Although the nest provides the webworm with quite a lot of protection from predators, they are much more vulnerable than tent caterpillars. Some of the main predators of the fall webworm are birds, parasitic wasp and hornets. Birds, such as the yellow warbler, are known to repeatedly return to the fall webworm nest once it is discovered until they have emptied it of prey. Much like some birds, the hornet will discover the nest of the fall webworm and continue returning. In most cases they will attack a caterpillar that is close to the surface of the nest, but some hornets enter the nest to attack their victim.
Parasitic wasps enter the fall webworm nest, laying their eggs inside the larva.
Once they eggs hatch they wasp larva feed on the caterpillar until it dies. The last generation of fall webworms will crawl to the ground beneath their food tree, hibernating in a cocoon in the loose bark. The adult moths emerge during the last part of spring and the fertilized females deposit their eggs on the leaves of their species food source. It is interesting to note that the web nest of the fall webworm tends to protect the caterpillars from most pesticides that are used to destroy them. In most cases it is suggest that each web be torn open before applying pesticides.