Overview
Adults have often been found on low herbage and foliage of broad-leaved plants, particularly at forest margins. Larvae of some asteiids live in fungi or rotting plant material, but larvae have not been recorded in Australia.
Description
Asteiids are small, usually rather slender, long-winged flies. They are recognised by the following features:
Postvertical bristles divergent or absent; orbital bristles usually only one or absent; vibrissa may be either present or absent; face sclerotised; arista of antenna variable and sometimes absent; presutural and anepisternal bristles absent; katepsiternal bristles usually present; propleuron without vertical carina (compare Chloropidae); prosternum broad, without precoxal bridge; legs without strong bristles; wing with vein C unbroken; Sc incomplete distally; vein R2+3 often short and distally joined to R1 or to C shortly beyond the apex of R1 (long in Leiomyza); veins R4+5 and M distally convergent; vein M without trace of angle or flexure where it meets crossvein dm-cu, or dm-cu absent; crossvein bm-cu absent; cell cup and vein A1+CuA2 absent.
Distribution
Asteiids have a worldwide distribution, with six species living in Australia. Though generally uncommon, they are sometimes locally numerous.