Drosophilidae Rondani, 1856

The Drosophilidae are small flies (mostly 2.0-4.0 mm long, exceptionally up to 7.0 mm), predominantly yellowish-brown to dull black. Two costal breaks always present. Most species may be recognized from their conspicuously plumose arista, with both dorsal and ventral rays (unlike many Ephydridae, which have only dorsal rays, if any); in three European genera the arista is only micropubescent, and  these are characterized by interfrontal and anepisternal setae absent, postocellar setae divergent, subcosta apically vestigial or confluent with R1, and anal vein well developed. The biology of the family is very diverse (Ashburner et al. 2005). Most species of the subfamily Drosophilinae concentrate around fermenting plant substrates, Lordiphosa and Scaptomyza species are common in the herb layer. Asynanthropic species occur in all terrestrial habitats, from lowlands up to alpine meadows. Some of the synanthropic species are artificially reared and are extremely important laboratory animals. Various members of the subfamily Steganinae occur near the habitats of their insect hosts or prey (mealybugs, bees, wood-boring beetles), whilst some are found around toadstools (Polyporales) and in the flower heads of thistles. Phortica variegata (Fallén, 1823) is a vector of the nematode Thelazia callipaeda. The drosophilid larvae are elongate, and have anterior spiracles with long branches that are specifically characteristic in number and shape. The puparia have a dorsoventrally compressed anterior end, and hind spiracles widely separated (Steganinae) or on closely apposed processes (Drosophilinae). The larvae of most species develop in fermenting substrates, which are often different from the substrates most frequented by the adults (Ferrar 1987, Gornostaev & Markov 1995); they feed mainly on microorganisms. Some Drosophilinae mine in living plants, and at least some Steganinae have carnivorous larvae.

More than 4000 species of Drosophilidae have been described (Bächli 2006). Only 121 species, including recent immigrants, occur in Europe and adjacent islands including the Macaronesian subregion (Bächli et al. 2004). Since the ECV1 (Máca 2006) the species number remained unchanged in the Czech Republic (but increased by one in Moravia) and it has increased by two in Slovakia. In the present checklist version,  77 species are listed: 75 from the Czech Republic (71 from Bohemia, 68 from Moravia) and 70 from Slovakia. The fauna of Drosophilidae is relatively well known in both the Czech Republic and Slovakia (Bächli 1988, Máca 1997, 1999, 2004, Máca & Barták 2001, Papp 2000, Máca et al. 2005).  For that reason, the abovementioned numbers have not been recently substantially changed.

A monograph of this family, dealing with most European species and relevant for the study of the species in the Czech Republic, has been published by Bächli et al. (2004). Useful information on Drosophilidae from the Czech Republic and Slovakia can be also found in monographs dealing with individual genera or in primarily faunistic papers, as reviewed by Máca and Barták (2001).