British Insects: the Families of Diptera


L. Watson and M. J. Dallwitz


Adult insects. Very small (mostly under 3 mm long); slender-bodied. The face in lateral view not deeply excavated between the antennae and the edge of the mouth. Antennae 3 segmented (the third segment inclined down from the second); ‘modified’; aristate; the arista dorsal (pubescent or shortly plumose). The second antennal segment not grooved. The third segment not elongated (short and rounded, thickly pubescent and inclined downwards from the second). Ptilinal suture clearly defined. Lower orbital bristles present (one, small and never incurved), or absent. Post-vertical orbital bristles present (very small), or absent; when present, convergent to divergent. Mouthparts functional. The maxillary palps 1 segmented; porrect. Vibrissae present. Thorax without a continuous dorsal suture; without well defined posterior calli. Wings with a discal cell; with a closed anal cell. The anal cell short. The costa unbroken (but then sometimes distictly narrowed near the end of vein 1), or with one break (close to where the upper margin of vein 1 merges with it). Sub-costa apparent; joining vein 1 well short of the costa, or terminating blind. Wing vein 6 present; falling short of the wing margin. Wings with the lower calypter much reduced or absent. The front femora with a short stout spine beneath which is readily distinguishable from the other bristles. Tibiae without a dorsal pre-apical bristle. Hind tibiae without strong bristles in the basal 4/5. Feet without a triple pad.

Larvae and pupae. The larvae terrestrial; phytophagous (mining stems or leaves of grasses and rushes); acephalic. The pupae enclosed within a puparium.

Comments. Small or very small, slender bodied flies with long narrow wings. The underside of the front femora with a short stout spine which is conspicuous among the other bristles..

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

British representation. 19 species in Britain. Genera 6; Anagnota, Anthomyza, Cercagnota, Paranthomyza, Stiphrosoma, Typhamyza.

Illustrations. • Anthomyza albimana: B. Ent.721. • Anthomyza albimana: B. Ent.721, legend+text. • Anthomyza albimana: B. Ent.721, text cont.. • Anthomyza albimana (from Walker).

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.’.