I have received numerous calls in the past month asking my advice on fall webworms. The appearance of these bug-filled webbings on outer tree branches can be seen all around the Mid-South. Some of the trees that I have seen lately are fully covered with webworm tents. Although it is unsightly, damage from the fall webworm is most often inconsequential, since trees will soon lose their leaves.

Here in the south, host trees include persimmons, pecan, ash, black walnut, hickory, and oak.

There can be up to two different generations of webworms produced in the same year. During high population densities, small to moderate-sized trees may be completely covered with webbing. It has also been reported that the caterpillars may migrate from one tree to another.

The caterpillars inside the webbing are about an inch long. They are generally light colored and covered with tiny bumps from which arise tufts of long, light-colored hairs. The head is either orange-red or black. The adult moth lays hairy masses of eggs on the undersides of tree leaves that will hatch and begin to develop in about two weeks. Newly hatched larvae immediately begin to spin webbing over the foliage they are feeding upon. As the larvae grow, they enlarge the web nest to enclose more foliage.

If the webs become a nuisance, there are a few control measures that you can explore. One way to control webworms is to prune out and destroy the webs within reach. If you can’t prune them out, tear the web open and let Mother Nature handle the problem for you. Finally if the tree is badly infested, you can use a labeled insecticide to protect that tree. Be sure to follow the directions on the label!

Although fall webworms are back with a vengeance, remember their impact is minimal. You can let nature take its course and do nothing. Even if webworms defoliate your tree, it's usually late enough in the season that it doesn't impact your tree.

Until next time, happy gardening!