Why are gypsy moth caterpillars a problem?
Gypsy moth caterpillars can damage and kill trees and shrubs by eating leaves and needles. They are considered one of America’s worst forest pests and have defoliated millions of acres of trees in the eastern U.S. Gypsy moths can spread widely in a region, and infestations can cause extensive environmental and economic damage by destroying forests as well as orchards and residential trees. There are two types of gypsy moths that have been a concern in the Seattle area. The Asian gypsy moth (AGM) tends to eat both leafy (deciduous) and needled (coniferous) trees, while the European gypsy moth (EGM) prefers to eat leafy trees. During a later period of its caterpillar growth cycle the EGM may eat evergreen needles. The Asian gypsy moth most likely came into the Seattle area off ships that had previously visited ports in eastern Russia. The AGM female can fly up to 20 miles before laying her eggs. Each female may lay up to 1000 eggs. In contrast, the EGM tends not to travel such wide dista
