Spongy moth quarantine to go into effect for three cities to prevent damage to forests
Residents of Grand Rapids, Coon Rapids and Winona will not be able to move wooded material — including firewood — out of the area due to an infestation of spongy moths.
"Spongy moths are a big pest," said Mark Abrahamson with the Minnesota Department of Agriculture. "They are prolific defoliators, so they eat a lot of leaves. They can be broad in terms of their host distribution."
Minnesota Department of Agriculture officials say the moths have caused millions of dollars of damage to forests across the eastern United States. In order to mitigate any potential damage, officials are asking residents to quarantine their woody material from May 1 to June 15 of 2026.
"The quarantine is an informational tool to tell people, there's this thing here we are trying to keep in place and we can come and treat it next year," Abrahamson said.
The three areas were scheduled to be aerially managed this spring with an insecticide used to kill spongy moth caterpillars, but federal funding delays and uncertainties forced the department of agriculture to pivot, officials say.
"We were unable to do the treatments we had planned in a few cities.and with it being cities with people, there's a risk of moving the spongy moth out of those areas," Abrahamson said.
The quarantine restricts the movement of trees, branches and woody material out of the area. Trees can be pruned, but the branches must stay on the property, officials say. The department also is asking residents to inspect any outdoor items like wood pallets, patio furniture, grills and campers for spongy moth egg masses.
"If you are going to be moving things outside out of the area, you could just take a quick check," Abrahamson said.
The infestations were discovered in Coon Rapids and Grand Rapids during a spongy moth survey last year, the agriculture department says. In Winona, employees at a city campground reported the moths to the department.
According to the Minnesota Department of Natural Resources, the spongy moth is an invasive pest that feeds on over 300 different species of trees and shrubs. They were first introduced in in Massachusetts and have since made their way west, as caterpillars defoliate large sections of urban and natural forests. A spongy moth quarantine is already in effect in Lake and Cook counties.
Minnesota's participation in the national "Slow the Spread" program, a collaborative effort of 10 other states, has helped reduce the spread of spongy moths. Aerial Btk treatments have proved to be effective.
Nicholas Ostby, a tree service expert and owner of N E Services 365 in Coon Rapids, said they are ready to make adjustments.
"This is going to be a new experience for us," Ostby said. "That may be harder on the workload to have to go through all the wood to do that. Which is going to cost time and money. But we will do what we have to do to stay in compliance."
Residents in quarantine areas and the general public are invited to attend an information meeting. They will host a virtual meeting on Tuesay from 12 to 1 p.m., and will also hold an open house on Wednesday from 4:30 to 6:40 p.m. at the Sand Creek Community Board Room in Coon Rapids.
For more information about the quarantine, you can find maps and information here.
