Extension

Camping enthusiasts are often found pitching a tent when they’re enjoying a weekend in the great outdoors. Tent caterpillars do the same thing by gathering at branch forks and crotches in trees and shrubs and spinning their tent-like webs. The webs are produced through glands in their head and the tents protect from predators.

 

This is the time of year when the tents of the eastern and western tent caterpillars can be seen alongside roads. Oklahomans in the southeastern three-fourths of the state will find the eastern tent caterpillar, while the western tent caterpillar is found in the northwestern one-third of the state. They typically hatch around the middle of March and begin work on their tents. As the caterpillars grow, so do their tents.

 

While building their homes, they also feed on new leaf growth. This feeding continues into early May when the caterpillars pupate, with the adults emerging in late May.

 

The eastern tent caterpillar favors members of the Prunus genus, including black cherry, wild plumbs, apple and crabapples. Although the western tent caterpillars also feed on Prunus, they are found in oak, willow, poplar, birch, ash and redbud trees.

 

Unless the population of the tent caterpillars is large enough to defoliate a tree by feeding, damage typically isn’t too severe. Gardeners can use the manual control method of clipping the tents from the limbs and destroying them. It’s best to do this process on cool, rainy days or after dark when the caterpillars are still small. The larvae don’t venture out of their tents to feed during inclement weather.

 

Although there are a variety of insecticides available, sufficient spray pressure is needed to reach and penetrate the tents. A bacterial insecticide called Bacillus thuringiensis can provide caterpillar control and is considered to be more environmentally safe when compared to some of the general-purpose insecticides.

 

Don’t confuse tent caterpillars with webworms, which appear later in the year. Fall webworms usually are spotted sometime in June with another wave appearing a bit later in the fall. These caterpillars encase the leaves they feed on in the web, so their webs are typically found toward the tips of the branches as opposed to the branch forks and crotches that tent worms call home.

 

Webworms prefer pecan, black walnut, persimmon and hickory trees but large infestations will feed on other species, too.