July 14, 2022

The Minnesota Department of Agriculture (MDA) is preparing to treat two areas in Lake County to slow the spread of a gypsy moth (now known as spongy moth). Officials will conduct the aerial treatment July 18-20, beginning as early as 6:30 a.m. each morning and continuing throughout the day. The dates and times are dependent on weather conditions in the area.

The two areas in Lake County, Two Harbors NE and Upland Trail, total approximately 45,100 acres. The Two Harbors NE area includes Gooseberry Falls State Park, and the Upland Trail area is completely within the Superior National Forest. Residents can look up their address on an interactive map to determine if they are within either of these blocks.

The MDA will use a method of mating disruption involving the aerial application of an organically certified, waxy, food-grade substance containing pheromones specific to gypsy moths that confuses the male moths. This makes it difficult for the male moths to find females for mating, which means reduced mating success. The result is fewer caterpillars hatching and attacking trees next year. The application is timed just as adult moths emerge in early summer.

The mating disruption product will be applied by low-flying yellow planes contracted by the U.S. Forest Service in a joint project with the MDA. These planes fly approximately 150 feet above the treetops and will be traveling outside the treatment areas as the planes navigate through the gypsy moth infestation sites. The product is not harmful to humans, animals, birds, or other insects, and will help protect forest health, property values, and the state’s tourism industry.

To help area citizens stay informed, the MDA has set up a Report a Pest information line at 1-888-545-MOTH (6684). The hotline will offer the latest details about treatment dates and times. Residents can sign up for updates about treatment progress by texting “MDA LAKE” to 468311 to receive text notifications or texting “MDA LAKE [your email address here]” to 468311 to receive email notifications.

Gypsy moths are among America's most destructive tree pests, having caused millions of dollars in damage to Eastern forests. The moths are now threatening Minnesota. If present in large numbers, gypsy moth caterpillars can defoliate large sections of forest. Oak, poplar, birch, and willow are among their preferred hosts. The moths spread slowly on their own, but people can unintentionally help them spread by transporting firewood or other items on which the moths have laid their eggs.

Contact the Minnesota Department of Agriculture at 1-888-545-6684 or ReportAPest@state.mn.us with questions regarding gypsy moth and the planned treatment.

Gypsy Moth Name Background

As of July 2021, the Entomological Society of America (ESA) discontinued the use of “gypsy moth” as a common name for Lymantria dispar. A new common name, spongy moth, was selected by the ESA on March 2, 2022. The Minnesota Department of Agriculture will begin phasing out the discontinued common name and adopting the new common name over the next year in accordance with state and federal regulations.


Media Contact
Allen Sommerfeld, MDA Communications