Michigan's Emerald Ash Borer Task Force - desperate to hold the line against its invasive enemy - will soon purify a six-mile wide swath around the 1.6 million acres-worth of ash trees they've decided to leave for dead.
Portions of Monroe County have been identified as targets for the cleansing.
The emerald ash borer beetle, a native of the Far East whose larvae burrow into ash trees and kill them in as little as one year, was first discovered around Detroit in June, 2002.
The ensuing infestation prompted the Michigan departments of agriculture and natural resources, Michigan State University, and the U.S. Department of Agriculture to form a task force to “detect, contain, and eradicate” the exotic pests.
In July, 2002, the task force quarantined six Michigan counties, including Wayne, Oakland, Macomb, Washtenaw, Livingston, and Monroe, preventing the movement of ash tree wood after signs of the beetle's presence.
Now certain areas within those counties - a “core zone” of infestation containing 6 million ash trees - have been marked as untouchable, beyond rescue.
Cities and townships in Monroe County in the core zone include Ash, Berlin, Carleton, Dundee, Estral Beach, Exeter, Frenchtown, London, Maybee, Milan, and Raisinville.
The emerald ash borer is a half-inch long, dark green beetle that lives for two to four weeks in the summer. When burrowing into a tree, the borer's larvae create a D-shaped, half-centimeter wide hole in the wood. When fully mature, the beetle can fly and feast on a tree's canopy. Once a tree loses one-third of its canopy, officials say it's already too late to save with pesticides.
“We're going to let Mother Nature play her role, and let the beetle eat its way out of house and home,” said Frank Sapio, unit leader of the Michigan natural resources department's forest health division.
It's a sacrifice for the greater good, said Sara Linsmeier-Wurfel, a spokesman for the Michigan Department of Agriculture. “Right now we're fighting to save the 22 million ash trees that remain within the six counties but outside the core zone,” Ms. Linsmeier-Wurfel said.
To make sure all of Michigan's ashes don't turn to dust, the task force intends to cleanse a six-mile wide “firebreak” zone around the core area of all signs of infestation. Since the ash borer is able to fly only 2,970 feet in one season, the task force hopes to blunt the infestation's “leading edge.” They further hope the action will save the 22 million trees remaining in the quarantined counties as well as the 670 million ash trees in the rest of the state.
But they have to move quickly.
“This thing came on really fast,” said Robin Millsap, an information officer at MSU's College of Agriculture and Natural Resources. “In just one year, it spread to six counties before we really figured out how to recognize what was going on.”
Starting tomorrow, 84 task force surveyors in bright green vests and marked cars will be scouring the “firebreak” zone - on public and private property - looking for any signs of infestation.
Where infestations are discovered, trees will be cut down and shipped to one of four disposal sites in Michigan, where they will be chipped and burned.
Cities and townships within the “firebreak zone” in Monroe County include Bedford, Erie, Ida, LaSalle, Luna Pier, Monroe, Petersburg, Summerfield, and Whiteford.
Officials said they could not comment on how many ash trees they will have to cut down to contain the infestation until surveyors complete their sweep of the area, sometime in August.
But Mr. Sapio is certain it will be an “impressively high number.”
“We're talking about containing an area of 2,500 square miles,” Mr. Sapio said. “If it were only, say, 50,000 trees, it wouldn't be a problem.”
The task force has received $14.6 million from the U.S. Department of Agriculture for its containment efforts for this year alone, and expects to receive $350 million to $375 million in the next 12 to 15 years.
In April, the Ohio Department of Agriculture chipped 4,000 ash trees from 23 properties near Whitehorse in Lucas County at a cost of $300,000 in order to contain the emerald ash borer.
Subsequent surveys have found no sign of the beetle in Ohio.