Emerald ash borer has been confirmed for the first time in Manitowoc County, in a private woodlot in the Town of Schleswig.
Although EAB had not previously been found in Manitowoc County, the county has been under quarantine for EAB since 2014, when infestations were found in neighboring Calumet and Outagamie counties.
“This will not change anything from a regulatory standpoint,” said Brian Kuhn, Plant Industry Bureau Director with the Wisconsin Department of Agriculture, Trade and Consumer Protection (DATCP). "The quarantine will remain in place. The insects will continue to spread naturally, but the quarantine can help prevent EAB from leapfrogging to entirely new areas with the help of humans.”
The property owner noticed woodpecker damage to ash trees throughout a six-acre woodlot and reported it to the state EAB hotline. DATCP staff visited the site Oct. 6 and collected EAB larvae, or immature insects, from two heavily infested trees. Samples went to the U.S. Department of Agriculture for official confirmation, which was received October 12.
For private citizens, the quarantine means that they cannot take firewood from Manitowoc County to non-quarantine 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.
For property owners in Manitowoc County and other quarantine counties, Kuhn recommended:
- 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.
- If your property is within 15 miles of a known infestation, consider preventive treatments. 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.
Manitowoc County joins 39 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, Sawyer, Sheboygan, Trempealeau, Vernon, Walworth, Washington, Waukesha, Winnebago and Wood.
Iowa and Kewaunee counties are also under quarantine because of the proximity of infestations in neighboring counties.