Wingspan 13 to 16 mm. A rich dark brown moth with a large yellow dorsal blotch.

Where Sycamore is present.

On the wing from May to July. The adults fly from late afternoon into the night, and can be attracted to light.

The larvae feed inside the seeds of Sycamore, and pupate in a crevice of the bark. Newly hatched moths can sometimes be found resting on the bark before they move higher into the canopy.

Fairly common over most of Britain. In the Butterfly Conservation's Microlepidoptera Report 2011 this species was classified as common.

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