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The aim of this study was to compare the parameters of the parasite species richness in common shrew Sorex araneus in periods its population highest and lowest population abundance. The analysis was mostly based on the estimation of differences in the species richness of helminth infracommunities and coefficients of the power law equation of species accumulation curves for parasite component communities. It was demonstrated that where common shrew abundances increased, the mean species richness of infracommunities decreased, but their β-diversity rose. Differences between the species accumulation curves for periods of shrew population highs and lows were dependent on the species richness of parasite infracommunities. When the host abundance was relatively low, individuals with average levels of parasite species richness prevailed in the population. In years with high shrew abundances, the species richness of their parasitic infracommunities was low.

The changes in the distribution and abundance of ixodid ticks (Ixodes persulcatus, I. ricinus) in St. Petersburg and the Leningrad Province in period of 1970-2018 are analyzed. The number of ticks in city parks and in the surrounding suburbs decreased by 6-9 times compared to the 70s of the 20th century, in the Leningrad Province by 1.5-10 times. Due to the increased anthropogenic pressure (increase in numbers, seasonal migrations) in the territory of the region bordering the city, the number of contacts of people with arthropods increases even with a low number of the latter, which leads to an increase in the number of tick bites affected and complicates the epidemic situation of tick-borne infections.

As a result of long-term (2010-2016 years) surveys, 12 species of ixodid ticks, parasitizing on agricultural animals in various landscapes of Southern Kazakhstan were detected. Hyalomma asiaticum asiaticum Sch. еt Schl. dominated in the general collections of agricultural animals (cattle and small cattle, horses, camels) in the desert landscape. Hyalomma scupense Sch. and H. anatolicum Koch. are dominated in the semi-desert, low-mountain steppe and tugay-agrarian places. Everywhere the largest number of ixodid ticks species was detected on the large cattle. The most infected with ticks are the cattle grazing in tugay-agricultural landscapes, the lowest infection was detected in low steppe and desert landscapes. The Congo-Crimean hemorrhagic fever virus was found in H. a. asiaticum, H. scupense, H. anatolicum, H. marginatum turanicum Pom., Dermacentor niveus Neum., Rhipicephalus (Boophilus) annulatus (Say). Ticks of Southern Kazakhstan are also the vectors and carriers of the causative agents of Q fever, tick-borne spotted fevers, piroplasmidosis and arboviruses.

The results of six-year studies (1983-1988) of shrew infestation with the nematode Calodium soricicola (Yokogawa et Nischigori, 1924) (Nematoda, Capillariidae) - a parasite of liver parenchyma of insectivorous mammals are presented. There are 6 species of the final nematode hosts (Sorex araneus L., S. caecutiens Laxmann, S. daphaenodon Thomas, S. minutus L., S. tundrensis Merriam and Neomys fodiens Pennant) detected in the subtaiga deciduous forest zone (northern regions of the Novosibirsk Region). The intensity of invasion of all insectivores by C. soricicola in 1983-1988 was 6.6 ± 0.8 % and changed from 3.2 ± 1.6 % in dry years to 9.1 ± 1.7 % in wet years. The most numerous and the most contaminated was the Sorex araneus, 10.3 ± 1.1 %, which is the main host of C. soricicola in the shrews community. Significant changes in its infestation by years were found - from 5.2 ± 1.7 % in dry years, to 17.4 ± 2.2 % in wet years. Other 5 species of shrews are classified as the second value hosts because of their small number and low contamination. The stages and timing of development of C. soricicola and C. hepaticum larvae were studied in laboratory conditions up to their invasive state. Infection of golden hamsters with invasive larvae of both nematode species showed that they easily infected C. hepaticum and did not infect by C. soricicola. The results obtained confirm the species independence of C. soricicola.

The great cormorant was widespread on Lake Baikal until the 1960s, it disappeared from it since the 1970s, and it quickly returned in the 2000s to this lake. Due to the fact that previously the trematode Petasiger radiatus (syn. Paryphostomum radiatum) was not observed in Lake Baikal, its description is given from the great cormorant from this water body.

The technique of preparation and storage of the genital apparatus of horseflies is developed. It is proposed to use 70 % alcohol along with the KOH (potassium hydroxide) to enforce softening of the muscles and ligaments of the genital structures. For the total preparations of the genital structures it is proposed to use CytosealTM 60 (USA) as the mounting medium instead of Сanadian balm.

The information of the scientific conference combined with a practical workshop for parasitologists, is given. The conference was held in Sevastopol, A.O. Kovalevsky Institute of Biology of the Southern Seas. Further information: https://cprs.marine-research.org/events/parasites2019/

A review of the book about the entomophatogenic nematodes (orders Tylenchida, Aphelenchida) of the world fauna. [In Russian].

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