Spraying is underway today along the north shore of Lake Superior to combat the gypsy moth, a pest that can defoliate large tracts of forest, hitting aspen and oak trees especially hard.
The Minnesota Department of Agriculture is spraying the pesticide BTK on tracts near Lutsen and Tofte. The north shore has been a hot spot in recent years for the moths; which may be coming in with vehicles or firewood, or possibly blowing in from Michigan or Wisconsin.
Spray treatments are conducted by airplanes. BTK has low toxicity to plants and animals other than gypsy moth.
Department spokesman Michael Schommer said the infestations are not hold-overs from previous years.
"Typically, when we do a treatment for an infestation...we go back and do followup trapping to make sure that it was effective," Schommer said. "And those treatments by and large are effective, so I think probably in a lot of cases what we are seeing here are new infestations."
Gypsy moths infest much of the United States east of Minnesota, and are slowly moving toward the state from Wisconsin.
"I think what we're seeing is the eastern portion of the state is the hot spot for gypsy moth," Schommer said. "Certainly the northeast has had a lot of the activity in recent years, but we're also starting to see more infestations in the southeastern corner of the state and also in the Twin Cities."