Emerald ash borer reaches every county in Wisconsin

The Wisconsin DNR confirms the detection of emerald ash borer (EAB) in Burnett County, which means the pest has now been confirmed in all 72 of Wisconsin’s counties. The state’s first confirmed sighting of EAB took place in Ozaukee County, in July 2008. Although the ash tree-killing beetle is less established in northwest Wisconsin, than in other parts of the state, this year’s detections indicate that the pest is expanding its foothold in the region. EAB is usually transported to new areas, by hitching a ride on firewood. EAB larvae bore into ash trees and carve winding, S-shaped galleries beneath the trees’ bark, typically starting in the upper canopy and progressing down the tree. The galleries restrict the movement of water and nutrients to affected areas of the tree, leading to branch dieback, canopy thinning and tree death. EAB is expected to eventually kill more than 99 percent of Wisconsin’s white, black and green ash (and their ornamental varieties). Landowners concerned about EAB should contact a forestry professional or ISA-certified arborist, and consult the state’s EAB Information Resource webpage, at datcpservices.wisconsin.gov, to learn about management options. In the parts of northern Wisconsin, where EAB populations remain low, there is still an opportunity to reduce the insects’ impact.