Wingspan 30 to 40 mm.

Hedgerows where Hawthorn or Blackthorn are present.

The adults fly in February and March, but are seldom seen.

Larvae live gregariously in silken webs on the foodplants Hawthorn or Blackthorn. Larval records are perhaps more likely than adults to light; all records of larval webs are welcomed, but will be marked as sensitive and not be mapped.

Formerly quite common, this is now a scarce and local species. It is now restricted to a few scattered colonies in England and Ireland, and a few localities in Wales. In a recent survey to determine the status of all macro moths in Britain this species was classified as Nationally Scarce B.

Rare in Leicestershire and Rutland. The Morcott record of 3rd April 2018 is the first in VC55 for many years.