Wingspan male 48 to 53 mm, female 59 to 65 mm. The male has prominent crescent-shaped black reniform mark and black orbicular spot.  The whitish, cumbersome females are much larger than the males, and cannot fly well.

Good quality photograph required.

Well wooded areas.

Adult: July and August.

The larval foodplants are a range of deciduous trees and in continental Europe the species is a common pest.

In the early part of the 19th century, this was a common species in the East Anglian and southern fens, but by about 1900 had become extinct as a breeding species. Since 1995 the species has been resident in small numbers in parts of London and may now be spreading in England. In a recent survey to determine the status of all macro moths in Britain this species was classified as Vagrant/Accidental.

Rare in Leicestershire and Rutland. A record from Woodhouse Eves on 22 Aug 2017 was the first for over 100 years in VC55.