Airplanes will fly low over parts of Licking County this week to drop little invitations to male spongy moths to meet up for a good time with female moths.

Except that there are no females at this party, and the males will be so confused that they won’t have any mates. And that is how the Ohio and U.S. Departments of Agriculture are trying to rid the state of the destructive little pests that can devastate Ohio’s forests.

The invitations to confusion come in the form of non-toxic, food-grade pheromones being sprayed over four regions of the county.

On June 12 and 13, the agriculture departments will work to disrupt the invasive species in Granville and along Beaver Run Road SE, on Brownsville Road SE south of Hanover, and west of St. Louisville. 

The species, formerly known as “gypsy moths,” is an invasive species initially introduced in the United States over a century ago, according to the USDA. The caterpillars feed on more than 300 species of trees and shrubs and are considered one of the most destructive insects in North America. 

The pest can kill trees, and infestations can cause forests to have “a barren, wintry look in the middle of the summer.”  

“The treatments that are upcoming are what we call mating disruption treatments,” explained Jonathan Shields, the spongy moth program manager for the Ohio Department of Agriculture. “Those target the adult moths, and we do that using their own biology against them.” 

Splat GM-O (Gypsy Moth Organic), a non-toxic, food-grade pheromone treatment, made to replicate the pheromones of the adult female, non-flying spongy moth, will be dropped on designated areas, confusing and attracting male spongy moths. 

The treatment, Shields said, will disrupt spongy moth mating, with the goal of stopping the population from growing. One cup of Splat GM-O is used per acre.

“The product is not harmful to people, not harmful to pets or other pollinators, because that pheromone is specific to spongy moths. It’s not even going to impact other butterflies or moths,” Shields said. “I always encourage people to learn more about it, they can visit our website.”

This week’s treatment of Splat GMO will be the second treatment for Ohio’s spongy moth population in Licking County this year. In May, the department used a naturally occurring bacterium — Foray 48B — as an insecticide to target the spongy moth caterpillar. 

“We try to use what will make the least environmental impact but be the most effective against the spread of the spongy moth, so we’ve already done some treatment this year using a larvicide,” Shields said. “That’s intended to target the caterpillars.”

He said the treatment is called BtK. “It’s a naturally occurring soil bacteria, but when it gets in the guts of the caterpillars, it impacts their digestive systems,” Shields said. “And basically, they starve to death, because they can no longer feed.”

Spongy moth populations are tracked through trapping of the male moth with the same pheromone used to disrupt mating. By luring the male moths in some of the 13,000 green cardboard traps in Ohio, the agriculture department is able to map out the areas in need of treatment.

Nine counties in Ohio are undergoing treatment for spongy moths this summer. They are Auglaize, Fairfield, Hardin, Hocking, Knox, Licking, Logan, Vinton and Washington counties.

The spongy moth program has been active for 24 years, and in that time it has pushed back the moth’s population by 60 miles. 

Such success is positive for the state, because the spongy moth can be devastating as it feeds on trees and shrubs, destroying tree canopies and killing otherwise healthy forests. 

To learn more about spongy moths or the treatments, go to the agriculture department’s website.

Andrew Theophilus writes for, the nonprofit news organization of Denison University’s Journalism program, which is supported by generous donations from readers. Sign up for The Reporting Project newsletter here.