Taken a month ago on our Red Campion
Wingspan 25-35 mm.
The adults of this species are relatively dull in coloration, but the caterpillars are much more colourful, with orange, white and blue stripes on a dark brown ground colour.
The larvae feed gregariously in a web of silk, on hawthorn (Crataegus), blackthorn (Prunus spinosa) and other trees and shrubs.
Occurring mainly in the southern half of Britain, the flight period is July to August.
Moth Photo and info from UK moths