Wingspan 18 to 22 mm. This species is easily recognisable by the moon-shaped creamy-white marking at the cleft in the brownish forewing.

It prefers dry habitats, such as downland, shingle beaches and sand-dunes.

It flies from dusk onwards in late June and July.

The larvae feed on rest-harrow.

It is locally distributed in the south of England and Wales in suitable habitat. In the Butterfly Conservation's Microlepidoptera Report 2011 this species was classified as local.

It appears to be uncommon in Leicestershire and Rutland, where there are few records. L&R Moth Group status = D (rare or rarely recorded).