Gypsy moths are notorious hitchhikers. The female moth lays her eggs on any solid surface such as tree trunks, outdoor furniture, recreational and other vehicles, firewood, bird or doghouses, toys, etc. When objects on which eggs have been laid are later moved, gypsy moths are transported with them, sometimes for long distances. Infested items brought from the northeastern U.S. are the main source of gypsy moth infestations in Oregon. Egg masses on vehicle tire.
Gypsy moths occur in North America, Europe, and Asia.
The Asian gypsy moth strain has also become established recently in Germany and other European countries where they hybridize with European gypsy moths. Asian gypsy moths have arrived in the U.S. on bulk cargo ships, ship containers, and cargo and outdoor articles from infested areas of Asia and Europe during the 1990's. These introductions in the U.S. have been successfully eradicated. Unlike their gypsy moth cousins, female Asian gypsy moths can fly and are attracted to lights, allowing the populations to spread much more rapidly. Asian gypsy moth caterpillars also develop more quickly and grow somewhat larger.