Fall Webworm

Now is the time that we are seeing a lot of fall webworm on trees in our area. We are seeing the second generation of webworms; the first generation was small and unnoticed. Unlike tent caterpillars, webworms eat inside their webs. As food is consumed, they enlarge their nest. I snapped this picture (above) of webworm on crabapple. If you open the nest, you will see the webworm larvae (pictured below).

Since damage occurs so late in the season, control is optional. High populations can completely defoliate host plants, but plants typically recover. In some cases, host plants can become stressed leading to other problems if webworms are not controlled.

The easiest method of control is to remove and destroy infested portions of branches while webs are small. If you want to control populations of webworms using plant protection products, apply them when webs are small (before much foliage has been destroyed). A tree company (like Ryan Lawn and Tree) can assist you with chemical control if necessary.