The Minnesota Department of Agriculture (MDA) is preparing to treat eight sites in Houston, Wabasha, and Winona counties to slow the spread of a gypsy moth. Officials will conduct the aerial treatment June 28-30, beginning as early as 6:30 a.m. each morning and continuing throughout the day. The dates are dependent on weather conditions in the area.

The eight sites total nearly 57,000 acres. They are:

  • Houston County – Jefferson block – 2,881 acres (MAP)
  • Houston County – Mound Prairie block – 12,060 acres (MAP)
  • Houston County – Brownsville block, including portions of the city of Brownsville – 2,418 acres (MAP)
  • Wabasha and Winona counties – Weaver block – 13,004 acres (MAP)
  • Winona County – Dakota block – 9,533 acres (MAP)
  • Winona County – Homer Ridge block – 26,061 acres (MAP)
  • Winona County – Pleasant Hill block – 1,470 acres (MAP)
  • Winona County – Wiscoy block – 2,489 acres (MAP)

Residents can look up their address on an interactive map to determine if they are within any 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 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 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. 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 an Arrest the 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 SOUTHEAST” to 468311 to receive text notifications or texting “MDA SOUTHEAST [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 Arrest.the.Pest@state.mn.us with questions regarding gypsy moth and the planned treatment.