Gypsy Moth, a moth native to the Eastern Hemisphere. Its larvae can cause great damage by feeding on the leaves of trees, particularly those of the oak, poplar, willow, birch, and maple. The male has a light-brown body and dark-spotted, olive-brown wings about 1 1/2 inches (4 cm) across. The slightly larger female has a buff-colored body and grayish-white wings marked with black.

There are several strains of gypsy moths. The body of the female of a European strain is so heavy that she rarely flies; females of an Asian strain fly long distances.

Gypsy moths lay spherical, yellowish eggs in clusters of 400 or more on trees, fences, and buildings in midsummer. The clusters, which are covered with brownish hair, lie dormant through the winter. The eggs hatch early in May. The hairy larvae are brownish yellow, with bluish spots on the forward segments, red spots toward the rear. When the caterpillars reach maturity in midsummer, they are about two inches (5 cm) long. They then pupate (form cocoons), emerging as moths in two to three weeks.

GypsyGypsy moth larvae are hairy with blue and red spots.

The gypsy moth became a serious pest in the United States following its accidental introduction from Europe (where natural predators keep it under control) into Massachusetts in 1869. Through the years the populations have increased and spread considerably. More than a million acres (400,000 hectares) of trees are defoliated each year. Control efforts include spraying with insecticides; exposing the moths or their larvae to natural enemies; and using synthetic sex attractants to confuse the males and prevent them from mating.

In 1991, gypsy moths of Eastern Asia were introduced accidentally into the United States and Canada. There is concern that the Asian strain will spread and cause destruction in western North America similar to that caused by the European strain throughout eastern North America.

The gypsy moth is Lymantria dispar of the tussock moth family, Lymantriidae, of the order Lepidoptera.