I got a text message from a neighbor that was worried about some strange nests in her neighbor’s trees. She was worried it may be a hornets’ nest, but the problem is fall webworms. Fall webworms enclose leaves and small branches in their nests making trees look ugly. Fall webworm larvae feed on over 85 species of trees in our area including pecan, walnut, American elm, hickory, persimmon and fruit trees.

This pest begins its feeding in late summer, concentrating its nests to limited areas. Because of this, little or no real damage is done to the trees.

This pest over-winters in the pupae stage in the ground but can be in old nest remains, under loose bark and in fallen leaves. The adults emerge from late May into July laying eggs. Eggs hatch into hungry larvae feeding for about six weeks, at which time they drop to the ground to pupate. Two or more generations may occur during the summer.

The nest of sticky material is nature’s way of protecting the vulnerable larvae. Pesticide sprays cannot effectively penetrate large nests. Controlling the pest is best done by physically removing the nest. Small nests can be pruned out of small to medium trees. These small nests can be easily destroyed with a stick or cane pole. Do not burn or torch the nests in trees. This causes additional damage to the tree and is a hazard.

Parasites and predators also controls fall webworms. Yellow jackets, wasps and hornets as well as birds, predatory stink bugs and parasitic flies are important predators. Open the sticky nest with a stick and it allows easy access to birds and other predatory insects.

Darrell Blackwelder is the retired horticulture agent and director with the North Carolina Cooperative Extension Service in Rowan County. Contact him at deblackw@ncsu.edu.