British Insects: the Families of Diptera


L. Watson and M. J. Dallwitz


Adult insects. Small. Not shining black. Not stilt-legged. The face in lateral view not deeply excavated between the antennae and the edge of the mouth. Antennae 2 segmented (or the basal segment concealed), or 3 segmented (very short); ‘modified’ (very short); aristate; the arista dorsal. The arista not forked at the tip. The second antennal segment not grooved. Ptilinal suture clearly defined. Eyes rounded, well separated. Post-vertical orbital bristles present; convergent (crossed). Mouthparts functional. The maxillary palps 1 segmented; porrect. Vibrissae absent. Thorax without a continuous dorsal suture; without well defined posterior calli. Wing venation complete, in the sense of exhibiting 1st and 2nd basal, anal and discal cells. Wings with a discal cell; without a sub-apical cell; with a closed anal cell. The anal cell short. The costa with one break (near the end of vein 1), or unbroken. Sub-costa apparent; reaching the costa independently of vein 1 (but faint). Wings without a ‘vena spuria’. Wing vein 1 bare. Wing vein 6 present; reaching the wing margin (faint), or falling short of the wing margin. Wings with the lower calypter much reduced or absent. Tibiae without a dorsal pre-apical bristle. Hind tibiae without strong bristles in the basal 4/5.

Larvae and pupae. The larvae terrestrial; coprophagous (in guano); acephalic. The pupae enclosed within a puparium.

Comments. Small yellowish flies with very short antennae.

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

British representation. 8 species in Britain. Genera 3; Aphaniosoma, Chyromya, Gymnochiromyia.

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.’.