Gypsy Moth in Minnesota
What is Minnesota Doing?
The Minnesota Department of Agriculture (MDA) has been monitoring new introductions of the gypsy moth since 1969. Since then a number of isolated outbreaks have been found and successfully eradicated. In 2004, four counties were added to the national Slow-The-Spread (STS) front. These include Cook, Lake, Houston and Winona counties. The significance for Minnesota is that it may no longer be feasible to eradicate infestations of gypsy moths in those counties because of the close proximity to the generally infested area in Wisconsin. To guide decision-making within the state, the Minnesota Cooperative Gypsy Moth Program was established in 2002. The program's strategic plan establishes agency roles and outlines management strategies for eight key components of the program.
Minnesota MDA: Gypsy Moth Program 
2011 Treatments
To combat these infestations, MDA and its federal, state and local partners propose to conduct treatments in fourteen treatment blocks along the North Shore and three treatment blocks in the Twin Cities metro area . MDA proposes to use the biological insecticide Bacillus thuringiensis var. kurstaki (Btk) for the three metro treatment blocks and one small block in Duluth. Btk targets the moth's larval stage of development and treatments typically occur in late May or early June. MDA proposes to treat the other thirteen treatment blocks using mating disruption. This method involves the application of a synthetic pheromone that mimics the sex attractant put out by the females to attract a mate. The species-specific pheromone masks the scent of the gypsy moth females, so the males aren't able to find them, thus inhibiting mating. Application is timed just as the adult moths emerge from pupae in late July or early August. While MDA has lead responsibility for gypsy moth treatment, the department works in close partnership with the U.S. Forest Service, the Minnesota Department of Natural Resources, and a host of local and non-profit partners.
More information about MDA 2011 treatments plans
Why Manage Gypsy Moth in Minnesota?
Although gypsy moth will eventually become established in Minnesota, control efforts can minimize and delay the impacts caused by gypsy moth on our forests, save the state millions of dollars in additional control costs, and lost business in recreation and forest industry sectors. Control efforts also slow the spread of gypsy moth to other parts of the state that may be more susceptible to gypsy moth feeding. Currently gypsy moth populations are low in Minnesota and it is important to keep these populations in check. The diligence of the Minnesota Department of Agriculture over the past many years has made possible the eradication of small infestations of gypsy moth, keeping Minnesota essentially free of gypsy moth. The Minnesota Department of Natural Resources supports the Minnesota Department of Agriculture's proposed treatments to delay establishment of gypsy moth in Minnesota as long as reasonably possible.
For more information:
Up-to-date treatment information is available by contacting the Arrest the Pest Hotline at arrest.the.pest@state.mn.us or 888-545-6684.