Wingspan 19 to 22 mm.  A distinctive species with its very dark forewings and broad white cross-line.G

In view of the scarcity of this species in VC55 any records should be supported by photographs.

It inhabits old, mature woodland and parkland, and spends much of its life high up in large oak trees.

The flight period is from June to July. 

Oak is the larval foodplant.

A scarce resident, occurring mainly in the south of England. In the Butterfly Conservation's Microlepidoptera Report 2011 this species was classified as Nationally Scarce B.

Rare in Leicestershire and Rutland. A record from Ketton Quarry on 29 June 2019 was the first for VC55.