Ailanthus Webworm Moth

Scientific Name: Atteva aurea

Order & Family: Lepidoptera (Moths and Butterflies), Yponomeutidae (Ermine Moths)

Size: Wingspan typically ranges from 20 to 30 mm (0.79 to 1.18 inches).

Ailanthus Webworm Moth

Natural Habitat

Found in areas with the Tree of Heaven (Ailanthus altissima), its primary host plant. This includes urban areas, disturbed lands, roadsides, and open woodlands where the tree is prevalent.

Diet & Feeding

In its larval stage (caterpillar), it exclusively feeds on the leaves of the Tree of Heaven (Ailanthus altissima). Adult moths feed on nectar from various flowers.

Behavior Patterns

The caterpillars are gregarious, spinning communal webs on the Tree of Heaven, where they feed and pupate. They can defoliate portions of the host tree. Adults are active during the day and are often attracted to lights at night. They can have multiple generations per year.

Risks & Benefits

Generally considered a beneficial insect as its larvae can help control the invasive Tree of Heaven by defoliating it. This can reduce the growth and spread of the tree. There are no known risks to humans.

Identified on: 9/15/2025