Infestation and Seasonal Fluctuation of Gamasid Mites (Parasitiformes: Gamasida) on Indochinese Forest Rat, Rattus andamanensis (Rodentia: Muridae) in Southern Yunnan of China

A 12-month consecutive investigation was made at Jingha village in southern Yunnan of southwest China from April 2016 to March 2017. A total of 2053 Indochinese forest rats (Rattus andamanensis Blyth, 1860) were captured and examined, which account for 84.69% (2053/2424) of all the animal hosts (rodents and other small mammals) at the investigation site. And 39.82% (13,531/33,980) of gamasid mites were identified from the body surface of R. andamanensis and they belong to 41 species, 10 genera, 3 subfamilies and 2 families. Of the 41 species of gamasid mites identified from R. andamanensis, Laelaps nuttalli Hirst, 1915 and Laelaps echidninus Berlese, 1887 were the most dominant with 70.63% and 20.67% of constituent ratios respectively. In monthly fluctuations of all the gamasid mites on R. andamanensis, the constituent ratio (Cr) and overall infestation mean abundance (MA) of the mites in 12 months showed two obvious peaks in January (winter season) and June (summer season). However, the two dominant mite species, L. nuttalli and L. echidninus, showed different patterns of seasonal fluctuations. Laelaps nuttalli occurred throughout the year, and its Cr and MA showed two prominent peaks in winter season (December and January) and summer season (June), which belongs to the summer-winter type of seasonal fluctuation. Laelaps echidninus also occurred on R. andamanensis throughout the year, but its Cr and MA showed only one peak in winter season (December and January), which belongs to the winter type of seasonal fluctuation. A negative correlation existed between two climatic factors (temperature and rainfall) and the infestations (Cr, prevalence PM and MA) of two dominant mite species (L. nuttalli and L. echidninus) on R. andamanensis (p < 0.05). Temperature and rainfall are considered to be two key factors that influence the seasonal fluctuations of the mites on the studied rat species.

Ectoparasite Complex of the East European Vole Microtus rossiaemeridionalis (Arvicolinae, Rodentia) on the Northern Border of the Range in Western Siberia

The purpose of the research is establishing the composition, infection rates, species and group ratio of ectoparasites of the East European vole on the northern border of the range in Western Siberia (Middle Ob Region). Materials and methods. In 2015–2018, in order to capture the provider of ectoparasites, the East European vole, we used methods of trap lines, trap trenches, and fence-traps; we recorded 173 animals from which we collected 881 specimens of gamasid mites, ixodic ticks, lice and fleas. To assess the quantitative indicators of ectoparasites, the indices generally accepted in parasitology were used. Results and discussion. In 2014, it was established for the first time that there is a sibling species of the common vole, the East European vole in the Middle Ob Region (middle taiga of the forest zone of Western Siberia). In the city of Surgut and its neighborhood, this animal is confined to the most transformed biotopes. The ectoparasite complex of the East European vole includes 26 species of parasitic arthropods. By the number of species (13) and individuals, gamasid mites predominate, and the proportion of ixodic ticks, lice and fleas put together is almost 3 times lower. In a climate of the Middle Ob Region, the list of ectoparasites will no doubt grow as the range of habitats expands and the contacts of the East European vole with other small mammals increase, and its role in maintaining pathogen circulation of natural focal infectious diseases will increase.

An annotated catalogue of the gamasid mites associated with small mammals in Asiatic Russia. The family Hirstionyssidae (Acari: Mesostigmata: Gamasina)

This article represents the third (and last) part of the catalogue of ectoparasitic gamasid mites associated with small mammals in Asiatic Russia (Siberia and the Russian Far East). A total of 19 species of the genus Hirstionyssus Fonseca, 1948 are indexed, with data on their taxonomic position, nomenclature, host range, and distribution within the region. As a conclusion, a brief overview of fauna of ectoparasitic gamasid mites parasitising Micromammalia (except bats) of Asiatic Russia is given. In total, 71 mite species belonging to nine genera of three families (Haemogamasidae, Hirstionyssidae, Laelapidae) are recorded and divided among taxonomic and ecological groupings.

Ectoparasites of a steppe lemming Lagurus lagurus Pallas, 1773 in the South Transural region (Kurgan oblast) in connection with the natural foci of tularemia

Steppe lemming of the South Trans-Ural region is a rare species of open spaces. To the north, its distribution is limited to the subzone of herbbunchgrass steppes and the southern strip of the forest-steppe subzone. The presented work summarizes the material, which gives the full species composition of the parasitic arthropods of this rodent, and gives quantitative characteristics of ectoparasites. In total 155 individuals and one nest of steppe lemming were examined for ectoparasites. There are 808 parasitic arthropods of 20 species, including 14 species of gamasid mites, 2 species of ixodid ticks and 4 species (subspecies) of fleas. According to the number of individuals of ectoparasites feeding on the steppe lemming, the dominance of gamasid mites is strongly pronounced, both prevailing multi-host species and specific, typical for other rodents (gray and red-backed voles, northern mole vole, Eurasian water vole, northern birch mouse). The contribution of ixodid ticks and fleas to the parasitofauna of the steppe lemming is small. Steppe lemming can be involved in circulation of a causative agent of tularemia in the South Trans-Ural region, but as an additional carrier in maintenance of a foci in biotopes, where it contacts the habitats of the Eurasian water vole.