May 20, 2021

The Minnesota Department of Agriculture (MDA) is planning to treat an area in New Hartford Township, Winona County, to eradicate a gypsy moth infestation detected in the area last fall. Officials plan to conduct the aerial treatment on Saturday, May 22, starting as early as 5:30 a.m. The treatment will take approximately two hours to complete. This is dependent on weather conditions. A Friday, May 21, treatment may be necessary if forecasted rain prevents a Saturday treatment.

This is the first of two aerial applications of Foray/Bacillus thuringiensis var. kurstaki (Btk) over the approximately 1,140-acre area. The second will take place in 5-14 days. Btk is a biological product that is organic certified for food crops. It has no known health effects for humans, pets, birds, fish, livestock, bees, and other non-caterpillar insects.

To help area citizens stay informed, the MDA has set up an Arrest the Pest Info Line at 1-888-545-MOTH with the latest details about treatment dates and times. On the morning of the treatments, residents can call the phone number with any questions they may have. Simply press 0 (zero) to speak to someone. The MDA's website ( also has information about gypsy moths and control efforts. Residents can sign up for updates about treatment progress by texting “MDA WINONA” to 468311 to receive text notifications or texting “MDA WINONA [your email address here]” to 468311 to receive email notifications.

The MDA offers the following tips to residents in the treatment area:

  • For the gypsy moth treatment to work, it must begin early in the morning. Treatments may begin as early as 5:30 a.m. Residents in and around the treatment area, up to a half mile outside of the treatment area, may be awakened on that day by the noise of a low-flying airplane. The MDA apologizes for any inconvenience.
  • The treatment product has no known health effects for humans, but residents may wish to stay indoors during the treatment and keep windows closed for a half hour after application. Residents can cover gardens or turn on sprinklers during the treatment if they wish.
  • The residue does not cause damage to outdoor surfaces. However, soapy water will remove any residue on outdoor items.

Treatment area: The treatment area is approximately 1,140 acres in New Hartford Township, Winona County. County Highway 16 and Pea Ridge Road run through the treatment area (Also referred to as the Pea Ridge Block – SEE MAP).

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 with questions regarding gypsy moth and the planned treatment.


Media Contact
Allen Sommerfeld, MDA Communications