Wingspan 24 to 40 mm. A sexually dimorphic species, with the females paler in colour and generally larger than the males. Both sexes have distinctively long labial palps.

It occupies fens and other wet places where large reedbeds occur.

Flies in June and July.

The whitish caterpillars feed inside the stems of common reed and reed sweet-grass.

Found mainly in England and Wales. In the Butterfly Conservation’s Microlepidoptera Report 2011 this species was classified as local.

Occasional in Leicestershire and Rutland. L&R Moth Group status = C (very scarce resident or rare migrant).