Populations can rapidly build to large infestations causing widespread defoliation, weakening or sometimes killing trees. Defoliated forests are susceptible to disease, fire, erosion, and may provide a poor habitat for other forms of plant and animal life. Defoliation reduces the aesthetic, recreational and economic value of forests, parks, and wooded homesites. Newly infested states are subject to restrictive quarantines to prevent further spread of the insect. When numerous, gypsy moth caterpillars can become a nuisance by crawling over such objects as buildings, vehicles, roads, and lawn furniture.
Some people suffer allergic reactions when they contact hairs from the caterpillar.
Forest in spring before Gypsy Moth damage is evident. The same forest in summer after being defoliated by GM caterpillars. Life Cycle Gypsy moth egg mass. Gypsy moth caterpillar. Gypsy moth pupa.