MADISON – Emerald ash borer has been confirmed in Marathon County, and the Wisconsin Department of Agriculture, Trade and Consumer Protection (DATCP) will quarantine the county as a result.
A tree care service found infested trees on private property along the Wisconsin River in the Town of Rib Mountain, adjacent to the city of Wausau. Specimens were identified by the U.S. Department of Agriculture Animal and Plant Health Inspection Service Tuesday, Oct. 10.
“Although we have now found EAB in well over half the counties in Wisconsin, much of the area in those counties remains uninfested. Human activity has caused these scattered infestations, not natural spread of the insect. So, it’s still important for people not to move firewood out of infested areas, even within their own quarantined counties,” said Brian Kuhn, director of the Plant Industry Bureau within DATCP. That precaution can delay introduction to new areas of quarantined counties for years.
For private citizens, the quarantine means that they cannot take firewood from quarantined counties to non-quarantined counties. For businesses handling wood products that could carry EAB, it means that they must work with DATCP to assure that their products are pest-free before shipping.
Kuhn recommends that property owners in quarantined counties:
- Watch 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 their property is within 15 miles of a known infestation. Whether to treat depends on several factors: the age of the trees, the size of the trees, and the number of 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.
- Contact 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. Marathon County joins 46 other Wisconsin counties where EAB has been found: Adams, Brown, Buffalo, Calumet, Chippewa, Columbia, Crawford, Dane, Dodge, Door, Douglas, Fond du Lac, Grant, Green, Green Lake, Iowa, Jackson, Jefferson, Juneau, Kenosha, La Crosse, Lafayette, Manitowoc, Marinette, Marquette, Milwaukee, Monroe, Oneida, Outagamie, Ozaukee, Portage, Racine, Richland, Rock, Sauk, Sawyer, Sheboygan, Trempealeau, Vernon, Walworth, Washington, Waukesha, Waupaca, Waushara, Winnebago and Wood. Kewaunee County is also under quarantine because of the proximity of infestations in neighboring counties.