MDA to fight gypsy moth in southeast Minnesota

Published 8:00 pm Tuesday, May 5, 2020

Getting your Trinity Audio player ready...

The Minnesota Department of Agriculture is preparing 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, according to a press release. Officials will conduct the treatments starting sometime between Monday and May 22, with the exact dates determined by weather conditions and caterpillar development.

To eradicate the moths before they spread, officials will conduct two aerial applications of Bacillus thuringiensis var. kurstaki over each of the areas, spaced five to 10 days apart. Btk is a biological product that is organically certified for use on 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. The info line will offer the latest details about treatment dates and times. The MDA’s website ( also has information about gypsy moth and control efforts. Residents can sign up for email or text notifications there. Finally, the MDA offers the following tips to residents in the treatment area:

Email newsletter signup

• For the gypsy moth treatment to work, it must begin early in the morning. Treatments may begin as early as 5:15 a.m. Residents in and around these treatment areas 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.

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

Gypsy moths are among America’s most destructive tree pests, having caused millions of dollars in damage to eastern forests, according to the release. 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.