Strobilocercosis (Hydatigera Taeniaeformis S.L., Larvae) in Mouse-Like Rodents From the Protected Areas of Mordovia

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.