FACTORS INFLUENCING MESOSTIGMATA MITES (Acari, Parasitiformes) IN THE ALKALINE FEN HABITATS

Mesostigmata mite fauna was investigated in soil of one alkaline fen at Apsuciems in the Maritime Lowland in Latvia in 2009. Thirty sample plots were selected in the following way: half of them were located in Brown Bog Rush, Schoenus ferrugineus and half — in Saw-Sedge, Cladium mariscus prevailing habitat. Soil samples were collected using a soil borer. Vegetation cover was described in accordance with Braun-Blanquet classes. Mites were extracted using modified Ber- lese funnels. In total, more than 28 species were recorded, of them Prozercon kochi and Perga- masus vagabundus were dominant species. Mean density of Mesostigmata mites ranged from 520 to 2140 ind./m^2. Mite abundance and distribution between habitats depended on vegetation cover of the vascular plants, while moss cover and soil pH had no significant influence.