British Insects: the Families of Diptera


L. Watson and M. J. Dallwitz


Adult insects. Small; slender-bodied to robustly-built. Not shining black. Not stilt-legged. The face in lateral view not deeply excavated between the antennae and the edge of the mouth. Antennae 3 segmented (the third segment short, inclined downward from the second); ‘modified’; aristate; the arista dorsal (pubescent or plumose). The second antennal segment not grooved. Ptilinal suture clearly defined. Post-vertical orbital bristles absent. 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; with a closed anal cell. The anal cell short. The costa with one break (at the end of the sub-costa). Sub-costa apparent; reaching the costa independently of vein 1. Wing vein 1 bare. Wing vein 6 present. 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; phytophagous (in stems and leaves of grasses, including cereals); acephalic. The pupae enclosed within a puparium.

Comments. Small flies with spotted or clouded wings.

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

British representation. 16 species in Britain. Genera 2; Geomyza, Opomyza.

Illustrations. • Opomyza germinationis (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.’.