BRACHYCERA, Muscomorpha Schizophora Acalyptratae, Diopsoidea

Number of British species: 26

Size: S-M

Difficulty: 2

Study group: Covered by the Stilt and Stalk fly study group

Small to medium sized (1.5-10 mm), slender to stout, yellow to reddish, brown or black coloured flies with few bristles. Head with relatively small eyes, most often with receding face; antenna small or with third antennal segment conspicuously elongate; arista short or longer pubescent; ocelli present; Ocellar bristles present; Postvertical bristles diverging or absent; 0-2 pairs of frontal bristles; scattered interfrontal setulae present; vibrissae absent. Wing usually clear to slightly tinged rarely marked, in some cases along costa, the wing tip or the crossveins with dark band(s); wing with a transverse weakening in basal half; costa with a subcostal break at some distance from where vein R₁ meets the costa; vein Sc incomplete its apical part transparent and more or less perpendicular to the basal part; crossvein BM-Cu present; cell cup closed. Tibiae without dorsal preapical bristle.

The larvae are nearly all phytophagous. They live in roots, tubers and stems of a range of non-woody herbs, a few species live under tree bark. Several species are pests in agriculture and horticulture (such as the root fly Psila rosae Fabricius, living in several crops nearly all over the world; and Psila nigricornis Meigen which inhabits the roots of chrysanthemums and other garden plants). The adults prefer a low, dense vegetation.

Collin (1944a)