Winter moth

The winter moth (Operophtera brumata) is a moth of the family Geometridae. It is an abundant species in Europe and the Near East and a famous study organism for evaluating insect population dynamics. It is one of very few lepidopterans of temperate regions in which adults are active in late autumn and early winter. The adults use endothermy for movement in these cold temperatures. The females of this species are virtually wingless and cannot fly, but the males are fully winged and fly strongly. After the initial frosts of late fall, the females emerge from their pupae, walk to and up trees and emit pheromones in the evening to attract males. After fertilization, they ascend to lay, on average, around 100 eggs each. Typically, the larger the female moth is, the more eggs she lays.

The winter moth is considered an invasive species in North America. Nova Scotia, Canada, experienced the first confirmed infestations in the 1930s. It was later accidentally introduced to Oregon in the 1950s and the Vancouver area of British Columbia around 1970. Defoliation by the moth was first noted in eastern states of the United States in the late 1990s, and is now well established in Massachusetts, Rhode Island, New Hampshire and Maine. The winter moth is confirmed present in British Columbia, Washington and Oregon. In Massachusetts, the moths have attracted the attention of several media outlets due to the severity of the infestation. Efforts at biological control are underway.