Winter moth

The Winter Moth (Operophtera brumata) is a moth of the family Geometridae. It is an abundant species of Europe and the Near East and one of very few Lepidoptera of temperate regions in which the adults are active in the depth of winter.

The female of this species is virtually wingless and cannot fly, but the male is fully winged and flies strongly.

The moth's eggs hatch in the spring when temperatures average around 13°C (55°F). After hatching, the young larvae crawl up tree trunks and produce silken thread that can carry them in the wind to new areas. This dispersal method, called "ballooning," is common among defoliators.

Symptoms
The caterpillars tunnel into buds where they feed. These caterpillars move from bud to bud as they feed. Delayed bud opening due to cool weather conditions can lead to bud death as the caterpillars have longer time to feed.