Gypsy Moth In North America

The gypsy moth is not native to North America and when it was accidentally introduced here in 1869, all of its parasitoids from its naitive range were not present. Beginning in the late 1800's efforts were made to introduce gypsy moth parasitoids from Europe and Asia. Most of these species became established but a few introductions were unsuccessful because alternate hosts were not present. The role of parasitoids in gypsy moth dynamics remains unclear but it is certain that they do contribute to maintaining populations at low densities although this is never completely successful. Unfortunately some of the early introductions failed to eliminate hyperparasitoids (parasitoids of parasitoids)r and this has reduced the effectiveness of these agents. Some of these agents are generalists (e.g. Compsilura coccinata and there is concern that their introduction may have adversely affected naitive lepidoptera.