The emerald ash borer has been detected for the first time in Waukesha County.
Wisconsin agriculture officials said Thursday that invasive pest was found in Mukwonago. An arborist working for the village notified state officials, and results were confirmed Wednesday.
The emerald ash border is responsible for the death of tens of millions of ash trees in the eastern United States.
Emerald ash borer has now been discovered in 11 Wisconsin counties: Brown, Crawford, Fond du Lac, Kenosha, La Crosse, Milwaukee, Ozaukee, Racine, Sheboygan, Vernon and Washington.