Fall Webworm

*Hyphantria cunea*

Content coming soon for this insect guide.

Insect Profile

Beneficial Rating

-2 Pest

Active Months

JanFebMarAprMayJunJulAugSepOctNovDec

US Distribution

NortheastSoutheastMidwestSouthwestWestPacific Northwest

Habitat Preferences

gardenswoodlandsforest edgesroadsides

Taxonomic Group

Caterpillar

Order

Lepidoptera

Family

Erebidae

Lifecycle

The fall webworm has one to two generations per year, depending on the latitude. In late spring or early summer, the adult moth emerges from its overwintering pupal case and lays several hundred eggs on the underside of leaves. The eggs hatch in about a week to two weeks, and the larvae begin to feed. The larval stage, which is the caterpillar stage, lasts for about four to six weeks. The larvae are hairy and can be yellowish-green with a black head or tan with a red head. They construct large, silken webs at the tips of branches, and feed inside the web. Once the larvae are fully grown, they leave the web to find a protected place to pupate. The pupa overwinters in the soil, in leaf litter, or in cracks in the bark of trees.

Overwintering Strategy

Pupae overwinter in cocoons in the soil, leaf litter, or in cracks and crevices in the bark of trees.

Native Range

North America

Attracted By

mulberrywalnuthickoryelmsweetgumpoplarwillowoaklindenashappleand other fruit trees

Organic Control Methods

Organic control of the fall webworm primarily focuses on mechanical removal and the use of biological insecticides. The most common method is to prune out the webs and destroy them, especially when they are small and newly formed. This can be done by hand or with a pole pruner. For larger webs, a forked stick can be used to twist and remove the nest. Another effective organic control is the application of Bacillus thuringiensis (Bt), a microbial insecticide that is specific to caterpillars and does not harm other insects. Spinosad and pyrethrin-based products are also considered organic options.

Companion Planting

No specific companion planting strategies were found in the research. The primary organic control methods involve physical removal of nests and the use of biological pesticides.