The mild mid-winter weather has been good for Winter moths. The Devon lanes around Buckfastleigh have been alive with the pale fluttering males caught in the headlights just after dusk and I have seen several bats which have remained active to cash in on this feast. The flightless females are more difficult to find as they crawl up the trees and hedges to mate and lay their eggs.
Only 14 species of the British ‘macro’ moths have flightless females and all but two of these are ‘geometers’ which fly between November and March. Only the March Moth and Pale Brindled Beauty have completely wingless females. The others including the Winter moth have very short wings which are useless for flight. This has probably evolved so the female moths do not waste resources and energy on flight in the cold conditions.
The males are said to occasionally carry females in flight during mating though I have not managed to observe this yet. They are still not likely to fly far and it is the larvae which are able to disperse. The blue-green eggs are laid in crevices on bark. The newly emerged larva is able to produce a thread of silk which catches the wind and enables it to move around. The larvae feed on a wide variety of trees and shrubs so shouldn’t have difficulty finding food wherever they settle.