New findings of spinturnicid mites (Mesostigmata: Gamasina: Spinturnicidae) from the Caucasus

The Caucasus is a large region in Eurasia consisting of four countries: Russia, Georgia, Azerbaijan, and Armenia. Although it is one of the biodiversity hotspots in the world, the bat ectoparasite fauna has been poorly studied. To promotionally fill in the gaps regarding bat ectoparasites, we conducted five field surveys on bats and their ectoparasites at nine localities within the region between April 2016 and March 2021. Eight species and subspecies of spinturnicid mites were recorded over the surveys: Eyndhovenia euryalis oudemansi, Spinturnix acuminata acuminata, S. emarginata, S. myoti, S. nobleti, S. plecotina, S. psi, and S. punctata. Among them, three species, Spinturnix emarginata, S. nobleti and S. punctate, are newly recorded from the Caucasus region, and one each of subspecies and species, Eyndhovenia euryalis oudemansi and S. plecotina, are newly recorded from Georgia. In addition, Myotis tschuliensis was recorded as a new host species of S. myoti.

A checklist of bat-associated macronyssid mites (Acari: Gamasina: Macronyssidae) of Russia, with new host and geographical records

The family Macronyssidae (Acari: Mesostigmata) comprises mostly obligate blood-sucking ectoparasites of bats (Mammalia: Chiroptera) and some other animals, such as small mammals, reptiles and birds. Here, we document and curate previously known data, and, based on our extensive survey, provide this article of bat-associated macronyssid mites of the Russian Federation. We record a total of 24 mite species belonging to 4 genera (Ichoronyssus, Macronyssus, Steatonyssus, and Cryptonyssus). Twenty-seven new host-parasite associations are reported. In addition, were provide data on five major Russian regions, for which bat-associated mite records were lacking.

New records of bat flies (Diptera: Nycteribiidae), with an updated checklist of the nycteribiids of Russia

We assembled a checklist by documenting and curating previously published data as well as previously unpublished records of bat flies from the Russian Federation. A total of 20 bat fly species are listed, belonging to 4 genera. Basilia mongolensis nudior Hůrka, 1972 and Basilia nattereri (Kolenati, 1857) are recorded from Russia for the first time. The following new host associations are reported: Basilia mongolensis nudior ex Myotis nattereri (Kuhl), Basilia nattereri ex Eptesicus nilssonii (Keyserling Blasius), Basilia rybini Hůrka, 1969 ex Myotis dasycneme (Boie) and Eptesicus nilssonii, and Nycteribia quasiocellata Theodor, 1966 ex Vespertilio murinus Linnaeus. We provide data on nine major Russian regions for which nycteribiid records were previously lacking.

[Shell Variability of the Terrestrial Mollusk Chondrula tridens (Pulmonata, Enidae) in the Forest-Steppe Zone of the Volga Upland]

Shell variability of the steppe mollusk Chondrula tridens from 18 micropopulations in the forest-steppe zone of the Volga Upland was studied. It was found that larger specimens of Ch. tridens with well-developed teeth inhabit the central and eastern parts of the territory. Specimens in the northwestern part of the upland are characterized by small shells, the highest degree of roundness, and mostly reduced teeth in the mouth. The main factors that determine variability in the size and proportions of shells are the average daily temperatures increasing from the northwest to the south, the reduction in the total precipitation, the decrease in the soil moisture content, and, possibly, the increased content of carbonates in the soil.

[Ecology of nutrition and differentiation of the trophic niches of bats (Chiroptera: Vespertilionidae) in floodplain ecosystems of the Samara Bend]

A complex analysis of the food range of 15 bat species inhabiting floodplain ecosystems of the Samara Bend has been performed. It is shown that, in bats, an important component of the structuring of their communities is the division of food resources. The guild structure and position of species in the trophic space are described. Seven food guilds consisting of nonspecialized and specialized species are distinguished. It is noted that most species are characterized by a wide overlapping of their trophic niches, which may be a consequence of their weak competition in an environment that is rich in food resources.

[Trophic ecology and predation of the greater noctule bat (Nyctalus lasiopterus) in Russia]

The trophic ecology of Nyctalus lasiopterus in the Samara Bend during 2008-2010 has been studied. It has been revealed that the main feeding stations for this species are old ecotonal black poplar stands and willow groves. N. lasiopterus keeps to opportunistic foraging by using easily accessible and properly sized food objects. Having analyzed 129 fecal samples, we singled out 10 categories of food objects belonging to six orders of insects. The representatives of Lepidoptera constitute the major part of the ration. Their abundance rates undergo asynchronous changes relative to each other. Homoptera and Neuroptera are found more rarely in the feces. Orthoptera and Diptera are extremely rare. Besides insects, bird feathers were found in 14 faecal samples of N. lasiopterus. They made up from 60 to 90% of the total fecal mass.

[Single and group organizations of individual animals in the community of bats (Chiroptera: Vespertilionidae) hibernating in artificial caves of the Samarskaia Luka]

The spatial arrangement of individual bats of seven species and their tendency to form groups were studied in artificial caves of the Samara Luka during five winter periods (1999 and 2003-2006). It was demonstrated that formation of dense groups did not depend on the hibernating population size or density and was related to the biological characteristics of the species. Most Myotis brandtii and M. dasycneme (60-80% of the populations) wintered in groups. M. mystacinus, M. daubentonii, Pecotus auritus, M. nattereri, and Eptesicus nilssonii usually wintered singly (87% of the animals). In M. brandtii and M. dasycneme, as many as 78% of individual animals were in conspecific groups, whereas this proportion for the other species was no higher than 11%. All pairs of species exhibited negative assortativeness, which indicated a higher preference of spending winter in conspecific groups than in groups containing representatives of other species. Estimation of the ratios between groups containing animals of one and several species showed that conspecific groups were prevailing in M. brandtii and M. dasycneme, whereas all other species usually formed mixed groups.

[Spatial structure of the community of bats (Chiroptera: Vespertilionidae) hibernating in artificial caves of Samarskaya Luka]

Specific features of the spatial distribution and localization of bats have been studied during their hibernation in artificial caves of Samarskaya Luka. The proportion of cave area occupied by bats varies from 70 to 93% in large caves (> 60000 m2), decreasing to 50% in medium-sized caves (10000-60000 m2) and to less than 30% in small caves (< 10000 m2). Approximately 9% of bats choose sites near cave openings, up to 25% prefer central parts, but most bats (about 66%) concentrate in the deepest parts of caves. Among wintering species, higher rates of occurrence and shelter occupancy are characteristic of Plecotus auritus. Myotis daubentonii, and M. mystacinus, whereas M. dasycneme and M. brandtii show the highest degree of aggregation. The optimal temperature range for the wintering of all bat species is 2-4 degrees C. Myotis brandtii, Eptesicus nilssonii, and M. daubentonii prefer to hibernate in open spaces of cave ceilings; M. mystacinus. E. serotinus, and Pl. auritus usually occupy the middle and upper parts of walls; while M. dasycneme and M. nattereri occur mainly in hollows on ceilings.

[Species structure and dynamics of bat communities (Chiroptera: Vespertilionidae) hibernating in artificial caves of Samara Luka]

Long-term data on the composition and absolute and relative abundance of eight bat species hibernating in artificial caves of Samara Luka are considered. About 13,000 hibernating individuals are annually accounted there. The relative abundance of the species decreased in the following order: Myotis brandtii (35%), Plecotus auritus (20%), M. daubentonii (13%), M. mystacinus (13%), Eptesicus nilssonii (8%), M. dasycneme (8%), and M. nattereri (2%). Singular E. serotinus were recorded not every year. The number of hibernating animals in pits was proportional to their size and the number of shelters. Bats used previously chosen shelters and were never found in adjacent caves. The maximum species diversity (H') and evenness (E) were observed in bat communities in medium-sized caves. One of the main factors of increasing abundance of hibernating bats in abandoned pits is their gradual colonization by the animals.

[State of cellular immunity effectors of the lung in inhalation exposure to low-transportable Pu-239]

The reduction of populations of lung cell immunity effectors as well as changes in their cytotoxic and phagocytic activity was observed in rats after inhalation exposure to polymeric 239Pu. Dose-response curves described as a function of absorbed dose of alpha-irradiation in lung.

[The recovery of humoral immunity after the long-term action of tritium oxide at different irradiation levels]

Dynamics of recovery of humoral immunity of CBA mice was studied 1, 3, 6 and 12 months after termination of long-term exposure to tritium oxide at various levels of absorbed doses (3, 5 and 9 Gy) and dose rates (3.3, 4.9 and 9.2 cGy.day-1). A severer and more stable residual radiation damage was observed in the department of lymphocyte precursors. A considerable decrease in the content of antibody producers was due to the lymphoid tissue hypoplasia. There was a direct relationship between the immunodeficiency and dose rate and total absorbed dose of beta radiation.