There are some differences between males and females; males tend to be smaller and darker overall with predominantly orange-brown hindwings, whereas the females are brownish white. The males have feathery antennae.
The males are stronger fliers often active in sunshine and overcast conditions from mid-morning to early afternoon. Females fly at dusk but have been found resting on twigs of birch. The caterpillars can be found from mid-May to mid-August before overinwintering as pupae in a webbed cocoon on the ground.
Size and Family
- Family – Endromidae
- Large Sized
- Wingspan range – 54-78mm
- UK BAP: Not listed
- Scarce (Nationally Scarce A)
Caterpillar Food Plants
Silver Birch (Betula pendula) and sometimes Downy Birch (Betula pubescens) and Alder (Alnus glutinosa).
Prefers open birch woodland and lightly wooded moorland.
- Countries – Scotland
- This species used to be more widespread occurring in some southern counties, including Kent, Sussex, Berkshire, East Anglia, Herefordshire, Worcestershire and Monmouthsire, but it is now restricted to suitable habitat in the central and eastern Highlands of Scotland, and is known from Perthshire, Inverness-shire, Morayshire, Aberdeenshire and Kincardineshire.