Text and photos Aare Lindt, www.loodusmuuseum.ee
Translation Liis
Northern winter moth
Winter moth
Northern winter moth Metsa-külmavaksik Operophtera fagata
Winter moth Harilik külmavaksik Operophtera brumata
In Estonia two species of winter moths occur – the Northern winter moth and the winter moth. Both species are quite widely distributed and common, particularly the last-named. The moths are on the wing from late September to November, depending on the year and weather.
Winter moths hatch in greater numbers after the first night frosts. The males of both species are able to fly and often gather at artificial lights. Although the species are very similar, its lighter rear wings reveal the Northern winter moth. The females, with only a few millimetres long wings are unable to fly and more difficult to come across and identify.
In the evening dusk the females are invisible on the trunks of apple trees. Mating specimens however can easily be seen since the male often holds his wings erect on the back during the act.
The caterpillars of the Northern winter moth can in favourable years do damage to humid birch stands, those of the winter moth to fruit trees and ornamental trees in gardens and parks. With the snowfall the period of winter moths is ending. But next week when the weather turns warmer some winter moths looking for a wintering place will probably still be flying towards lights.
Both winter moth species winter as eggs.
Winter moth, female
Winter moth, female
