BOSTON — Massachusetts officials said Thursday they have declared the state’s westernmost county a quarantine zone, beginning March 1, to help contain an invasive beetle that’s killed millions of ash trees nationwide.
Beginning next month, no hardwood firewood, ash nursery stock or untreated ash lumber will be allowed outside Berkshire County, where the emerald ash borer was found last summer in trees in Dalton, a few miles from the New York border.
The discovery made Massachusetts the 18th state where the Chinese beetle has appeared since it was detected in Michigan in 2002. Berkshire County also borders Connecticut, where the borer has been found, and Vermont, where it has not.
Massachusetts officials have since tried to determine how to best limit the damage and have held public hearings on the problem. They settled on the countywide quarantine, amid pressure for a measure that would affect as small an area as possible to allow timber businesses to freely move their products throughout Massachusetts. Some wood businesses did push, however, for a statewide quarantine.
“We believe a countywide quarantine will allow the best chance at slowing the spread of emerald ash borer,” said Department of Conservation and Recreation Commissioner Ed Lambert.
Ash trees are about 4 percent of the state’s forests, and 80 percent of the state’s 45 million ash trees are found west of the Connecticut River. It’s used in a variety of products, including baseball bats, railroad ties and picnic tables.
Under the quarantine order, proper wood treatments would include removing the bark plus a half inch of wood, fumigation and dry kiln sterilization. Businesses will still be able to transport wood across the border to mills in New York, which has emerald ash borer quarantines in counties that border Berkshire County. Wood can move between quarantined counties without restriction.
The emerald ash borer is green and so small that seven can fit on the head of a penny. The insect eats only ash trees, with the larvae feeding just below the bark and adults eating the leaves. Once the beetles hit a tree, it’s as good as dead.
The bug’s spread, blamed largely on transported firewood, has included a steady march east, with New York seeing the beetle in 2009 and Connecticut finding it last summer. It has yet to reach the other New England states, but a federal forestry official has said it inevitably will.
The already broad geographic range of the beetle has forced a strategy of containment, since eradication is unrealistic.
In Massachusetts, officials are planning future surveys, as well as attempting to limit the infestation with a process called girdling. The process stresses trees in an attempt to attract and trap any nearby emerald ash borers.