Fall Webworm in Atlanta Trees: Identification & Management Guide

What Is Webworm?

Webworms are the larvae (caterpillars) of the fall webworm moth, Hyphantria cunea, a native insect in the moth family Erebidae that builds large silken nests on the tips of tree branches. The caterpillars feed on leaves inside the web, gradually enlarging the nest as they grow and as more foliage is consumed.

How to Recognize It

• Loose, dirty looking silken webs wrapped around the ends of branches, often containing leaf fragments and caterpillar droppings.
• Skeletonized or chewed leaves inside the webbing, with brown, dead foliage as the nest expands.
• Hairy caterpillars about one inch long, pale green to yellow or tan, with rows of dark spots and tufts of long white and black hairs.
• Webs that start small around a single leaf cluster and grow over weeks to cover entire branch tips.
• Bare branch ends on otherwise leafy trees, usually in mid to late summer.
• Multiple separate nests scattered across the canopy in heavy years.

In the Atlanta area, webs typically appear from mid summer through early fall. Because Georgia can see two to five generations per year, nests often become most noticeable in August and September.

Why It Matters for Atlanta Trees

Fall webworm looks alarming but is rarely fatal to established, healthy shade trees, since most webs are confined to branch tips and feeding occurs late in the growing season after the tree has already stored energy for the year. Around Atlanta, the caterpillars show a strong preference for pecan, hickory, black walnut, persimmon, sweetgum, maple, oak, river birch, mulberry, and cherry and other fruit trees, so these species are worth checking first. Young, recently planted, or repeatedly defoliated trees can be stressed by the feeding and become more vulnerable to drought, disease, or other pests, which is where early detection matters most.

General Prevention

• Inspect susceptible trees (pecan, hickory, walnut, sweetgum, fruit trees) starting in midsummer, so small nests are caught before they spread.
• Keep trees vigorous with proper watering during dry spells and a wide ring of mulch over the root zone, since healthy trees tolerate defoliation better.
• Prune out small, reachable nests on branch tips when they first appear and dispose of the clippings, rather than leaving them in the canopy.
• Encourage natural predators (birds, parasitic wasps, predatory beetles) by avoiding broad-spectrum insecticide use in the landscape.

What NOT to Do

• Do not self-diagnose. Many tree problems look alike, and treating the wrong one wastes time and can harm the tree.
• Do not apply insecticides or other chemicals without an arborist's specific recommendation. Wrong product or wrong timing makes things worse, and broad-spectrum sprays often kill the beneficial insects that keep webworm populations in check.
• Do not burn webs out of the tree with a torch or lit rag. This is a common piece of bad advice that scorches bark, kills branches, and creates a real fire risk in the canopy.

Related Services

For most diagnosis and treatment questions, the right starting point is one of our services:

• ISA-Certified Arborist Services, diagnosis, consultation, second opinion.
• Plant Health Care (PHC), ongoing tree health management.
• TRAQ Tree Risk Assessment, when the tree may be a safety hazard.

Sources

This page summarizes general information from: UGA Cooperative Extension, UGA Extension Landscape Pest Management, and Clemson Cooperative Extension Home & Garden Information Center.