By Blake Jackson
If you notice silky webs on tree branches in late summer and early fall, you’re likely seeing the work of fall webworms. These pests are common across North America and are especially active during the warmer months.
Fall webworms are caterpillars that build grayish-white webs around tree limbs and leaves. They’re often confused with Eastern tent caterpillars, which appear in spring, but fall webworms are a late-season problem. Though not a serious threat to forests, they can defoliate shade trees and ornamentals, weakening them over time.
These pests feed on over 100 types of trees, with pecan, oak, and fruit trees being their favorites. Adult moths emerge between May and August, laying egg clusters under leaves. The young larvae are pale green with a dusky back stripe and yellow side lines. As they grow, they become hairy and vary in head color from red to black.
The webs serve as protection for the feeding caterpillars and can cover several branches on heavily infested trees. Even after the worms are gone, the webs often remain, making trees look damaged and messy.
Fortunately, the damage to most trees is minor. The best way to control fall webworms is to prune out the affected branches with the webs and destroy them. Though chemicals can kill the caterpillars, they’re not always practical for large trees. If you choose to spray, ensure the insecticide reaches inside the web for best results.
Maintaining healthy trees and regular monitoring can help reduce future infestations. Recognising the signs early and taking simple action can protect your landscape from long-term damage.
Photo Credit: istock-georgeclerk
Categories: Pennsylvania, Crops, Fruits and Vegetables