Microtus Arvalis Research Articles

Гамазовые клещи (Mesostigmata: Gamasina), обнаруженные в нежилых подснежных гнездах обыкновенной полевки Microtus arvalis s. l. (Rodentia: Cricetidae) на территории Духовницкого района Саратовской области

The results of a parasitological study of uninhabited nests of the common vole Microtus arvalis s.l., collected on territory of the Dukhovnitsky district of the Saratov Region in April 2019 are presented. We identified nine species of gamasid mites associated with nests of the common vole. For the first time, Laelaps algericus Hirst., 1925, was recorded for the fauna of the Dukhovnitsky district of the Saratov Region. We found two new to Saratov region genera of free-living mites (without species identification): Laelaspis A. Berlese, 1903 (Laelapidae) and Neoseiulus A. M. Hughes, 1948 (Phytoseiidae). The study has shown that facultative hematophages dominate numerically, and free-living forms predominate in terms of species composition. All hematophagous species found belong to the typical ectoparasites of the common vole, they have wide distribution and are common species for the fauna of the Saratov region.

Molecular Characterisation and Phylogeny of Tula Virus in Kazakhstan.

Orthohantaviruses are zoonotic pathogens that play a significant role in public health. These viruses can cause haemorrhagic fever with renal syndrome in Eurasia. In the Republic of Kazakhstan, the first human cases were registered in the year 2000 in the West Kazakhstan region. Small mammals can be reservoirs of orthohantaviruses. Previous studies showed orthohantavirus antigens in wild-living small mammals in four districts of West Kazakhstan. Clinical studies suggested that there might be further regions with human orthohantavirus infections in Kazakhstan, but genetic data of orthohantaviruses in natural foci are limited. The aim of this study was to investigate small mammals for the presence of orthohantaviruses by molecular biological methods and to provide a phylogenetic characterization of the circulating strains in Kazakhstan. Small mammals were trapped at 19 sites in West Kazakhstan, four in Almaty region and at seven sites around Almaty city during all seasons of 2018 and 2019. Lung tissues of small mammals were homogenized and RNA was extracted. Orthohantavirus RT-PCR assays were applied for detection of partial S and L segment sequences. Results were compared to published fragments. In total, 621 small mammals from 11 species were analysed. Among the collected small mammals, 2.4% tested positive for orthohantavirus RNA, one sample from West Kazakhstan and 14 samples from Almaty region. None of the rodents caught in Almaty city were infected. Sequencing parts of the small (S) and large (L) segments specified Tula virus (TULV) in these two regions. Our data show that geographical distribution of TULV is more extended as previously thought. The detected sequences were found to be split in two distinct genetic clusters of TULV in West Kazakhstan and Almaty region. TULV was detected in the common vole (Microtus arvalis) and for the first time in two individuals of the forest dormouse (Dryomys nitedula), interpreted as a spill-over infection in Kazakhstan.

Diversity of Borrelia burgdorferi sensu lato in ticks and small mammals from different habitats

BackgroundIxodid ticks are important vectors for zoonotic pathogens, with Ixodes ricinus being the most important in Europe. Rodents are hosts of immature life stages of I. ricinus ticks and are considered main reservoirs for tick-borne pathogens, e.g. Borrelia burgdorferi. The aim of this study was to analyse the prevalence as well as genospecies and sequence type (ST) diversity of Borrelia burgdorferi sensu lato in ticks and small mammals from central Germany and to elaborate on the influence of environmental and/or individual host and vector factors on Borrelia prevalence.MethodsAfter species identification, 1167 small mammal skin samples and 1094 ticks from vegetation were screened by B. burgdorferi sensu lato real-time polymerase chain reaction, and positive samples were characterized by multilocus sequence typing. Generalized linear (mixed) models were used to estimate how seasonality, small mammal species/tick life stage and habitat affect individual infection status.ResultsIn total, 10 small mammal species and three tick species, Ixodes ricinus, Ixodes inopinatus (both considered members of the I. ricinus complex) and Dermacentor reticulatus, were investigated. Borrelia DNA was detected in eight host species, i.e. the striped field mouse (Apodemus agrarius), the yellow-necked field mouse (Apodemus flavicollis), the wood mouse (Apodemus sylvaticus), the water vole (Arvicola amphibius), the bank vole (Clethrionomys glareolus), the field vole (Microtus agrestis), the common vole (Microtus arvalis), and the common shrew (Sorex araneus). Two species were Borrelia negative, the greater white-toothed shrew (Crocidura russula) and the pygmy shrew (Sorex minutus). The average prevalence was 6.2%, with two genospecies detected, Borrelia afzelii and Borrelia garinii, and at least three STs that had not been previously reported in small mammals. Borrelia prevalence in small mammals did not differ between seasons. Six genospecies of Borrelia—Borrelia afzelii, Borrelia valaisiana, Borrelia garinii, Borrelia lusitaniae, Borrelia spielmanii, and Borrelia burgdorferi sensu stricto—and 25 STs of Borrelia, of which 12 have not been previously described at all and five have not been previously reported in Germany, were detected in 13% of I. ricinus complex ticks. Prevalence was highest in adult females (25.3%) and lowest in nymphs (11.4%). Prevalence was significantly higher in ticks from grassland (16.8%) compared to forests (11.4%).ConclusionsThe high level of small mammal diversity in this region of Germany seems to be reflected in a wide variety of genospecies and STs of B. burgdorferi.Graphical abstract

Viral Zoonoses in Small Wild Mammals and Detection of Hantavirus, Spain.

We screened 526 wild small mammals for zoonotic viruses in northwest Spain and found hantavirus in common voles (Microtus arvalis) (1.5%) and high prevalence (48%) of orthopoxvirus among western Mediterranean mice (Mus spretus). We also detected arenavirus among small mammals. These findings suggest novel risks for viral transmission in the region.

Spatiotemporal Variation of Small Mammal Communities in Commercial Orchards across the Small Country

The diversity of small mammal communities is a measure of the sustainability of habitats, especially agricultural ones. Based on 2018–2020 data from 18 sites in Lithuania, we analysed factors related to diversity of such a community, specifically the relative abundances and proportions of common vole, striped field mouse, yellow-necked mouse, and bank vole. We assessed the influence of location (central, northern, eastern, southern, and western parts of the country), habitat type (orchards, berry plantations, control habitats), the year and season. The model explained 14.8–33.4% of the listed parameters with p < 0.005 or higher, with the exception of the dominance index and the proportion of the common vole. Time factor (year and season, p < 0.001) and site location (p < 0.05) had the highest influences, while that of habitat type was less significant. The results of this and the former research suggest that commercial orchards play a role in maintaining the diversity and abundance of small mammal communities in the agrolandscapes.

Mammal extinction facilitated biome shift and human population change during the last glacial termination in East-Central Europe

The study of local extinction times, together with the associated environmental and human population changes in the last glacial termination, provides insights into the causes of mega- and microfauna extinctions. In East-Central (EC) Europe, groups of Palaeolithic humans were present throughout the last glacial maximum, but disappeared suddenly around 15,200 cal BP. In this study cave sediment profiles dated using radiocarbon techniques and a large set of mammal bones dated directly by AMS 14C were used to determine local extinction times. These were, in turn, compared to changes in the total megafauna population of EC Europe derived from coprophilous fungi, the Epigravettian population decline, quantitative climate models, pollen and plant macrofossil inferred climate, as well as to biome reconstructions. The results suggest that the population size of large herbivores decreased in the area after 17,700 cal BP, when temperate tree abundance and warm continental steppe cover both increased in the lowlands. Boreal forest expansion started around 16,200 cal BP. Cave sediments show the decline of narrow-headed vole and arctic lemming populations specifically associated with a tundra environment at the same time and the expansion of the common vole, an inhabitant of steppes. The last dated appearance of arctic lemming was at ~ 16,640 cal BP, while that of the narrow-headed vole at ~ 13,340, and the estimated extinction time of woolly mammoth was either at 13,830 (GRIWM) or 15,210 (PHASE), and reindeer at 11,860 (GRIWM) or 12,550 cal BP (PHASE). The population decline of the large herbivore fauna slightly preceded changes in terrestrial vegetation, and likely facilitated it via a reduction in the intensity of grazing and the concomitant accumulation of plant biomass. Furthermore, it is possible to conclude that the Late Epigravettian population had high degree of quarry-fidelity; they left the basin when these mammals vanished.

Differential temperature effects on photoperiodism in female voles: A possible explanation for declines in vole populations.

Many mammalian species use photoperiod as a predictive cue to time seasonal reproduction. In addition, metabolic effects on the reproductive axis may also influence seasonal timing, especially in female small, short‐lived mammals. To get a better understanding of how annual cycling environmental cues impact reproductive function and plasticity in small, short‐lived herbivores with different geographic origins, we investigated the mechanisms underlying integration of temperature in the photoperiodic‐axis regulating female reproduction in a Northern vole species (tundra vole, Microtus oeconomus) and in a Southern vole species (common vole, Microtus arvalis). We show that photoperiod and temperature interact to determine appropriate physiological responses; there is species‐dependent annual variation in the sensitivity to temperature for reproductive organ development. In common voles, temperature can overrule photoperiodical spring‐programmed responses, with reproductive organ mass being higher at 10°C than at 21°C, whereas in autumn they are less sensitive to temperature. These findings are in line with our census data, showing an earlier onset of spring reproduction in cold springs, while reproductive offset in autumn is synchronized to photoperiod. The reproductive organs of tundra voles were relatively insensitive to temperature, whereas hypothalamic gene expression was generally upregulated at 10°C. Thus, both vole species use photoperiod, whereas only common voles use temperature as a cue to control spring reproduction, which indicates species‐specific reproductive strategies. Due to global warming, spring reproduction in common voles will be delayed, perhaps resulting in shorter breeding seasons and thus declining populations, as observed throughout Europe.

FEATURES OF THE LIFE CYCLE OF ALARIA ALATA (TREMATODA, STRIGEIDIDA) IN THE ECOLOGICAL CONDITIONS OF THE CENTRAL BLACK-SOIL REGION: PARATENIC HOSTS

New data were obtained on the implementation of the Alaria alata life cycle in the conditions of the Central Black-Soil Region. Based on the materials of our research, paratenic hosts of A. alata were identified: Natrix natrix, Vipera berus, Neovison vison, Myodes glareolus. Alaria mesocercariae were observed in all the studied Natrix natrix (27 specimens) and Vipera berus (7 specimens) with the extensiveness of infestation (EI) of 100%. Intensity of infestation (II) averaged 12.0 specimens in N. natrix (2–18 specimens) and 261.3 specimens (12–627 specimens) in V. berus. Alaria mesocercariae were found in the Neovison vison with localization mainly in the esophagus, subcutaneous tissue, striated muscles, and serous integuments. The maximum number of mesocercariae was found in the esophagus – 50 specimens. The M. glareolus was registered as a paratenic host of A. alata with localization of mesocercariae in the M. glareolus in the esophagus. Taking into account the earlier helminthofaunistic materials on the study of the life cycle of A. alata conducted in the Voronezh Region and adjacent areas, other species of mammals were also registered as paratenic hosts. Mesocercariae have been recorded in Sus scrofa, mouse-like rodents: M. glareolus and Microtus arvalis, mice: Apodemus uralensis, Apodemus flavicollis and A. agrarius, Dryomys nitedula and Castor fiber.

Selection of scenarios for landscape-level risk assessment of chemicals: case studies for mammals

BackgroundFor landscape-level risk assessments of pesticides, the choice of the scenario is a key question, since it determines the outcome of a risk assessment. Typically, the aim is to select a realistic worst-case scenario. In the present study, landscapes from an area with a high proportion of cereal fields in France were analysed and simulations with population models for wood mouse, common vole, brown hare and European rabbit were conducted to understand if the worst-case character regarding pesticide exposure and population survival can be determined based on landscape features alone. Furthermore, it was analysed which landscape features relate with population survival and the magnitude of effects due to pesticide application. Answers to these question may help to decide whether landscape scenarios can be selected based on expert decision and whether the same scenarios may be used for different species or not.ResultsThere were species-specific landscape features relating to long-term population survival. A landscape that is worst-case for one species, was not necessarily worst-case for another. Furthermore, landscapes that were worst-case regarding population survival were often not worst-case regarding the magnitude of effects resulting from pesticide application. We also found that small landscapes were sometimes, but not always worst-case compared to larger landscapes. When small landscapes were worst-case, this was typical because of the artificial borders of the digitised landscape.ConclusionsLandscape analyses can help to obtain an approximate impression of the worst-case character of a landscape scenario. However, since it was difficult to consistently and reliably do this for single landscapes, it may be advisable to use a set of different landscapes for each risk assessment, which covers the natural variability. Depending on whether population survival shall be ensured or the magnitude of effects due to pesticides, different landscape structure and composition needs to be considered to establish a worst-case landscape scenario.

Ecological indices and factors influencing communities of ectoparasitic laelapid mites (Acari, Mesostigmata, Laelapidae) of small mammals in Lithuania.

Family Laelapidae is an ecologically diverse group that includes free-living species and parasites of vertebrates and invertebrates. At least seven genera in this family are associated with small mammals. In this study, ectoparasitic laelapid mites of rodents and shrews were investigated in Lithuania. In total, 2,274 small mammal specimens of 12 species were trapped and 6,089 laelapid mites were collected. The updated list of ectoparasitic mites in Lithuania included 21 mite species. Seven mite species were identified as highly specific for a host species or genus, one species was moderately specific, and four mite species were assigned to generalist parasites. All host species had one or two superdominant mite species. The prevalence and mean intensity varied significantly depending on host species and habitat. We analyzed the influence of the host (species, sex, age) and environmental factors (landscape morphology type, habitat, anthropogenic effect) on the abundance of the mite community and most numerous mite species, as well as the impact of the host community (Shannon's diversity index, species richness, host abundance) on mean abundance of the mite community. Only particular host species (Apodemus flavicollis, Microtus agrestis, and Microtus arvalis) and habitats (pastures, mixed forests) influenced the abundance of mites.

An evaluation of individual seasonal changes in dental macro- and mesowear of wild-caught common vole (Microtus arvalis sensu lato) by the intravital impressions method

An evaluation of individual seasonal changes in dental macro- and mesowear of wild-caught common vole (Microtus arvalis sensu lato) by the intravital impressions method

Effectiveness of wire netting fences to prevent animal access to road infrastructures: an experimental study on small mammals and amphibians

Transport infrastructures, such as highways, disrupt animal migrations and cause roadkill. To mitigate the latter problem, fences have been built but their effectiveness has rarely been tested under controlled conditions. Here, we tested the effectiveness of the most commonly used fence in France and probably in Europe (wire netting fence) to block animals. We tested the wire netting fence, with and without a structural modification (i.e. an overhang), with three small mammalian species (the European hamster: Cricetus cricetus Linnaeus, 1758; the common vole: Microtus arvalis Pallas, 1778 & the wood mouse: Apodemus sylvaticus Linnaeus, 1758) and two amphibian species (the marsh frog: Pelophylax ridibundus Pallas, 1771 & the European green toad: Bufotes viridis Laurenti, 1768). During testing, all small vertebrate species tested were placed into an arena, from which they could only escape by crossing the wire netting fence. Without an overhang, almost all adult individuals of all tested species were able to climb over a 30 to 40 cm high wire netting fence. Furthermore, the addition of an 8 cm long overhang at the top of the fence stopped the amphibian species tested but not the most agile mammalian species, such as the hamster and the wood mouse. Based on these results, we do not support the construction of wire netting fences along roads as a measure to stop small animals from crossing. We recommend the use of more effective and durable fences, which, in addition, can be associated with wildlife passages to reconnect isolated populations.

Genetic Diversity of Species of Microtus Generic Group (Arvicolinae, Rodentia): New Data from the Greater Caucasus.

Using the cytochrome b gene (1143 bp), species identification and the phylogenetic analysis of voles of the generic group Microtus from the eastern part of the Greater Caucasus, including the Ismayilli, Khizi, and Balakan Districts of Azerbaijan, have been carried out. Three species, the Major's pine vole (M.majori), the social vole (M. socialis), and the common vole (M. arvalis form obscurus), have been identified, and five new haplotypes have been described for them. Genetic analysis with the inclusion of the new data showed that for each of the species, the physiographic conditions of the Greater Caucasus played a certain role (isolation, migration route or refugium) during the formation of the modern genetic structure. The obtained results indicate that any new data from the Caucasus could be of critical importance for the reconstruction of the evolutionary history of the modern biodiversity both within the region itself and in adjacent territories.

Classification of airborne multispectral imagery to quantify common vole impacts on an agricultural field.

BACKGROUNDThe common vole (Microtus arvalis) is a very destructive agricultural pest. Particularly in Europe, its monitoring is essential not only for adequate management and outbreak forecasting, but also for accurately determining the vole's impact on affected fields. In this study, several alternatives for estimating the damage to alfalfa fields by voles through unmanned vehicle systems (UASs) and multispectral cameras are presented. Currently, both the farmers and agencies involved in the integrated pest management (IPM) programs of voles do not have sufficiently precise methods for accurate assessments of the real impact to crops.RESULTSOverall, the four multispectral classification methods presented showed similar performances. However, the normalized difference vegetation index (NDVI)‐based segmentation exhibited the most accurate and reliable appraisal of the affected areas. Nevertheless, it must be noted that the simplest method, which was based on an automatic classification, provided results similar to those obtained by more complex methods. In addition, a significant direct relationship was found between the number of active burrows and damage to the alfalfa canopy.CONCLUSIONUnmanned vehicle systems, combined with multispectral imagery classification, are an effective and easily transferable methodology for the assessment and monitoring of common vole damage to agricultural plots. This combination of methods facilitates decision‐making processes for IPM control strategies against this pest. © 2022 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Cocirculation of Leptospira spp. and multiple orthohantaviruses in rodents, Lithuania, Northern Europe.

In Europe, zoonotic Leptospira spp. and orthohantaviruses are mainly associated with specific rodent hosts. These pathogens cause febrile human diseases with similar symptoms and disease progression. In Lithuania, the presence of Dobrava-Belgrade orthohantavirus (DOBV), Tula orthohantavirus (TULV) and Leptospira spp. in rodent reservoirs is still unknown, and Puumala orthohantavirus (PUUV) was detected in bank voles (Clethrionomys glareolus) at only one site. Therefore, we collected and screened 1617 rodents and insectivores from Lithuania for zoonotic (re-)emerging Leptospira and orthohantaviruses. We detected Leptospira DNA in six rodent species, namely striped field mouse (Apodemus agrarius), yellow-necked mouse (Apodemus flavicollis), bank vole, common vole (Microtus arvalis), field vole (Microtus agrestis) and root vole (Microtus oeconomus). Leptospira DNA was detected with an overall mean prevalence of 4.4% (range 3.7%-7.9% per rodent species). We detected DOBV RNA in 5.6% of the striped field mice, PUUV RNA in 1% of bank voles and TULV RNA in 4.6% of common voles, but no Leptospira DNA in shrews and no hantavirus-Leptospira coinfections in rodents. Based on the complete coding sequences of the three genome segments, two distant DOBV phylogenetic lineages in striped field mice, one PUUV strain in bank voles and two TULV strains in common voles were identified. The Leptospira prevalence for striped field mice and yellow-necked mice indicated a significant negative effect of the distance to water points. The detection of (re-)emerging human pathogenic Leptospira and three orthohantaviruses in rodent reservoirs in Lithuania calls for increased awareness of public health institutions and allows the improvement of molecular diagnostics for pathogen identification.

The elemental composition of small mammals in a commercial orchard–meadow system

We analyze concentrations of various elements in small mammals from commercial orchards and berry plantations and test differences between them depending on species, individual body mass, age, gender, type and age of crop and intensity of applied agricultural measures. Skinned front legs (muscle and bones) were used to register the presence and concentration of Ca, Cd, Mo, Ni, Se, Ag, As, Be, Bi, Co, Cr, Cu, Fe, Ga, Mg, Mn, Pb, Sr, U, V and Zn. The most abundant species were common vole (Microtus arvalis), yellow-necked (Apodemus flavicollis) and striped field (A. agrarius) mice. The maximum recorded concentrations exceeded the minimums by 1.7–7.7 times in Mg, Zn, Cu, Ga, Ni and Ca, and 11.0–23.2 times in Mn, Be, Mo, Co, Sr, V, Pb and As. The hypothesis that the use of fertilization and pesticides in commercial orchards should induce differences in the elemental concentrations between crop areas and control habitats was confirmed by the higher concentrations of Cu, Mn, Bi, Co, Cr, Fe, Ni, Sr and Pb in rodents from the crop areas. Spatially controlled generalized linear mixed model confirmed the cumulative influence of species and crop, explaining 30–80% of the distribution of Ca, Ni, Co, Cu, Ga, Mn, Pb and U. The effect of species and the age of the individual was significant for Ni, Co, Cu, Fe, Ga, Mn and Pb, while effect of gender was not expressed. Depletion of Cu in older individuals was found in all three species. With species as a grouping factor, the effect of crop type and the intensity of agricultural practices were significant factors in the accumulation of Ca, Ni, Co, Cu, Ga, Mn and Pb, while effect of crop age was not expressed. The obtained elemental concentrations in rodents indicated orchards to be cleaner than heavy polluted areas.

Rodent fertility in commercial orchards in relation to body mass and body condition

Although rodents are recognized as pests, they are still an important part of agricultural ecosystems. In 2018–2020, we snap-trapped small mammals in Lithuania in 18 commercial orchards (apple and plum orchards, currant and raspberry plantations) and in adjacent control habitats. We aimed to discover whether the litter size of the six most abundant rodent species depended on season, on female body mass and/or on fitness. Litter size in common and root voles was smaller in habitats with a higher intensity of agricultural practices. Compared to summer, observed litter size in autumn significantly decreased in common voles (from 5.6 to 4.8) and yellow-necked mice (from 5.8 to 4.6). In autumn, litter size and female body mass was positively correlated in all rodent species, while in summer this was characteristic to root voles (r = 0.67, p < 0.05, 45% of variation of the litter size explained) and yellow-necked mice (r = 0.53, p < 0.005, 27% respectively) only. Female body condition index and litter size correlations were weak. Potential litter size exceeded the observed rate and breeding failures were observed in all species, with the highest percentage in root, bank and common voles.

Fitness, risk taking, and spatial behavior covary with boldness in experimental vole populations.

Individuals of a population may vary along a pace‐of‐life syndrome from highly fecund, short‐lived, bold, dispersive “fast” types at one end of the spectrum to less fecund, long‐lived, shy, plastic “slow” types at the other end. Risk‐taking behavior might mediate the underlying life history trade‐off, but empirical evidence supporting this hypothesis is still ambiguous. Using experimentally created populations of common voles (Microtus arvalis)—a species with distinct seasonal life history trajectories—we aimed to test whether individual differences in boldness behavior covary with risk taking, space use, and fitness. We quantified risk taking, space use (via automated tracking), survival, and reproductive success (via genetic parentage analysis) in 8 to 14 experimental, mixed‐sex populations of 113 common voles of known boldness type in large grassland enclosures over a significant part of their adult life span and two reproductive events. Populations were assorted to contain extreme boldness types (bold or shy) of both sexes. Bolder individuals took more risks than shyer ones, which did not affect survival. Bolder males but not females produced more offspring than shy conspecifics. Daily home range and core area sizes, based on 95% and 50% Kernel density estimates (20 ± 10 per individual, n = 54 individuals), were highly repeatable over time. Individual space use unfolded differently for sex‐boldness type combinations over the course of the experiment. While day ranges decreased for shy females, they increased for bold females and all males. Space use trajectories may, hence, indicate differences in coping styles when confronted with a novel social and physical environment. Thus, interindividual differences in boldness predict risk taking under near‐natural conditions and have consequences for fitness in males, which have a higher reproductive potential than females. Given extreme inter‐ and intra‐annual fluctuations in population density in the study species and its short life span, density‐dependent fluctuating selection operating differently on the sexes might maintain (co)variation in boldness, risk taking, and pace‐of‐life.

The Current State of the Vertebrate Animals Populations and their Role in the Persistence of Natural Zoonoses Foci in the Stavropol Territory

The aim of this study was to investigate the current state of vertebrates populations and to determine their role in maintaining natural foci of zoonoses in the Stavropol Territory in 2015–2019. Material and methods. Organ suspensions and blood samples from small mammals and birds were studied using certified diagnostic test-systems for the markers of Crimean hemorrhagic fever, West Nile fever, hemorrhagic fever with renal syndrome, tularemia, and leptospirosis pathogens. The data were statistically processed using Wilson’s method. Results and discussion. Identified have been the main reservoirs of natural-focal infections in the Stavropol Territory at the present stage: birds – for the West Nile fever virus, mammals and birds inhabiting the areas of semi-desert landscape-geographical zone – for Crimean hemorrhagic fever agent. The main natural reservoir of orthohantaviruses in the Stavropol Territory is the common vole Microtus arvalis, which lives in all landscape-geographical zones. The circulation of tularemia and leptospirosis pathogens has been established throughout the whole territory of the region, the small wood mouse Sylvaemus uralensis is of the greatest epizootic significance. Findings indicate the need for further epizootiologic monitoring of Stavropol Territory in order to identify the biocenotic patterns of the pathogens’ existence and the reasons that determine the dynamics of the epizootic process and epidemic manifestations of natural foci. It is advisable to determine the sites of long-term monitoring over the number of carriers and vectors of natural-focal infections and strengthen the epizootiological control over the territory, especially during periods of seasonal activity in carriers and vectors of natural focal infections.

Bark Gnawing by Rodents in Orchards during the Growing Season—Can We Detect Relation with Forest Damages?

Rodent bark gnawing is common during winter in times of low or unavailable food supply. During the growing season, it is a rare phenomenon, but can occur due to low food supply and/or poor food quality resulting from climatic influence. We evaluated this unusual damage of apple tree (Malus domestica) orchards by rodents in two localities in the Czech Republic. In 2019, 24% of trees in the orchard in Brno were gnawed by the common vole (Microtus arvalis) population. Damage in the Holovousy orchard by water vole (Arvicola amphibius) was inspected in 2020 and showed that 15% of trees were damaged with massive root gnawing. These findings were compared with gnawing in forest beech plantations in 2019, with up to 13% of trees damaged. Three rodent species (Microtus agrestis, M. arvalis and Clethrionomys glareolus) participated in the damage. Detailed description of the various vole species’ damage in vegetation period, which somehow differs from winter time damage, may help in the future in early recognition and early application of plant protection in times when this phenomenon may reappear.