EAB found in Sawyer County; quarantine in process

Wisconsin State Farmer


In this June 22, 2011 file photo are tracks from emerald ash borers left in a black ash tree outside the Riveredge Nature Center in Newburg.

Emerald ash borer has been found in Sawyer County, the second most northern location in Wisconsin to date. The county will be quarantined.

"This new infestation is concerning, because it's getting to our North Woods, less than 20 miles from the Chequamegon National Forest and the adjoining Flambeau River State Forest. But it's not surprising, given the ease with which this pest can hitchhike with the help of humans," said Brian Kuhn, director of the Bureau of Plant Industry in the Wisconsin Department of Agriculture, Trade and Consumer Protection. "Fortunately, the infestation appears to be in a very early stage, with no damage apparent yet, and even though it's in a heavily wooded area, very few of the trees are ash."

Only ash trees are susceptible to the destructive beetle.

A single adult beetle was found in a monitoring trap set by the U.S. Department of Agriculture Animal and Plant Health Inspection Service as part of its national survey for EAB. The trap was set along North Eastlund Road in the Town of Radisson.

The quarantine will apply to all of Sawyer County. It prohibits ash wood products and hardwood firewood from being moved out of the county to areas that are not infested. For private citizens, this means that they cannot take firewood from Sawyer County to non-quarantine counties. For businesses handling wood products that could carry EAB, it means that they must work with DATCP or the USDA to assure that their products are pest-free before shipping.

DATCP recommends that property owners who have ash trees in quarantine counties do the following:

  • Keep a close watch on ash trees for signs of possible EAB infestation: Thinning in the canopy, D-shaped holes in the bark, new branches sprouting low on the trunk, cracked bark, and woodpeckers pulling at the bark to get to insect larvae beneath it.
  • Consider preventive treatments if your property is within 15 miles of a known infestation. Whether to treat depends on the age, size and number of ash trees. Treatment costs vary depending on size of the tree and whether you do the treatments yourself or hire a professional.
  • Consider planting different species of trees that are not susceptible to EAB.
  • Call a professional arborist for expert advice, and visit emeraldashborer.wi.gov for detailed information. 

Emerald ash borer is native to China and probably entered the United States on packing material, showing up first in Michigan in 2002. It was first found in Wisconsin in 2008 in Washington County. Sawyer County will join 38 other Wisconsin counties where EAB has been found: Adams, Brown, Buffalo, Calumet, Columbia, Crawford, Dane, Dodge, Door, Douglas, Fond du Lac, Grant, Green, Jackson, Jefferson, Juneau, Kenosha, La Crosse, Lafayette, Marquette, Milwaukee, Monroe, Oneida, Outagamie, Ozaukee, Portage, Racine, Richland, Rock, Sauk, Sheboygan, Trempealeau, Vernon, Walworth, Washington, Waukesha, Winnebago and Wood. Iowa, Kewaunee and Manitowoc counties are also under quarantine because of the proximity of infestations in neighboring counties.