Willow Ermine Yponomeuta rorrella
Wingspan c. 20mm.
A relatively local species, occurring sporadically in much of England, though with an eastern and coastal bias.
As suggested by the vernacular name, the larvae feed on species of willow, especially white willow (Salix alba) and grey willow (S. cinerea). They feed gregariously on the leaves in a silken web, between May and July.
The adult moths fly in July and August, and in common with others in the group, are readily attracted to light.