News Releases


Emerald Ash Borer Found in Jefferson County; No Change in Quarantine Status
May 2, 2014

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Contact:   Donna Gilson, 608-224-5130,
               Jim Dick, Communications Director, 608-224-5020,

MADISON – Emerald ash borer has been confirmed for the first time in Jefferson County.

Although EAB had not previously been found in Jefferson County, the county has been under quarantine for EAB since July 2013, when an infestation was found in Whitewater. The city straddles Walworth and Jefferson counties. The infestation was in the part of the city that lies in Walworth County, but was just hundreds of feet from Jefferson County.

“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.”

A forester employed by the Wisconsin Department of Natural Resources found the insects while conducting surveys for woodpecker damage at a boat landing in Prince’s Point State Wildlife Area three miles northeast of Whitewater. Woodpecker damage is one possible indicator of EAB infestation, because the birds feed on the immature insects overwintering under tree bark. The U.S. Department of Agriculture confirmed that the insect samples were EAB. About a dozen trees had obvious damage.

For private citizens, the quarantine means that they cannot take firewood from Jefferson 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.

EAB has now been found in 20 Wisconsin counties:  Brown, Crawford, Dane, Dodge, Douglas, Fond du Lac, Jefferson, Kenosha, La Crosse, Milwaukee, Ozaukee, Racine, Rock, Sauk, Trempealeau, Vernon, Walworth, Washington, Waukesha and Winnebago. All are under quarantine. Sheboygan County is also under quarantine because of nearby infestations in neighboring counties.

For property owners in Jefferson 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 for detailed information.


Kuhn also asked property owners in non-quarantine counties to report signs of EAB infestations. For pictures of EAB and its damage, and to report suspected infestations in non-quarantine counties, visit It is not necessary to report infestations in counties that are already under quarantine.

Emerald ash borer is native to China and entered the United States about 10 years ago on packing material, showing up first in Michigan. It appeared in Wisconsin in 2008 in Washington County.

EAB adults lay eggs on the bark of ash trees in mid- to late summer. When the eggs hatch, the larvae burrow under the bark for the winter and eat the wood, destroying the tree's ability to take up nutrients and water. In summer, the adults emerge through D-shaped holes in the bark. On their own, they may spread about a half mile per year.