Scientists are actively looking for parasites and predators of the gypsy moth, principally in Europe and Asia. Over 10 foreign biological control agencies have been introduced for control purposes. Natural enemies include wasps, flies, ground beetles, and ants. Spiders eat many small caterpillars. Birds such as chickadees, bluejays, nuthatches, towhees, and robins are control agents as are several woodland mammals like whitefooted mice, shrews, chipmunks, and squirrels.
Gypsy moths have several diseases, caused by bacteria, fungi, or a virus.
The NPV virus disease is the most destructive to this pest. When conditions are right, it will nearly eliminate gypsy moths in an area for a few years. The disease occurs, and works best in control after a long period of rain or during very humid weather when the caterpillars are feeding. Homeowner control Homeowners can use measures that would be too costly for large forested areas. These will provide some measure of control in normal years, but none of these measures will be effective during a gypsym moth outbreak year.