Dixidae Schiner, 1868

Jan Ševčík¹, Jozef Halgoš²

¹Silesian Museum, Tyršova 1, CZ-746 01 Opava, Czech Republic; sevcikjan@email.cz

²Department of Zoology, Komenský University, Mlynská dolina, SK-842 15 Bratislava, Slovakia; halgos@fns.uniba.sk

Medium-sized (4.0-8.0 mm), yellowish to dark brown midges. Head with dichoptic eyes, without ocelli; antenna elongated with scape and pedicel short, flagellum with 14 segments. Mouthparts non-functional. Thorax hump-backed, mesonotum usually with dark longitudinal stripes, coxae relatively short, legs long and narrow, abdomen elongated and narrow. Wings hyaline, in species of Dixa Meigen, 1818 with dark markings, wing membrane without macrotrichia or scales. The larvae are aquatic, eucephalic, with several distinctive features (crowns, combs, terminal complex) that are widely used for the identification of species groups; they rest in a characteristic U-shaped position at the water meniscus. The larvae of Dixa prefer running waters, while those of Dixella Dyar & Shannon, 1924 live in stagnant waters. The adults are poor fliers and can be found near the larval habitat.

There are some 400 described species in the world (Wagner 1997, 2004) and about 30 species in Europe (Wagner 2004). Altogether 12 species are listed in the present checklist (10 from the Czech Republic, 9 in Bohemia, 10 in Moravia, and 10 from Slovakia). Since the last version of the checklist (Knoz 1997), no species have been added to the Czech Republic, but 3 species has been added for Bohemia and 1 for Moravia; and 5 species have been added to the fauna of Slovakia (Bitušík 1995, Bulánková & Halgoš 1999, Halgoš & Bulánková 2003, Martinovský 1998, Martinovský & Barták 2000, Ševčík 2006). The species composition of the Dixidae in both the Czech Republic and Slovakia is still inadequately known, because no specific faunistic research has yet been carried out. Most of the records from Slovakia should be verified, because they are based only on the identification of the larvae.

The basic characteristics of the family were recently given by Disney (1999) and Wagner (1997), including keys to both the larvae and adults of most European species. The nomenclature in the present checklist follows that in the Fauna Europaea (Wagner 2004).

References

[1] Bitušík P. 1995: Výsledky prieskumu niektorých vodných biotopov v CHKO Kysuce. In Korňan J. (ed.): XXVI. Stredoslovenský tábor ochrancov prírody Kysuce. Slovenský zvaz ochrancov prírody a krajiny, Spišská Nová Ves, pp. 21-30.

[2] Bulánková E. & Halgoš J. 1999: New data on the distribution of Dixidae (Diptera) in Slovakia. In Jedlička L. (ed.): Dipterologica Bohemoslovaca, Vol.  9. Slovak Entomological Society, Bratislava, pp. 25-29.

[3] Halgoš J. & Bulánková E. 2003: First record of the species of the genus Dixella Dyar & Shannon, 1924 (Dixidae, Diptera) from Slovakia. Biologia, Bratislava 58: 178.

[4] Disney R.H.L. 1999: British Dixidae (meniscus midges) and Thaumaleidae (trickle midges): keys with ecological notes. Freshwater Biological Association Scientific Publication No. 56. 129 pp.

[5] Knoz J. 1997: Dixidae.  In Chvála M. (ed.): Check List of Diptera (Insecta) of the Czech and Slovak Republics. Karolinum – Charles University Press, Prague, p. 33.

[6] Martinovský J. 1998: Dixidae. In Rozkošný R. & Vaňhara J. (eds): Diptera of the Pálava Biosphere Reserve of UNESCO I. Folia Facultatis Scientiarum Naturalium Universitatis Masarykianae Brunensis, Biologia 99: 91-92.

[7] Martinovský J. & Barták M. 2000: Dixidae. In Barták M. & Vaňhara J. (eds): Diptera in an Industrially Affected Region (North-Western Bohemia, Bílina and Duchcov Environs), I. Folia Facultatis Scientiarum Naturalium Universitatis Masarykianae Brunensis, Biologia 104: 113-114.

[8] Ševčík J. 2006: Faunistic records from the Czech and Slovak Republics: Ditomyiidae, Keroplatidae, Mycetophilidae, Dixidae. Entomofauna carpathica 18: 46.

[9] Wagner R. 1997: Family Dixidae. In Papp L. & Darvas B. (eds): Contributions to a Manual of Palaearctic Diptera. Vol. 2. Nematocera and Lower Brachycera. Science Herald, Budapest, pp. 299-303.

[10] Wagner R. 2004: Fauna Europaea: Dixidae. In Jong H. de (ed.): Fauna Europaea: Diptera, Nematocera. Fauna Europaea version 1.1, http://www.faunaeur.org.