sprayed our pecan grove with an insecticide to control emerging pecan weevils and stinkbugs. A few days later, I reported seeing many fall webworm egg masses on the underside of pecan leaves. Actually, I found these eggs masses while spraying some young trees to control weevil. Three days after making an application of Warrior insecticide, fall webworm larvae started to emerge from their eggs. Once they emerged they contacted the pesticide and started dying. In the photo above, all the dark colored larvae have been dead for quite some time. The yellow larvae are still alive but are so sick they can't make it off the egg mass to start feeding on green leaf tissue. These larvae will die shortly.
As it turn out, my efforts to control weevil and stinkbugs have also controlled fall webworm.