BEETLES (INSECTA: COLEOPTERA) IN UNDERSNOW UNINHABITED NESTS OF COMMON VOLE MICROTUS ARVALIS PALLAS, 1778 SENSU LATO (RODENTIA: CRICETIDAE) FROM SARATOV OBLAST

This article provides information about entomological monitoring of common vole’s ( Microtus arvalis Pallas, 1778 sensu lato) uninhabited nests under snow, during expedition around Khvalynsky District of Saratov Oblast in May of 2021 year. During the survey of nests had been discovered 22 beetle species from 10 families. Species Atomaria apicalis Erichson, 1846 is recorded for Saratov Oblast for the first time.

Control of Common Vole (Microtus arvalis) in Alfalfa Crops Using Reduced Content of Anticoagulants

The common vole, Microtus arvalis, which is prone to cyclic overpopulation, poses a significant threat to sustainable alfalfa production by either chewing shoots periodically or gnawing and damaging roots permanently. In areas with established vole colonies, the density of alfalfa plants was shown to decrease 55.3–63.4%. Simultaneously, the number of alfalfa shoots decreased by 60.9–71.7%. These experiments were conducted in compliance with an EPPO standard method in alfalfa fields at three geographically remote sites. The experiment tested the efficacy of the most widely used acute rodenticide zinc phosphide (2%), and anticoagulants applied at significantly reduced doses of active ingredients, i.e., bromadiolone (25 ppm) and brodifacoum (25 ppm), as well as a combination of these active ingredients at a low concentration (10 + 10 ppm). Three weeks after treatment, zinc phosphide and brodifacoum achieved the highest average efficacy, at 98.5% and 92.05%, respectively, while the average efficacy of the anticoagulant combination and bromadiolone was 87.2% and 75.5%, respectively. The achieved efficacy of baits based on brodifacoum and the combination of brodifacoum and bromadiolone in controlling common voles indicates their possible utilization in the field. Baits with 25 ppm of brodifacoum and the combination of bromadiolone and brodifacoum (10 + 10 ppm) showed satisfactory results and their introduction could significantly improve pest management programs for rodent control. At the same time, the use of anticoagulant rodenticides with reduced contents of active ingredients would significantly reduce their exposure to non-target animals, especially predators and vultures. By further improving the palatability of tested baits for target rodent species, their efficacy and safety of application would be significantly improved.

Cryptic species of the genus Microtus on the territory of Belarus: taxonomic position and distribution

The paper presents the original data of the chromosomal and molecular-genetic (by PCR typing) analysis of cryptic species of the genus Microtus on the territory of Belarus. The aim of the study is to perform chromosomal labeling of common vole populations in various localities in Belarus to identify Microtus arvalis s. l. twin species in natural ecosystems. Based on the karyological analysis, 2 representatives of the cryptic group were identified in the study area: the Eastern European vole (2р = 54, NF = 56) and the common vole (2р = 46, NF = 86). Also, to confirm the species identity of the twin species, a molecular genetic analysis was performed by PCR typing. It was established that one studied individual from the cryptic group Microtus arvalis s. l. belongs to the species Microtus rossiaemeridionalis. A fragment of the cyt b mitochondrial gene was amplified in the size of 469 bp in the remaining individuals (n = 105), and a fragment of the cytochrome b mitochondrial gene in the size of 842 was amplified, which indicates that these representatives belong to the Microtus arvalis form “arvalis”. In conclusion, the results of the work done are summed up, and tasks are set for further research of cryptic species of the genus Microtus in Belarus.

Helminths in Myomorph Rodents (Rodentia, Myomorpha) from the National Park “Smolny” and Its Surroundings (European Russia)

The National Park “Smolny” is a large forest area, located in the center of European Russia. The helminth fauna of myomorph rodents was studied for the first time within the National Park in 2018–2020. Rodents were examined by the method of complete helminthological dissection. A total of 30 species of parasites were recorded in 11 rodent species: 6 trematodes, 11 cestodes and 13 nematodes. The trematode Plagiorchis maculosus (Rudolphi, 1802) was found in Clethrionomys glareolus (Schreber, 1780) from the Russian fauna for the first time. Clethrionomys glareolus and Microtus arvalis (Pallas, 1779) are new hosts for P. maculosus and metacestode Versteria mustelae (Gmelin, 1790), respectively. The most widespread and eurybiont rodent species have the most diverse and rich helminth fauna, such as C/glareolus (14 species), Apodemus agrarius (Pallas, 1771) (12) and Sylvaemus uralensis (Pallas, 1811) (10). The helminth fauna is less diverse in Sylvaemus flavicollis (Melchior, 1834), M. arvalis (7 species each), Microtus agrestis (Linnaeus, 1761) (5), Microtus subterraneus (de Selys-Longchamps, 1836) (3), Sicista betulina (Pallas, 1779) (2) and Arvicola amphibius (Linnaeus, 1758) (1). Сomparative analysis the helminth fauna of small rodents from the National Park “Smolny” with micromammals from other regions of European Russia revealed that the high similarity with other areas reaches the helminth fauna of M. subterraneus, S. flavicollis, S. uralensis, S. betulina, A. amphibius and M. agrestis.

Cross-Context Responses to Novelty in Rural and Urban Small Mammals

The Anthropocene is the era of urbanization. The accelerating expansion of cities occurs at the expense of natural reservoirs of biodiversity and presents animals with challenges for which their evolutionary past might not have prepared them. Cognitive and behavioral adjustments to novelty could promote animals’ persistence under these altered conditions. We investigated the structure of, and covariance between, different aspects of responses to novelty in rural and urban small mammals of two non-commensal rodent species. We ran replicated experiments testing responses to three novelty types (object, food, or space) of 47 individual common voles (Microtus arvalis) and 41 individual striped field mice (Apodemus agrarius). We found partial support for the hypothesis that responses to novelty are structured, clustering (i) speed of responses, (ii) intensity of responses, and (iii) responses to food into separate dimensions. Rural and urban small mammals did not differ in most responses to novelty, suggesting that urban habitats do not reduce neophobia in these species. Further studies investigating whether comparable response patters are found throughout different stages of colonization, and along synurbanization processes of different duration, will help illuminate the dynamics of animals’ cognitive adjustments to urban life.

Seasonal and multiannual dynamics of rodent species number under the influence of climate factors and anthropic modifications

The research was carried out in agricultural experiment stations in the central area of the Republic of Moldova during a period of 35 years. It was determined that cyclic oscillations with an interval of 3-4 years are not typical of Microtus arvalis, as can be seen in other parts of the area. Intense anthropogenic influence determines the type of numerical dynamics. A certain periodicity is observed in the species Mus spicilegus, but during the last 30 years the dynamics has become acyclic. In the populations of the species Apodemus sylvaticus there was a more pronounced periodicity of the oscillation of the herd, once every two years.