Acalyptrate flies (Diptera) on glacial sand deposits in the Hlučínsko region (NE Czech Republic): most interesting records

Records of six species of the families Ulidiidae, Anthomyzidae, Asteiidae, Milichiidae, Chloropidae and Curtonotidae from glacial sand deposits in the Hlučínsko region (NW Czech Republic) are presented and their association with sandy habitats are discussed. Two thermophilous and/or xerophilous species, Anthomyza elbergi Andersson, 1976 (Anthomyzidae) and Desmometopa discipalpis Papp, 1993 (Milichiidae) represent new additions to the fauna of the Czech Republic. Two psammophilous or psammobiont species, Eutropha variegata Loew, 1866 (Chloropidae) and Curtonotum anus (Meigen, 1830) (Curtonotidae) are recorded for the first time from Moravia and the Czech Silesia respectively, the latter from a locality lying on northern border of its distributional range. Also Asteia elegantula Zetterstedt, 1847 (Asteiidae) is first recorded from the Czech Silesia and Desmometopa discipalpis is recorded from its northernmost known locality. Information on microhabitats of these species and also the psammobiont Tetanops myopina Fallén, 1820 (Ulidiidae) in sandpits are provided and most of them were photographed alive. The origins of populations of these species on glacial sands in the Hlučínsko region are discussed and it is concluded that while Asteia elegantula and Eutropha variegata are widespread in the W Palaearctic, Curtonotum anus and Desmometopa discipalpis are distinctly of southern origin and, most interestingly, Tetanops myopina and Anthomyza elbergi seem to originate from northern Europe and may have reached this area already during the Saalian glaciation (cca 160 000 ya).