British Insects: the Families of Diptera


L. Watson and M. J. Dallwitz


Adult insects. Very small (about 3 mm long); winged. Antennae 2 segmented (the first hidden?), or 3 segmented (the apical segment small, squarish in profile); ‘modified’; aristate; the arista dorsal (almost bare). The arista not forked at the tip. The second antennal segment not grooved. The third segment not elongated (square-ish in profle). Ptilinal suture clearly defined. Post-vertical orbital bristles present; divergent. Mouthparts functional. The maxillary palps 1 segmented; porrect. Vibrissae present (these strong). Thorax without a continuous dorsal suture; without well defined posterior calli. Wings with a discal cell; without a sub-apical cell; with a closed anal cell. The anal cell short. The costa with one break (close to the junction where the upper margin of vein 1 merges with it); not extending around the entire wing (extending to the end of vein 3). Sub-costa apparent; joining vein 1 more or less where it joins the costa, or terminating blind (fading apically). Wing vein 4 extending far beyond the end of the first basal cell. Wing vein 6 present; falling short of the wing margin (but not by far). Wings with the lower calypter much reduced or absent. The legs with brown and yellow bands. Tibiae with a dorsal pre-apical bristle (but this short). Hind tibiae without strong bristles in the basal 4/5. Neither parasitic nor predatory (attracted to exudates from tree wounds).

Larvae and pupae. The larvae terrestrial; mycophagous (e.g., recorded from Polyporus fruiting bodies); acephalic. The pupae enclosed within a puparium.

Comments. Flies with short, thick, yellow-and-brown banded legs; with dark patches at the end of wing vein 1 and on the cross vein closing the 1st basal cell. Tibia without, or with only short dorsal preapical bristles, by contrast with Drosophilidae.

Classification. Suborder Brachycera; Division Muscomorpha Schizophora Acalyptratae; Superfamily Opomyzoidea.

British representation. 7 species in Britain. Genera 1; Odinia.

Illustrations. • Odinia.

To view the illustrations with detailed captions, go to the interactive key. This also offers full and partial descriptions, diagnostic descriptions, differences and similarities between taxa, lists of taxa exhibiting or lacking specified attributes, and distributions of character states within any set of taxa.

Cite this publication as: ‘Watson, L., and Dallwitz, M.J. 2003 onwards. British insects: the families of Diptera. Version: 1st January 2012.’.