An unusual diversity of Ulidiidae (Diptera) in a rich fen in Central Bohemia (Czech Republic)

Species of Ulidiidae (Diptera) have been studied in the Hrabanovská černava reserve, a well-preserved calcareous lowland rich fen situated in the Polabská nížina (Elbe river basin) near Lysá nad Labem, in Central Bohemia (Czech Republic). A total of 9 species have been recorded, including two representing the first records from the Czech Republic: Herina oscillans (Meigen, 1826) and Euxesta notata (Wiedemann, 1830), the latter being a recent invader from North America. Herina scutellaris Robineau-Desvoidy, 1830 has been confirmed in the Czech Republic and recorded from the northernmost known locality. The latter species, and particularly H. oscillans, are considered the most significant elements of this fen type. Due to their unique occurrence and association with a highly endangered biotope, it is proposed to consider them as endangered (EN) species in the Czech Republic. A second record of Homalocephala biumbrata (Wahlberg, 1839) from Bohemia is presented. The species richness of Ulidiidae in the fen under study and habitat association of all recorded species are discussed.