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News Release

State Agency to Treat for Invasive Moths in Four DuPage Forest Preserves in Late June

Low-flying airplanes will spread harmless pheromone to disrupt mating
The Illinois Department of Agriculture will conduct aerial treatments on June 27 at Waterfall Glen, Des Plaines Riverway, Hidden Lake and Wood Ridge forest preserves for nonnative Lymantria dispar moths, formerly known as gypsy moths.
The state agency will treat trees with a pheromone mating disruptor that is not harmful to people, pets, wildlife, plants, cars, or structures. The treatment will be applied by a low-flying airplane that will make multiple passes over the preserves.

The wax-based droplets may stick to cars but can easily be scrubbed off and will not damage the paint or finish. Signs will be posted at the preserve entrances on treatment days.

The treatment is part of a statewide program to prevent Lymantria dispar from establishing itself beyond northeast Illinois. The agency is also trying to reduce the impact of the moth’s invasion from other states.

For more information about the treatments, visit the Illinois Department of Agriculture’s website, call the agency’s DeKalb office at 815-347-0401, or email program manager Nancy Johnson at

Lymantria dispar is a destructive invasive pest that destroys trees and shrubs. Large populations of its caterpillars are capable of stripping plants bare, leaving them susceptible to disease and environmental stressors. Severe defoliation can kill trees. It feeds on over 250 species of plants but prefers oak and willow trees.

The Forest Preserve District of DuPage County has been connecting people to nature for more than 100 years. More than 6.2 million people visit its 60 forest preserves, 166 miles of trails, five education centers, and scores of programs each year. For information, call 630-933-7200 or visit, where you can also link to the District’s e-newsletter, FacebookTwitter, Instagram and TikTok pages.