Wingspan 15-19 mm. (male)
Members of this family are sometimes known as 'bagworms' because of the larval habit of constructing a case, or bag, in which to live.
This species produces a long, narrow case made from fragments of sand, lichen and bark, bound together with silk, and the larva feeds on lichens where the case is attached (usually a tree trunk or fence).
The adult moths appear in May and June, and the females are completely wingless, resembling small yellow grubs. The males are dull brownish affairs.