Abstract
<jats:p>In 2019 and 2025, in the territory of the Untorsky nature reserve (Oktyabrsky district, Khanty-Mansi Autonomous Okrug - Yugra), recorded of small mammals (insectivores and rodents) and their ectoparasites were carried out during the summer-autumn period. A total of 966 individuals of small mammals of 12 species were registered, from which 1,470 specimens of ectoparasites of 31 species were collected. Among them are 8 species of parasitic gamasid mites, 2 species of ixodid ticks, 3 species of lice and 18 species of fleas. To identify a more complete composition of small mammals (hosts of ectoparasites), two methods of surveys were used: ditches with pitfalls or polyethylene guide fences and trap lines. In terms of the species composition of hosts and ectoparasites parasitizing them, ditches with pitfalls or polyethylene guide fences were more effective. Among gamasid mites, regardless of the method of catching insectivores and rodents, Laelaps algericus dominated. In the absence of water voles in the records (depression of numbers), their specific parasite Laelaps muris fed on the root vole. Two species of ixodid ticks – Ixodes persulcatus and I. apronophorus, typical for the northern taiga of Western Siberia, were also noted in the territory of the Untorsky nature reserve, with I. persulcatus dominating. Among the lice of wild mammals, Hoplopleura acanthopus was overwhelmingly predominant, with H. edentula and Polyplax hannswrangeli accounting for less than 2%. The fleas' main fidder were the northern red-backed vole, the common shrew, and the root vole. Most registered ectoparasites are involved to varying degrees in the circulation of infectious agents in natural foci of tularemia, tick-borne encephalitis and tick-borne borreliosis.</jats:p>