Ulidiidae Macquart, 1835

Small to large (2.5-11.0 mm), moderately robust flies, variable in colour, from partly yellow to black, sometimes grey microtomentose or shining metallic. Head shape variable, arista bare to long haired. Ocelli present, ocellars developed, postvertical (postocellar) setae parallel or divergent, 1-2 fronto-orbital setae and scattered interfrontal setulae present, vibrissae absent; however, in some species all cephalic setae may be reduced or absent. Tibiae usually without dorsopreapical setae. Wing mostly dark banded or maculated, or darkened at tip, rarely clear or unicolourous. Costa often continuous or with only a humeral break; subcosta complete; R1 setulose or bare, cells bm and cup present, the latter often cuspidate. Distiphallus very long, spirally coiled, bare or spinulose. Female postabdomen with 7th segment modified into a sclerotized oviscape; 8th tergosternite forming the basal part of aculeus and flexibly jointed to the cap-like cercal unit. The larvae are mostly saprophagous and develop in rotting matter, under bark or in dung; some apparently are phytophagous. The adults live in marshland habitats, woodland areas, sandy, salty or steppe meadows, and often occur on the leaves of shrubs, tree trunks, on flowers, and also on excrement and manure heaps.

Following Kameneva and Korneyev (1994, 2006), the current concept of the Ulidiidae also includes the subfamily Otitinae, which has often been treated as a separate family in the past, most recently by e.g. Greve (1998). In the PCV2, the Otitidae and Ulidiidae were listed separately (Martinek 1997, Zuska 1997); since ECV1 they are combined, following the Fauna Europaea (Kameneva & Greve 2007). Altogether 105 species are known from Europe (Kameneva & Greve 2007) and 36 are listed in the present checklist: 27 in the Czech Republic (22 in Bohemia, 26 in Moravia) and 36 in Slovakia. Since the ECV1, the number of species in the Czech Republic has not been changed but five species have been added for Slovakia. Kameneva and Korneyev (1994, 2006) diagnosed the family; but there is no contemporary treatment of the whole European fauna nor any comprehensive study of the Czech or Slovak species. However, the latter are relatively well known thanks to the many papers by Martinek (for references, see Barták (2001) and Martinek and Barták (2001)), Kameneva (2008) and Roháček and Heřman (2009). The Central European species can be identified using the keys by Soós (1980), Richter (1970a, b), Clements (1990), Andersson (1991), Merz (1996a, b) and Kameneva (1996, 2008), supplemented by Carles-Tolrá (1998). The nomenclature used here follows that in the Fauna Europaea (Kameneva & Greve 2007).