BRACHYCERA, Asilomorpha, Empidoidea
Number of British species: 2
Scheme: Covered by the Empids and Dollies recording scheme
Minute to small (1.5-2.75 mm), black flies. Head rather small; eyes big, holoptic in male; third antennal segment with an arista of 1-3 times its own length; mouthparts relatively short, directed forward or somewhat down. Wing clear or tinged, with a stigma spot between apex of veins Sc and R1, stigma spot sometimes indistinct; cell dm absent and vein M not forked; cell cup normally larger than cells br and bm, if not then CuA2 convex and anal vein arched to wing margin; alula and large anal lobe usually present. Tibia of hind leg, and in some cases first tarsal segment as well, sometimes dilated and laterally compressed.
The biology of this small family is little known. The larvae are unknown. Adults of Atelestus mainly occur in grassland or patches of herbs or on leaves in deciduous woodlands, often near water. Both sexes fly in swarms. Because of the anatomy of their mouthparts, the adults are presumed to be flower visitors.