Next Round of Gypsy Moth Aerial Treatments Planned

​​For release: June 12, 2019

Contact:  Stephanie Jentz, Public Information Officer, (608) 347-1082
              Donna Gilson, Communication Specialist, (608) 224-5130

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MADISON – The second phase of the gypsy moth aerial treatments will begin in late June, with planes applying waxy droplets containing a mating disruptor in nine counties in western Wisconsin. 

From late June to mid-July, yellow planes contracted by the U.S. Forest Service in a joint project with the Wisconsin Department of Agriculture, Trade and Consumer Protection (DATCP), will apply mating disruptor to nine sites in Buffalo, Burnett, Crawford, Douglas, Grant, La Crosse, Lafayette, Vernon and Washburn counties. Maps of treatment areas are available online

Unlike the earlier spring treatments that targeted gypsy moth caterpillars, the mating disruptor targets adult male moths.

The product is aerially applied and sprayed across the forest canopy as small waxy droplets that slowly release gypsy moth mating pheromone. Research shows this can reduce gypsy moth populations by nearly 90 percent in the following year. The mating disruptor is not harmful to humans, animals or birds. 

“Female gypsy moths do not fly. They give off a pheromone, or a chemical scent, which attracts male gypsy moths,” explained Christopher Foelker, DATCP’s gypsy moth program manager. “The product emits the same scent, and confuses the male moths, so they cannot find the females. The chemical signal is specific to gypsy moth and does not affect other insects.”

Treatment dates and times are weather dependent. People can sign up to receive up-to-date email notifications about treatment plans hear a recorded message about plans at 1-800-642-6684. Daily updates during the treatment season are also posted to DATCP’s Facebook and Twitter accounts. 

Gypsy moths defoliate trees, which may eventually kill the trees. The cost of removing dead trees can range from several hundred to over a thousand dollars, and the loss of mature trees decreases property value. During the spring and summer, caterpillars shed bristly skin as they grow. Bristles from the cast skins become airborne and can irritate eyes, skin and the respiratory system. People may develop a rash if they come in contact with the bristles.

Aerial treatments are part of the national Slow the Spread Program. It focuses its efforts in western Wisconsin, where gypsy moth populations are low or beginning to increase. The intent is to slow the westward spread of gypsy moth. 


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