Battle against spongy moths to resume in DuPage forest preserves

Once again, the Illinois Department of Agriculture will be tackling an ongoing environmental problem in DuPage County. But there's a slightly newer name attached to the invasive species of moths classified as Lymantria dispar, which were previously known as "gypsy moths."

Last July, the Entomological Society of America officially dropped this common name for the destructive insect because it has historically been an ethnic slur against Romani people. According to the University of Wisconsin-Madison Department of Entomology, the new common name is "spongy moths" since it visually describes the appearance of egg clusters laid by the female moths.

To slow the spread of spongy moths, the Illinois Department of Agriculture is planning another series of aerial treatments over select DuPage County Forest Preserve District sites.

On June 27 and 28, the state agency will deploy a low-flying airplane to spray a "pheromone mating disrupter" over the preserve sites of Waterfall Glen near Darien, Des Plaines Riverway near Burr Ridge, Hidden Lake near Downers Grove and Wood Ridge near Lemont.

"The great news about a pheromone treatment is that it is a nonlethal way to control the spongy moth population," said Andres Ortega, an ecologist with the DuPage County Forest Preserve District.

Ortega said the mimic of the female moth's pheromone is attached to a wax-based product that biodegrades. The intended effect is tricking the male moths into thinking female moths are there, so they will hopefully exhaust themselves trying to seek nonexistent females.

"You waste their time until those males expire, and then you have many, many less eggs laid that year - ideally," Ortega said. "The goal is not a direct control for this season, but more for the future next year."

Spongy moth caterpillars destructively target mainly oak trees and strip them of their leaves. Ortega said even healthy oak trees will likely not withstand two or three repeated seasons of defoliation by a major infestation of spongy moth caterpillars.

"They are not likely to be eradicated, unfortunately," Ortega said. "The goal is to slow their spread."

For more information on the pheromone aerial treatments, visit the Illinois Department of Agriculture at slowthespread.org, or call the agency's DeKalb office at (815) 347-0401. For forest preserve information, call (630) 933-7200 or visit dupageforest.org.