The Bug Days of Summer: Fall webworm activity picks up

by | Aug 12, 2015

Forestry-Files-740x420If the grilling display being replaced by school supplies at your local store wasn’t clue enough, then allow these pests to send the message: Summer is coming to an end! And the fall webworm, a caterpillar that is active in late summer and early fall, is already raising its ugly web to remind us.

The fall webworm reminds us that summer is near its end.  Image: K. Oten, NCFS.

The fall webworm reminds us that summer is near its end. Image: K. Oten, NCFS.

Fall webworms are notorious for the webs they make at the ends of tree branches. They are easily noticed and many consider them quite unattractive, especially when they infest a yard or ornamental tree.  We may have a different opinion if it were October – free Halloween decorations, anyone?

The caterpillars themselves eat the tree leaves that are within the nest, causing localized defoliation. As the caterpillars grow, the nest expands, encompassing more and more leaves needed for food. They live in groups, so in a single web, there are many caterpillars. They feed on many species of deciduous trees, such as sourwood, walnut, persimmon, and more. A closer inspection of the web will reveal excrement and shed skins of the caterpillars all left within their nest home. These dirty living quarters may remind you of your teenager’s room!

Instead of grounding them for the mess they made, it is generally recommended not to worry about these web makers. Even when there are many nests of a single tree and it is nearly entirely defoliated, trees do leaf out the following year and there is little long-term impact on tree health. In severe cases, the best management method is to remove the nests and destroy them.

So, relish the last days of summer the fall webworm warns are upon us! It will be sweater weather in no time!