Zaika V.V. 2025. The caddisflies (Insecta, Trichoptera) of the Us river basin in the Western Sayan mountains, Russia // Euroasian Entomological Journal. Vol.24. No.4: 191–196 [in English].
Tuvinian Institute for Exploration of Natural Resources of Siberian Branch of the Russian Academy of Sciences, Internatsionalnaya Str. 117а, Tyva Republic, Kyzyl 667007 Russia; Tuvan State University, Lenina Str. 36, Tyva Republic, Kyzyl 667000 Russia. E-mail: odonta@mail.ru
doi 10.15298/euroasentj.24.04.03
ABSTRACT. This study is based on the author’s collection of data from the Us river basin between 2013 and 2023. The Us River is a right tributary of the Yenisei River, and the Aradanka and Koyard tributaries belong to the southern macroslope of the Western Sayan. The study covered 53 km of the river’s total length of 236 km, primarily during the months of June to October. A total of 387 larvae, 316 male imagoes and 692 female imagoes belonging to 54 species were collected. The most common species found in all river sections were Brachycentrus americanus (Banks, 1899) and Apatania stigmatella (Zetterstedt, 1840). The Glossoma ailtaicum (Martynov, 1914) species were recorded as being widespread. A comparison of the species composition of the Nizhnyaya Buiba River and the Us River according to the Sorensen-Chekanovsky index showed an equality of 0.3. The similarity of the Us river’s species composition with that of the Aradanka and Koyard rivers is lower, at 0.15 respectively. The Us River’s species diversity similarity index with the rivers of the northern macroslope of the Western Sayan is 0.41, and with the Upper Yenisei it is 0.40.
KEY WORDS: Trichoptera, fauna, the Us river basin, Western Sayan.