May 26, 2020

The Minnesota Department of Agriculture (MDA) is planning to treat two areas in southeast Minnesota, one near Hokah in Houston County and another near Oak Center in Wabasha County, to eradicate gypsy moth infestations detected in those areas last fall. Officials plan to conduct the aerial treatments on Friday, May 29, starting as early as 5:25 a.m. The Hokah area will be treated first. This is dependent on weather conditions at the time.

This is the first of two aerial applications of Foray/Bacillus thuringiensis var. kurstaki (Btk) over each of the areas. The second will take place in 5-10 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, and residents can sign up for email or text updates about treatment progress. Finally, 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 5:25 a.m. Residents in and around these treatment areas, 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 areas:

Hokah, Houston County: The treatment area is approximately 1,620 acres and is 1.5 miles west of Hokah. Union Ridge Road runs through the middle of the proposed treatment area (SEE MAP).

Oak Center, Wabasha County: The treatment area is approximately 1,420 acres and is located approximately three miles north of Zumbrota Falls. US Highway 63 runs through the middle of the area (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 treatments.


Media Contact
Allen Sommerfeld, MDA Communications