Volume 104, Nº 6 (2025)

Descriptions of four new species of the genus Opisthocystis Sekera, 1911 are given: Opisthocystis zaytsevae Krivorotkin et Timoshkin sp. n., Opisthocystis strictostylus Krivorotkin et Timoshkin sp. n., Opisthocystis sekeri Krivorotkin et Timoshkin sp. n. and Opisthocystis tenuistylus Krivorotkin et Timoshkin sp. n., all of them endemic to Lake Baikal. The former three species were found in the coastal zone of the lake: O. zaytsevae: in the shallow waters of Bolshoy Ushkany Island; O. strictostylus: in the shallow waters of Ayaya Bay (northern basin) and opposite the village of Khuzhir (Olkhon Island, Maloye More Strait); O. sekeri: in the shallow waters of Onokochanskaya Bay (northern basin); O. tenuistylus was found on the underwater Akademichesky Ridge at a depth of about 350 m. Illustrated descriptions, differential diagnoses, brief information on their distribution and ecology are provided for all new species. New extensive information on the morphology and zoogeography of three rare and poorly studied endemic Baikal species of the same genus is provided: Opisthocystis multifidus (Nasonov, 1935), Opisthocystis octopropagostylus Lukhnev et Timoshkin, 2014, and Opisthocystis cf. umylinae Timoshkin, 2010. Brief illustrated descriptions and generalized information on their distribution are provided for all species. Revision of the taxonomic status of five Baikal species is proposed: Opisthocystis bilobatus Nasonov, 1935, Opisthocystis bicurvatus Nasonov, 1935 Opisthocystis campanulatus Nasonov, 1935, Opisthocystis irregularis Nasonov, 1935 and Opisthocystis trifida Nasonov, 1935. These species were described very briefly, and the drawings were very schematic. Based on the poor descriptions and schematic drawings, their reliable identification is impossible. In this regard, we are compelled to assign the status of nomen nudum to the above species of N. V. Nasonov.

The relatively large Indo-Malayan-Holarctic genus Pedetontus Silvestri, 1911 has so far included 33 described species. The genus has two subgenera: the nominative, Pedetontus s. str., with seven species (6 from North America and one from Kamchatka) and Verhoeffilis Paclt, 1972, with 26 species (three species from North America, 12 from the southeastern Palaearctic and 11 from the Indo-Malayan Region). Both subgenera are distinguished by the presence of two pairs of retractable vesicles on abdominal segments II–VI or II–V, respectively. Two new species of the latter subgenus are described from the Primorsky Territory of the Russian Federation: P. furuhjelmi sp. n., from Furugelm Island, and P. nigrus sp. n., from near Ussuriysk. Both these new species are very close to P. ussuriensis Kaplin, 1980, widespread in the Primorsky Territory, and P. silvestrii Mendes, 1993, from North Korea, but differ well in body length, the relative length of the antennae, the structure of the antennal flagella, the compound eyes, the paired ocelli, the maxillary and labial palps, the sternites, styli and coxites of abdominal segment IX, as well as by the chaetotaxy of the legs and urocoxites IX, and the ovipositor.

Two new species of gelechiid moths from the genus Gelechia Hübner are described: G. serratocornuta sp. n. from both Borneo, Malaysia and Mindanao Island, Philippines, and G. bifurcata sp. n. from Mindanao alone. The male genitalia of the new species have the uncus with either a single bifurcated projection or with two projections, these making them distinguished from the other species of this genus with known male genitalia.

During the rest periods of reindeers’ daytime we recorded “looking around”, “waking”, “dozing” and “sleeping”. Observations were made through a telescope from a distance sufficient to avoid disturbing the animals. We studied wild reindeer from the Snøhetta Mountains, Norway and the Spitsbergen Archipelago populations, feral reindeer from the Forelhogna Mountains Norway, the Wrangel Island populations and domestic reindeer from the Chukotka Peninsula. Reindeer from the Snøhetta Mountains, the Spitsbergen Archipelago and the Forelhogna Mountains populations were studied in winter to early spring (during the snowy period). Reindeer from the Wrangel Island and the Chukotka Peninsula were observed in June to July, during the snowless period. The duration of individual sleep episodes in the wild Snøhetta reindeer averaged about 4 minutes, vs 2 to 3 minutes in domestic and feral reindeer. Highly reliable differences in sleep episodes were found between the Snøhetta Mountains reindeer and other populations, except for the Forelhogna reindeer, whose differences, together with the Snøhetta Mountains reindeer, were only close to the reliable level (p = 0.076). The Wild Spitsbergen archipelago reindeer failed to differ from both the domestic Chukotka Peninsula reindeer and the feral Wrangel Island reindeer. For comparison, we used our data on the flight distance of reindeer when approached by humans in the same populations. Flight distances and the duration of sleep episodes in the Snøhetta Mountains reindeer differ from those all other populations, and the characteristics of the wild Spitsbergen archipelago reindeer were close to those of the domestic Chukotka Peninsula reindeer. Domestic reindeer of the Chukotka Peninsula were studied in the summer, when reindeer gather in dense masses to rest (herd size more than 3,000). Neighboring reindeer at rest often interfere with each other.

A detailed understanding of how weather influences the behavior of small mammals enhances our knowledge of species ecology and improves the interpretation of field study results. While the effect of weather on small mammal activity has long been recognized, research findings remain inconsistent, varying by species, season, and habitat. In the case of the Common vole, only a limited number of studies have examined this relationship, often focusing on a narrow range of weather parameters and yielding contradictory conclusions. This study aimed to investigate the influence of multiple weather factors on the activity (mainly nocturnal) of common voles in an open habitat during summer. To gather a sufficiently large dataset, an original technique for assessing small mammal activity by the footprint presence in systematically placed tracking devices was used. The study was conducted over one month across a 9-hectare area, where 961 tracking stations – each consisting of a plastic bottle, a tracking cartridge with waterproof ink, and bait – were deployed. The Common vole was confirmed as the dominant small mammal species in the study area through intensive trapping in the central part of the experimental plot. Over 10,571 device inspections and 6,910 vole visits were recorded. Weather data were recorded using an automatic weather station. The results demonstrated that wind, rain, higher temperatures, and increased humidity all contributed to greater activity in common voles. In contrast, elevated illumination levels reduced movement intensity. The methodology proved effective for obtaining large datasets to assess small mammal activity in monospecific communities.