The species Hyphantria cunea reside from southern Canada to northern Mexico.
This organism was then introduced in Yugoslavia in 1940 and has spread throughout Europe since. Larva webworms spin a web-like tent on the branches of hardwood trees such as apple and birch. The tents cause no harm to the trees, and the webworm uses a silk zip-line to move to a new tree. These tents provide safety as they enclose the larva while they feed, hence the name Fall Webworm.

Larvae Tent

Ecological Niche
Larva are used as primary hosts for their predator the Ichneumon wasp. The wasp obtains a Fall Webworm, and penetrates it's epidermis with their ovipositor. Proceeding this step, the wasp deposits it's eggs inside the webworm while the worm is still alive. The worm lives until it is eaten from the inside out by these wasp larva.
Adult Fall Webworms share a common environment with many other organisms as well. They aide in the reproduction cycle by being primary pollinators of specific flowering plants. They are also a primary food source of nocturnal and diurnal predators, such as bats, and swallows.
During warm weather you can usually find these species on your typical bug zapper.