The Minnesota Department of Agriculture (MDA) is preparing to treat approximately 73,500 acres of land in the Split Rock/Beaver Bay area of Lake County to slow the spread of a gypsy moth infestation. Officials will conduct the aerial treatment July 16-18, beginning as early as 7:00 a.m. each morning. The dates are dependent on weather conditions in the area leading up to the treatment date.
To help area citizens stay informed, the MDA has set up an Arrest the Pest information line at 1-888-545-MOTH (6684). The hotline will offer the latest details about treatment date and time. Residents can also sign up for email or text notifications.
The MDA maintains a monitoring program to watch for start-up infestations ahead of the advancing population front moving into Minnesota from Wisconsin. When an infestation is found, the department conducts aerial treatments of the infestation before it can spread further westward. In 2017, the MDA found an infestation along the North Shore. In cooperation with the USDA Forest Service, the department is now treating approximately 73,500 acres, including 11,000 acres of Superior National Forest land. (SEE MAP) Details of the area can be found at www.mda.state.mn.us/gmtreatments.
The MDA will use a method of mating disruption involving the aerial application of an organically certified, waxy, food-grade substance containing pheromone that confuses male gypsy moths. This makes it difficult for the male gypsy moths to find females for mating, which means reduced mating success. The result is fewer caterpillars hatching and attacking trees next year. Application is timed just as adult moths emerge in mid-summer.
Mating disruption has been widely used for gypsy moth management in Minnesota and across the nation. Annually, close to 400,000 acres are treated with mating disruption across the United States. It is an effective tool that helps slow the spread of the insect as it moves westward across the country.
This work is being coordinated through the national Slow the Spread of Gypsy Moth program directed by the U.S. Forest Service. Minnesota has been part of this program since 2004. These efforts protect forest health, property values, and the state’s tourism industry.
Gypsy moths are among America's most destructive tree pests, having caused millions of dollars in damage to Eastern forests. If present in large numbers, gypsy moth caterpillars can defoliate large sections of forest.
Allen Sommerfeld, MDA Communications