The fauna of free-living gamasid mites (Parasitiformes, Mesostigmata) in the northern Taiga: an analysis of the zonal specificity

Abstract

According to the data of four-year sampling, the territory of the Pinega Reserve (Arkhangelsk Province) is populated by more than 117 gamasid mite species belonging to 18 families. A relative richness of this fauna is obviously associated with intensive karst processes. A number of species (arctic, Siberian, mountainous) is limited to karst localities characterized by low soil temperature and a short vegetation period. When comparing the local Mesostigmata faunas from different regions, it was suggested that only species lists of unspecialized free-leaving forms should be used. Changes in the species richness of separate families and their fraction in the total suborder diversity along the latitudinal gradient from dry steppes to polar deserts are individual, reflecting different ecological potencies. The zone of deciduous forests is characterized by the richest fauna of Mesostigmata as a whole and of the majority of its families. The northern boundaries for the distribution of separate families are outlined. The number of free-leaving species in the families Ascidae, Phytoseiidae, and Zerconidae varies most smoothly along the latitudinal gradient. Even in polar deserts, Ascidae and Phytoseiidae are represented by more than a single species. It is in the taiga that the family Ascidae becomes the most diverse among Mesostigmata. In the tundra zone, this tendency is more pronounced, and in polar deserts this family constitutes 70–83% of species in local faunas, represented mainly by the genus Arctoseius.