Scarce Umber Moth (Agriopis aurantiaria)
It is not difficult to name this moth from just a few pictures. Only very unmarked Mottled Umbers are similar. But they never have the same, warm golden yellow basic colour of the Scarce Umber Moth. Besides: the number of Mottled Umbers on the wing usually is quite low when the Scarce Umber Moth is flying about, for it usually flies earlier. The Scarce Umber Moth is not very variable. All this applies to the males, because the females have very reduced wings and can not fly. These reduced wings make them standing out from most other wingless geometers. The males reach a wingspan of 40 to 44 mm.
The eggs are being laid in autumn, but don't hatch before April next year. Young caterpillars of the Scarce Umber Moth are almost identical to young larvae of the Dotted Border. They are hard to spot greenish caterpillars with some white, greenish, yellowish or greyish lines. The young caterpillars are hard to identify. Older ones show more markings and present you with less problems. The caterpillars reach a length of some 3 cm and are found on numerous broad leaved trees and shrubs, such as Birch and Hazel.
Adults are on the wing October - December, but usually getting scarcer after some frost. The Scarce Umber Moth flies by night only. It is however easily attracted to light. Rests during the day, sometimes very visibly on a fence or wall. A common, but often very local species, but regularly very abundant, throughout Southern Britain, scarcer northwards, but present as north as Orkney. Also a widespread but local species in Ireland and on the continent.
The caterpillar in the pictures could be the Dotted Border's. At this stage it is extremely hard to tell them apart!