MSU Extension Integrated Pest Management

Gypsy moth

Insect

Gypsy moth

Lymantria dispar (L.)

Lepidoptera: Lymantriidae

Distribution: Most fruit-growing states and provinces in eastern North America.

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View our gypsy moth information for homeowners and land managers

The following information on gypsy moths is for fruit farmers.

The adult male is brownish and marked with blackish zigzag lines (A). The adult female is whitish with brown transverse zigzag stripes (B) and does not fly. The masses of oval and yellow eggs are laid on the trunk of trees and covered with hair left by the female. The blackish caterpillar (C) has a yellow head, long hairs, and bears tubercles on its back (four blue followed by six red).

• Crops Affected: apples, cherries, peaches, pears, plums

  Damage

  Most species of deciduous trees are susceptible to attacks from the gypsy moth (D), and apple trees are minimally affected. Eggs are laid in large masses and the abundance of caterpillars can cause the defoliation of young trees.

  Management

  Use localized intervention on trees that are severely affected. Selective insecticides (e.g., Bacillus thuringiensis) can be used, particularly against small airborne larvae that can show up from adjacent areas during bloom and cause noticeable foliar feeding; broad-spectrum insecticides can also be used, post-bloom.