Limited infestations have occurred in Michigan, Wisconsin, and even Utah. The larvae can feed on over 500 species of trees, shrubs and vines. The gypsy moth most favorite tree species are the oaks, which are a significant component of Cuyahoga Valley forests. Other favorites found in the park include river birch, hawthorn, and willow. Moderately desirable species that can be defoliated include cherry, cottonwood, elm, blackgum, hickory, hornbeam, maple, and sassafras.
Defoliation directly affects trees by decreasing their health and vigor.
This can result in an increased susceptibility to disease and parasites, leading to increased tree mortality. Defoliation and the loss of mature trees can change forest and understory composition, water quality in streams and lakes, quality and availability of food for terrestrial and aquatic wildlife, and quality and availability of habitat for terrestrial and aquatic wildlife. This can result in changes in the abundance and distribution of wildlife. Since the gypsy moth is a non-native species, its effects on the environment are not part of natural ecological processes and are therefore largely undesirable. Gypsy moths also present aesthetic, safety, and health concerns to employees and the public.