Winter Moth

Operophtera brumata

The winter moth 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 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. Source

Where it is now

In the last 8 weeks this insect was recorded 94 times across 7 areas (each area is a 5 degree square).

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Movement and weather

Over the weeks it was present in the past year, its centre in Europe ranged from 48°N in December to 61°N in October, about 1,500 km apart.

Arrival dates

The week it was first heard regularly in each region, after at least six weeks away. Dates differ from south to north, so a region has a range.

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Figures are effort corrected and come from automatic sound identification, which makes mistakes. How this is measured and how it compares with human observers.