James Boone Holladay, Fort Bend County Extension Agent – Horticulture
June 10, 2019
While driving around Fort Bend County, it doesn’t take long to notice the masses of white webbing in the canopy of many species of trees. These unsightly webs are built by the Fall Webworm, Hyphantria cunea.
These, as are many regional pests, are cyclical in their populations. It indeed has been a rough year for them, most likely because of our mild winter and overwintering populations flourishing. This, combined with a wet spring, caused populations to explode.
Controlling these pests with chemicals is generally not effective, as the webbing safeguards the caterpillars from direct contact with chemical products. Further, the higher the nests are in trees, the harder it is to make good contact with the nests.
If you must, what I tend to recommend is simple. If you have a telescoping pole tree trimmer, use it to rake open the webbing. If you don’t have this tool, purchase 3 or 4 lengths of 1/2 inch PVC and use couplings to mount them together. Either way, use these to tear open webbing clusters.
Soon, predators such as wasps, lizards, and birds will begin to snack on the caterpillars and quickly their numbers will diminish. Avoid blanket applications of broad spectrum pesticides, as these will impact populations of your beneficial predators more than it will the pest itself.