White Ermine Moth / Fall Webworm Moth

Natural Habitat

Found in forests, woodlands, urban gardens, and agricultural lands across North America and parts of Europe/Asia.

Diet & Feeding

Adults do not eat; larvae (caterpillars) are generalist feeders on the leaves of over 600 species of trees and shrubs, including walnut, cherry, and crabapple.

Behavior Patterns

Nocturnal and attracted to light. Females lay egg masses on the undersides of leaves; larvae build large silken tents (webs) at the tips of branches to feed safely from predators.

Risks & Benefits

Larvae cause aesthetic damage to trees through defoliation and web building, but rarely kill healthy trees. They serve as a vital food source for birds, and adults act as minor pollinators.

Identified on: 5/1/2026