Wingspan 25 to 46 mm. Sexually dimorphic, the females being generally much larger and plainer in appearance than the males.

Reedbeds, often coastal reedbeds.

The moths fly in July and sometimes in August, and can be attracted to light, though the males are quite sedentary.

The larvae feed internally on the stems of Common Reed (Phragmites australis) and Reed Sweet-grass (Glyceria maxima).

It is locally distributed in the southern half of England. 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).