Unlike most other moths, males of Orgyia antiqua fly during the day (often relatively highly) and are sometimes mistaken for butterflies (Waring and Townsend, 2006). The females are also unusual because they have no wings and remain on the cocoon from which they hatch. Eggs are laid on the cocoon, overwinter, and hatch from May onwards.

Orgyia antiqua life stages: eggs (left), caterpillar (middle) and copulating adults © Tristan Bantock (right). See below for Flickr links to larger images.

After reading about the moth and looking its life stages, I remembered/realised that our apple tree gets eaten by them every year! I will look for the adults this year, which should be easier now that I know what I’m looking for.

Flickr links: Eggs, caterpillar and adults © Tristan Bantock

Reference:
Waring, P. and Townsend, M. (2006) Field Guide to the Moths of Great Britain and Ireland. Dorset, British Wildlife Publishing