A significant number of moths have been recorded in a band of counties extending from Lucas east to Ashtabula and south to Belmont. One generation is produced each year. Shortly after they hatch, young larvae climb into the tops of trees in response to light. Many of these small caterpillars will suspend themselves on silken threads and be picked up by wind currents and carried into trees from a few feet to several miles away. Gypsy moth larvae pass through five or six growth stages, called instars.
Most defoliation is caused by the last two instars.
Pupation requires about two weeks. Male moths usually emerge first and fly in a characteristic zigzag manner during daylight. Female moths are off-white with yellow to buff colored markings on their abdomens, black markings on wings, and a wingspread of approximately 2 inches. Mating occurs and the female lays eggs shortly thereafter. The male dies after mating, the female after egg laying.