in this region is more favorable than in other areas of the republic, due to the low numbers of I. persulcatus and I. ricinus, as well as their infection with pathogens that cause particularly dangerous infections.

In the Southern Trans-Urals (Kurgan region), on the territory of the subtaiga, ixodid ticks of small mammals were studied for the first time. Pitfall traps with driving fences and trap lines were used to capture the animals. In just two years of accounting (2021 and 2024), 24860 cone-days and 21413 trap-days were worked out. 1711 animals were counted and analyzed. Ixodid ticks of six species have been recorded on 17 of the 19 species of shrews and rodents: Ixodes persulcatus, I. apronophorus, I. trianguliceps, Dermacentor reticulatus, D. marginatus and D. silvarum in the number of 5490 individuals. Standard parasitological indexes were used. In total, for two years of records, the ticks D. reticulatus and I. persulcatus dominated the territory of the subtaiga. We attribute this to the heterogeneity of the territories, the species composition and the ratio of feeders of the study points in the north of Shatrovsky and north of Kataysky districts. Our opinion on the second territory (the village of Lukina, Kataysky district) differs from the view of geobotanists, and this territory largely has a “forest-steppe” appearance, which could not but affect the ratio of ixodids in the community. The background species of small mammals of the studied territory (the common, Laxmann’s, and Eurasian pygmy shrews and voles – northern red-backed, short-tailed field, common, and tundra - fed the ixodid ticks most fully (all six species). The maximum abundance values for representatives of the genus Ixodes are typical for Myodes voles and shrews; Microtus voles fed more ticks of the genus Dermacentor.