Fall brings with it pleasant weather and continued harvests from the garden. Unfortunately, it also brings the fall webworm that is often times misidentified in the region as bagworm. Their Latin name, Hyphantia cunea doesn’t make them any more attractive.

While not a worm at all, the fall webworm doesn’t seem so menacing when seen individually crawling along a windowsill or deck railing. But when seen with hundreds or even thousands of its comrades enclosed in a giant web at the end of a tree branch, it can be a site that turns your stomach.

The fall webworm spins a silky web at the end of a branch and has a voracious appetite for leaves. The web contains the dead and decaying leaves, the caterpillars and their droppings and can make the loveliest tree look terrible.

Webworms inhabit nearly 100 varieties of trees all over North America, but prefer fruit or nut bearing trees.

In spring, the overwintered pupae emerge from soil, mulch and other ground debris as little moths and begin their cycle of destruction.

Fall webworm moths lay eggs on the underside of leaves and usually go unnoticed until the eggs hatch and the tell-tale sign of the web appears. The seasonal caterpillar will feed on leaves and will increase the size of its web as needed to accommodate the colony. When they are young larvae, fall webworms have a light yellow body with two black stripes down their sides. As they grow, they develop black and orange wart-like bumps that eventually sprout white hairs.

While fall webworms do not bite or sting, it is best to avoid touching them. They can cause skin irritation and even a rash if their hairs come in contact with your skin.

While unsightly and even somewhat disturbing, the fall webworm rarely kills the tree it inhabits. Commercial growers of nuts, like pecans, need to worry about them far more than a typical homeowner, as they can severely affect the harvest. Fruit growers must also take measures to control the caterpillars.

Controlling the fall webworm without the use of chemicals can begin by removing as many webs as possible from the trees they inhabit. Simply cut the branch or branches that are infested. This is not always possible and an arborist may need to be hired to get the webs high up in the branches.

Once retrieved, the infested branches can be disposed of by first drowning the web in a bucket or barrel of soapy water. Some prefer to burn the web-infested branches, but I never suggest starting any fires unless I’m trying to keep warm. Fires are dangerous and can quickly get out of control. A few thousand webworms causing aesthetic damage aren’t worth the risk.

If cutting the webs out of the tree will cause the tree to be misshapen or over-pruned, simply cut a hole in the web to allow predators such as beneficial birds and wasps to feed on the webworms.

Rake and remove fallen leaves so as not to give the pupating webworms a place to hide when they begin to prepare for winter.

In spring, carefully examine the underside of leaves on the lower branches of trees that have been susceptible to webworms in the past. Eggs are laid in masses and are light green. Removing the eggs will drastically reduce the number of webworms in the trees come fall.

Keep in mind, your trees are likely to survive even a heavy infestation of fall webworms. They just won’t look as nice.