

Female moths are white with brown markings.
#ACORN CAMPGROUND NEW JERSEY SKIN#
The hairs on their backs can cause mild to moderate skin irritation in some people. They have five pairs of raised blue spots followed by six pairs of raised red spots along its back. The caterpillars grow to about 2.5 inches in length. As a caterpillar grows, it can eat older, tougher leaves. Young caterpillars need to eat tender new leaves. It hatches about the time oak buds start to open. The larval stage of the spongy moth is a caterpillar that hatches in the spring from eggs laid the summer before. Evergreens do not regrow leaves as easily as deciduous trees and can die as a result of complete defoliation. When populations of spongy moths are very high, or when oak and other preferred trees are limited, they will even eat evergreen species including pine, spruce and hemlock. Tree death can occur when other stresses such as disease or other insect outbreaks attack trees in the same year. However, defoliation does reduce the vigor and resistance of the tree, and it becomes more susceptible to pests and diseases. Deciduous trees (trees that lose their leaves each fall) can regrow a new set of leaves by July and can usually withstand 2-3 successive years of defoliation (removal of leaves) without being killed. Spongy moth caterpillars eat young, tender leaves in the spring. Although spongy moths do not pose a major threat to New York's forests, they are not native and their populations can reach high, destructive (outbreak) levels. When outbreaks occur and populations are high (every 10-15 years in NY), thousands of acres of trees can be damaged. Forest Service (leaves DEC website), the current "invasion front" stretches from North Carolina across to Minnesota and includes: Maine, New Hampshire, Vermont, New York, Massachusetts, Rhode Island, Connecticut, Pennsylvania, Delaware, Maryland, Michigan, Wisconsin, Minnesota, Illinois, Indiana, Ohio, West Virginia, Virginia, and North Carolina. population in Medford, Massachusetts.Īccording the U.S. Even though they failed as a textile producer, some of the spongy moths escaped and established their first U.S. in the hope that they could breed with silkworms to create a hardier variety of silkworm and develop a silk industry in the US. Spongy moths were accidentally introduced in 1869 when they were brought to the U.S. Outbreaks are usually ended by natural causes such as disease and predators. Instead, it may take about 3 years for the small mammal population to decrease enough to allow for a spongy moth outbreak.

However, acorn crop failures do not lead to an immediate boom in spongy moth populations. Low numbers of mammals can allow spongy moth populations to rise, reaching outbreak levels. This decreases the food source for small mammals, which are predators of spongy moth. Acorn production is cyclical and varies by tree species, but there are years when crop failures align for all species and no acorns are produced. These population cycles are driven by predator-prey interactions, specifically the interactions between spongy moth, small mammals, and acorn production. Populations vary during the cycle, from years with few caterpillars and very minor damage, to years with large numbers of caterpillars and very noticeable leaf damage and tree defoliation. Spongy moth populations rise and fall in cycles of roughly 10-15 years. Spongy moths have "naturalized" in our forest communities and so they will always be around.

In New York, spongy moth caterpillars are known to feed on the leaves of a large variety of trees such as oak, maple, apple, crabapple, hickory, basswood, aspen, willow, birch, pine, spruce, hemlock, and more. The spongy moth ( Lymantria dispar dispar) is a non-native insect from France.

See our spongy moth factsheet (PDF) for quick facts about this species. Department of Agriculture, About the Insect
