Winter moth

At this time of year it can be quite hard to find insects out in the cold weather; however, winter is the peak time of activity for some species. As its name suggests, the Winter moth is a hardy winter loving species which can be seen flying from late autumn through to late January or February. This moth can often be seen in the glare of car head lights when driving past woodland or hedgerows.

Fast Facts

Latin name: Operophtera brumata

Notable feature: Males have pale brown wings with dark cross bands

Rarity in the UK: Rare / Common

Where in the UK: Widespread throughout most of Britain

Males and Females

Male and female Winter moths are quite different in appearance. Male Winter moths have dark cross bands on their wings whereas females are totally flightless with tiny dark-striped wings allowing them to be easily distinguished from each other. Both sexes can generally be found resting during the day on trees or in sunny spots.

Egg to Moth

Females generally spend the day at the base of trees, climbing up at dusk to attract a mate and lay eggs. The female can be carried by the male if disturbed during mating. Females will lay groups of eggs on a wide range of broad leaved trees and shrubs including oak, birches, hawthorn and heather. The eggs are laid on the tips of twigs or in cracks in bark, and hatch in the spring. The white-striped green caterpillars can produce silken thread that they can use to ‘balloon’ on the breeze to another food plant. Winter moth caterpillars that escape being fed to nests of tits and other insectivorous birds during the spring will feed until mid-summer, before dropping to the ground to pupate.

Mistaken Identity

There are a few species that are similar to the Winter moth including the Northern winter moth (Operophtera fagata). Male Northern winter moths tend to have paler, shinier wings than the Winter moth and the hind wings often peak-out from under the forewings. The female Northern winter moth is again flightless but has longer wings than the female Winter moth (at least half the length of the abdomen).
While walking in woodlands during winter, look out for mixed flocks of tits and treecreepers. There is often a trail of winter moth wings scattered at the base of trees once the flock has passed by!

Habitat

Woodlands, hedgerows, orchards, gardens

Did you know?

Blue tits time their breeding to coincide with the emergence of Winter moth caterpillars in Spring.  A single brood of Blue tits can eat up to 10,000 caterpillars!