Common name: Spongy moth (formerly known as gypsy moth)
Scientific name: Lymantria dispar dispar
Hosts: Spongy moth is a general feeder, attacking many different tree species. Populations fluctuate from year to year, but when numbers are low, oaks are the preferred host. Other susceptible species include alder, apple, aspen, birch, hawthorn, larch, and linden. Certain tree species show some resistance in that they are not fed on by early stage caterpillars. These species include beech, dogwood, elm, hemlock, maple, pine, Prunus species, serviceberry, spruce, and walnut. Trees considered immune, since caterpillars almost never feed on them, include arborvitae, ash, black locust, fir, holly, juniper, redbud, sycamore, tulip tree, and tupelo (Nyssa).
Spongy moth, Lymantria dispar dispar, was introduced into this country in 1869 and has since become a serious pest in the northeastern part of the United States. In some areas it has changed the ecology of native forests, defoliating more than 13 million acres of woodlands in one season. In more recent years, the spongy moth invasion has slowly moved westward, with established populations in Michigan, Wisconsin, Indiana, and Illinois. .