Orange Underwing Archiearis parthenias
Wingspan 30-40 mm.
This is a day-flying moth, unusually being on the wing in the early part of the year between March and April, preferring to fly in sunshine.
It inhabits birch woods, in England, Wales and parts of Scotland.
The greenish caterpillar feeds firstly on the catkins, and then on the leaves of birch (Betula)..