Hodges#7436

Pronunciation

How to pronounce Operophtera brumata: /ˌɒpəˈrɒftə ˈbruːmətə/

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Summary

Operophtera brumata, also known as the winter moth, is an invasive species in North America that originally hails from Europe. It is known for its unique life cycle, where the active adult phase occurs during late autumn and early winter, making it one of the few lepidopterans active in cold weather. The moth can cause extensive defoliation to various trees, significantly impacting local ecosystems and economies.

Physical Characteristics

Wingspan is 28–33 mm. Males have wings and can fly, while females are virtually wingless with rudimentary wing stubs. The forewing ground color of the males varies from grey-yellow to beige-brown, and the hindwings are pale grey or yellow grey. Body length for both sexes is approximately 1 cm; larvae are initially 0.1 inches (2.5 mm) long and can grow to 0.75 inches (19 mm).

Identification Tips

In North America, it can be confused with the native Bruce spanworm (Operophtera bruceata). Females have vestigial wings, while males are fully winged and have standard moth characteristics.

Habitat

Found in deciduous forests and areas with ample leaf cover for feeding, typically near their host plants.

Distribution

Native to Northern and Central Europe, introduced to North America in Nova Scotia and has spread to coastal New England and parts of the Pacific Northwest (Oregon, Washington, and British Columbia).

Diet

Larvae feed on willow, trembling aspen, paper birch, balsam poplar, bigleaf maple, and oak species, particularly Quercus robur after bud break.

Life Cycle

Overwinter as eggs, which hatch in early spring. Larvae feed on expanding leaf buds and foliage for about six weeks, then pupate in the soil in late May. Adults emerge in mid-late November.

Reproduction

Females lay between 150 and 350 eggs in various sheltered locations such as bark crevices, under lichens, or on branches after mating. Larger females tend to lay more eggs.

Predators

Wasps (Agrypon flaveolatum) and flies (Cyzenis albicans) are parasitic natural enemies affecting winter moth larvae.

Ecosystem Role

As a herbivore, it plays a role in the food web, but as an invasive species, it disrupts local ecosystems by causing defoliation of trees.

Economic Impact

Defoliation by the winter moth affects forestry and ornamental tree health, leading to economic losses in affected regions.

Collecting Methods

• Pheromone traps deployed during mating season
• Manual collection of larvae in spring
• Monitoring for defoliation signs on trees

Preservation Methods

• Freezing specimens for long-term storage
• Drying and mounting for display or research purposes

Evolution

The winter moth has shown evolutionary adaptations related to climate change, specifically in the timing of egg hatching in relation to leaf bud opening.

Similar Taxa

• Operophtera bruceata

Misconceptions

Some may confuse it with native species without knowing the significant impact of its invasiveness in North America.

Tags

• Invasive Species
• Forestry Pest
• Lepidoptera
• Geometridae
• Winter Moth