British Insects: the Families of Diptera


L. Watson and M. J. Dallwitz


Adult insects. Very small to small; slender-bodied; stilt-legged. Antennae 8–24 segmented; ‘simple’ (long, with bead-like segments, often with whorls of hairs). Ocelli present, or absent. Eyes asymmetric, nearly or quite connected above the antennae. The maxillary palps (1–)3–5 segmented; drooping. Wing veins reaching the margin (2–)3, or 4(–6). Wings without a discal cell; without a sub-apical cell; without a closed anal cell. The costa extending around the entire wing. Sub-costa absent or only dubiously identifiable. Wings with the lower calypter much reduced or absent.

Larvae and pupae. The larvae terrestrial; phytophagous, or saprophagous, or predatory (on other insects, mostly plant bugs and immature stages of other Diptera, also mites); when phytophagous,very often forming galls (the forms of galls usually characteristic of the species), or not gall-forming; eucephalic. The pupae without a puparium.

Comments. Small to minute, delicate flies with broad and often hairy wings having greatly reduced venation, and sometimes a very short first tarsal segment. Including many gall-forming species. Females often with a very long ovipositor.

Classification. Suborder Nematocera; Division Bibionomorpha; Superfamily Sciaroidea.

British representation. 620 species in Britain. Genera about 140; with numerous species in Contarinia, Dasineura, Jaapiella, Lestodiplosis, Planetella, Rabdophaga, etc.

Illustrations. • Lestremia cinerea and L. leucophaea (Walker). • Anarete, Catocha, and Micromya (Walker). • Asphondylia, Asynapta, Cecidomyia, Rhabdophaga (Walker). • Planetella, Porricondyla (Walker). • Brachyneuria, Lasioptera (Walker). • Contarina verna (Curtis): Vernal Crane-fly (as Cecidomyia verna): B. Ent. 178. • Contarina verna (detail: B. Ent. 178). • Contarina verna (dissections: B. Ent. 178). • Contarina verna (B. Ent. 178, legend+text). • Contarina verna (B. Ent. 178, text cont.). • Lasioptera rubi: as Diomyza pulchra(?), Stephens 1846.

