Lymantria dispar (L.)
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).
Most fruit-growing states and provinces in eastern North America.
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.
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.
The MSU IPM Program maintains this site as an access point to pest management information at MSU. The IPM Program is administered within the Department of Entomology, fueled by research from the AgBioResearch, delivered to citizens through MSU Extension, and proud to be a part of Project GREEEN.