Geographical Differentiation of Mites from the Suborder Uropodina (Acari: Mesostigmata) in Dead Wood in Europe in the Light of Recent Research

Dead wood is an important microhabitat for Uropodina mites (Acari: Mesostigmata). Earlier research has shown that dead wood contains about 1/3 of the Uropodina found so far in Poland, and its presence increases the overall biodiversity of forest ecosystems by 40%. The major aim of the current study is to assess the geographical variation of species diversity of Uropodina inhabiting dead wood in Poland and other European countries. The samples from dead wood (1180 samples in total) were collected in seven provinces in Poland, and in eight other countries (France, Italy, Belgium, The Netherlands, Slovakia, Sweden, Norway, and Denmark). Fifty-two Uropodina species were recovered from dead wood in seven provinces in Poland. The highest number of species was recorded in dead wood samples collected in Wielkopolskie, and the lowest in those from Zachodniopomorskie. The total number of species in the examined dead wood in the surveyed European countries was 24 species, ranging from 4 to 13 species per country. The most common species in the examined material from both Poland and other studied European countries were Oodinychus ovalis (C.L. Koch, 1839) and Pulchellaobovella pulchella (Berlese, 1904), though the frequency of the other species found in those areas was low. The differences in species diversity of the examined fauna of Uropodina probably result in the difference in the extent of the research carried out so far in some regions of Poland, lack of sufficient data for other European countries, as well as the highly diversified geographical ranges of most Uropodina species. The obtained results clearly show that there is still a need for further, more extensive research, based on a larger number of samples from dead wood from the whole continent