During the 2023 field season, the trematode fauna in 398 birds of 38 species of the Samara Region fauna was studied for the first time using the method of complete helminthological dissection. Trematodes of the genus Prosthogonimus were recorded in birds from only 3 of 12 districts studied. Two species, Prosthogonimus ovatus and P. cuneatus, were recorded in 3 species of avian fauna: the great tit, the chaffinch and the common bee-eater. The total infection of birds with Prosthogonimus parasites was 2.5%, 0.06 specimens. Trematode Prosthogonimus cuneatus was recorded for the first time in the Samara Region. The common bee-eater was indicated as a new host for Prosthogonimus ovatus. Wild birds of the fauna in the Middle Volga Region served as final obligate hosts of trematodes of the genus Prosthogonimus which are pathogenic for birds. Based on our study, the host range for Prosthogonimus spp. in the Middle Volga Region included 46 species of the avian fauna. Prosthogonimus found in wild birds in the Samara Region indicates a prosthogonimosis focus existing in the Region. Our data expand the understanding of the distribution in the Russian Federation of Prosthogonimus ovatus and P. cuneatus pathogenic for wild birds and poultry.
The main intermediate hosts of the cestode Hydatigera taeniaeformis (Batsch, 1786) sensu lato (s. l.) are mouse-like rodents. During the 2018-2022 field seasons, the helminth fauna in 2.812 specimens of 14 species of mouse-like rodents was studied using the method of complete helminthological dissection in two protected areas of the Republic of Mordovia: the Mordovia State Nature Reserve (1.534 rodents studied) and Smolny National Park (1.278 rodents). The micromammals were captured using steel spring traps. Trap lines consisted of 20 steel spring traps located in 10 m intervals. Strobilocerci Hydatigera taeniaeformis s. l. was only found in 5 rodent species from 14 studied rodents: pygmy wood mouse Sylvaemus uralensis, yellow-necked mouse Sylvaemus flavicollis, striped field mouse Apodemus agrarius, bank vole Clethrionomys glareolus, and pine vole Microtus subterraneus. The total H. taeniaeformis s. l. larvae infection rate in the rodents was 1.2% (34 rodents infected), and an abundance index was 0.02 specimens (42 larvae collected). Hydatigera taeniaeformis s. l. larvae were recorded in the Smolny National Park for the first time. The pine vole M. subterraneus was recorded as the intermediate host for such cestode species for the first time. Our data enhance the understanding of the strobilocercosis spread among mouse-like rodents of the Middle Volga Region fauna.
