MADISON, WI (WTAQ) - Almost a third of Wisconsin counties are now under quarantine for the tree killing emerald ash borer.
Dane County became the 21st such county Tuesday, after a tree contractor found evidence of the invasive beetle in its larval stage under the bark of ash trees at a park in Madison.
The U.S. Agriculture Department confirmed the ash borer's presence last Friday.
All of Dane County is under the quarantine, joining the adjacent Rock, Jefferson, Dodge, and Sauk counties. Businesses that handle ash products must certify with the state that they're disease free.
Also, Dane County firewood cannot be transported to counties without quarantines.
Brian Kuhn of the state Agriculture Department says his agency is disappointed with the latest finding -- but it's not surprised, given the earlier presence of the emerald ash borer in southern Wisconsin and the ease of transporting infected beetles.