Length 18 to 28 mm. The female is the largest British caddisfly and has a dark stripe on the forewing which is not present in the male. The male is also the smaller of the sexes.

Around still and slow moving water. It is sometimes attracted to light.

May to August with a peak in early July.

Breeds in still and slow moving water including large lowland rivers and canals with plenty of submerged vegetation. The larval case in constructed from spirally arranged plant fragments.

Widespread and fairly frequent in much of England, but fewer records from Scotland and Wales. 

Status in Leicestershire and Rutland not known.