Mycetophilidae Newman, 1834

Small to relatively large (2.0-15.0 mm), morphologically diverse, yellowish to dark brown fungus gnats. Head with two or three ocelli; antenna with scape and pedicel short, flagellum with 14 segments, varying from short to long. Thorax hump-backed, coxae long, legs strong or narrow, typically with numerous bristles, abdomen usually narrow. Wings often with dark markings, wing membrane with or without macrotrichia. Sc ending in C, free or R, vein M-Cu close to wing base. The larvae are mycophagous, feeding on the mycelia or fruit bodies of various fungi or myxomycetes. The adults are common in the undergrowth of forests, especially in shaded places alongside streams, in cavities under tree roots and overhanging stream banks, but also in other habitats such as meadows and steppe habitats.

The Mycetophilidae is a species-rich family with about 950 species in Europe (Chandler 2007) and more than 3500 described species in the world (Søli et al. 2000), but at least the same number of species still await description. Altogether 603 species are listed in the present checklist: 542 from the Czech Republic (391 in Bohemia, 476 in Moravia), and 445 from Slovakia. Since the PCV2 (Košel et al. 1997), the number of species has almost doubled due to intensive research during the past decade (for details see comments and links in species table); 186 species have been added to the Czech Republic (159 to Bohemia and 178 to Moravia) and 172 species to the fauna of Slovakia. Since the ECV1 (Ševčík & Košel 2006), 11 species have been added to the Czech Republic (58 to Bohemia and 4 to Moravia), and 52 species to Slovakia (Papp & Ševčík 2007, Rulik & Heller 2007, Ševčík 2006e, 2007, 2009a, b, Ševčík & Chandler 2008).  The species composition of Mycetophilidae in both the Czech Republic and Slovakia is thus now better known, but many additional species are expected to occur and several taxonomic problems still remain to be solved. Unreliable records (identifications of females or those based on old literature, see e.g. Straka & Majzlan 2006) are not included in this checklist until they are not confirmed by specialists.

The basic characteristics and a comprehensive morphological review of the family were recently given by Søli (1997) and Søli et al. (2000), including a modern key to the European genera. The identification of the European species is possible using numerous papers, including the handbooks by Hutson et al. (1980), Søli et al. (2000) and Zaitzev (1994, 2003). The nomenclature used in the present checklist mainly follows that in the Fauna Europaea (Chandler 2007), but the phylogeny and systematics within the family are still not fully clarified.