Overview
Adults rest mainly on ferns, particularly in cool forests, and feed on microflora of the frond surface. The larvae of
Auster pteridii
McAlpine & de Keyzer live externally on fronds of bracken fern (
Pteridium esculentum
, family Dennstaedtiaceae) where they graze the microflora. The puparium is formed in situ without visible change in the larval cuticle.
Description
These small flies are superficially like
Drosophilla
(Drosophilidae), but more slender. Their main diagnostic features include:
Face sclerotised; only one strong orbital bristle; postocellar bristles small, ranging from convergent to slightly divergent; vibrissa present, often not set on distinct angle of face; antenna almost horizontal, with first flagellomere usually subcircular; palpus short or vestigial; prosternum reduced; tarsal claws with slash-like serrations; wing narrow, with cell cup enclosed or almost enclosed, vein A1+CuA2 long but weakly developed, and alula vestigial.
Distribution
The family lives in South America, eastern Asia, New Guinea, New Zealand and eastern and southern Australia. In the tropics, they live mainly in mountainous areas. Few of the species have yet been described. The genera
Auster
,
Lips
,
Pous
and
Teratomyza
live in Australia, the first three of these being endemic. These genera are represented in Australia by 24 species.