Weekend spraying targeted spongy moth caterpillars

by Kate Shunney

As predicted by forestry and agricultural experts, this year’s emergence of spongy moth (formerly known as gypsy moth) caterpillars is bigger and more destructive than last year.

The caterpillars, which eat the foliage of hardwood trees and other flora, pose a noticeable risk to forested areas in our region, including the tops of Morgan County’s most prominent mountains – Sleepy Creek, Cacapon and Sideling Hill.

Over the Mother’s Day weekend, local residents took note of low-flying helicopters which took turns spraying a pesticide targeting caterpillars before they cripple local forests.

Trees can withstand defoliation one season, but a second year of having their leaves stripped can kill some trees. Gypsy moth damage was clearly visible last spring and summer in areas affected by the pests.

Ag experts advise that tree mortality after two years of defoliation can reach 80%, meaning trees that were stripped of leaves last year by the spongy moth caterpillars are more susceptible to damage this year.

As reported in the April 10 edition of The Morgan Messenger, officials with the U.S. Department of Agriculture Gypsy Moth suppression program had already counted high numbers of moth egg masses earlier in the year and expected the emergence of caterpillars with heat and spring rains.

The larvae go through five or six stages before becoming moths in July. During that time, the caterpillars feed on hundreds of different types of trees and shrubs. The moths prefer hickory-oak forests but will attack most other local hardwoods too.

More than 2,800 acres of Morgan County were sprayed by treatment chemicals in 2023.  An additional 35 landowners signed up for this spring’s spraying, at a cost to them.

Aerial spraying this past weekend included the top of Cacapon Mountain, leading to the closure of some upper trails at Cacapon State Park to reduce the impact of spraying on park users.

Private landowners can sign up for the spraying program if their property includes a high concentration of egg masses, and they meet other participation requirements. Information about that application process can be found by emailing Gypsy Moth Program Coordinator G. Scott Hoffman at or calling 304-788-1066.

Landowners can take additional steps on their property if spongy moth caterpillars are abundant.

The trunks of affected trees can be wrapped with sticky materials to stop caterpillars from reaching upper leafy branches, and caterpillars can be removed manually and disposed of to reduce the moth population.