Emerald Ash Borer Confirmed in Green County


Emerald Ash Borer (EAB) has been confirmed for the first time in Green County, in a private yard in the Town of Decatur. The county is already under quarantine for EAB because of quarantines in neighboring counties, so this new find does not change anything from a regulatory standpoint. It should remind county residents of the importance of not moving firewood from the county to non-quarantine counties, officials say.

“We quarantine Green County last July, along with Richland, Iowa and Lafayette counties, even though we had not confirmed findings of EAB there” said Brian Kuhn, director of the Bureau of Plant Industry in the Wisconsin Department of Agriculture, Trade and Consumer Protection. “This block of counties was surrounded at that point by quarantined counties, which leads us to suspect that EAB is present in low numbers that are difficult to detect. The Green County find confirms this.”

A private homeowner in the Town of Decatur notified the Wisconsin Department of Natural Resources after seeing woodpecker damage and the telltale serpentine tunneling made by EAB larvae under the tree bark. Woodpeckers tear bark from infected trees as they feed on the larvae. Samples of EAB larvae were collected April 22 and the U.S. Department of Agriculture confirmed April 24, that they were emerald ash borer.

Quarantines prohibit ash wood products and hardwood firewood from being moved to areas that are not quarantined. For businesses handling wood products that could carry EAB, this means that they must work with DATCP to assure that their products are pest-free before shipping to non-quarantine counties. For private citizens, a quarantine means that residents may not take firewood from these counties to non-quarantine counties.

“While it is legal to move firewood within the quarantined counties, we strongly discourage it” Kuhn said. “The vast majority of EAB infestations have resulted from the movement of firewood. EAB is one of a number of forest pests and diseases that can easily and invisibly move from one location to another under the bark of firewood. If we could reduce the long distance movement of firewood we would reduce the spread of many invasive forest pests, not just EAB.”

DATCP recommends that property owners who have ash trees in quarantine counties:

  • Keep a close watch for possible signs of EAB infestation: Thinning canopy, D-shaped holes in the bark, cracked bark, branches sprouting low on the trunk, and woodpeckers pulling at bark.
  • Consider preventative treatments if your property is within 15 miles of a known infestation.
  • Consider planting different species of trees that are not susceptible to EAB.
  • Call a professional arborist, 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 Ozaukee County. Other quarantined Wisconsin counties are Adams, Brown, Buffalo, Calumet, Columbia, Crawford, Dane, Dodge, Door Douglas, Fond du Lac, Grant, Iowa, Jefferson, Juneau, Kenosha, Kewaunee, Lacrosse, Lafayette, Manitowoc, Milwaukee, Monroe, Oneida, Outagamie, Ozaukee, Racine, Richland, Rock, Sauk, Sheboygan, Trempealeau, Vernon, Walworth, Washington, Waukesha and Winnebago.

EAB adults lay eggs on the bark of ash trees in mid-to late summer. When the eggs hatch a week or two later, the larvae burrow under the bar for the winter and feed, forming the characteristic S-shaped tunnels and destroying the tree’s ability to take up nutrients and water. In summer, the adults emerge through D-shaped holes in the bark.

The Wisconsin Emerald Ash Borer Program includes DATCP; DNR; UW-Madison, UW-Extension; USDA Forest Service and Animal and Plant Health Inspection Service.

Press Release used courtesy of Wisconsin DATCP.


Additional Resources

Ash Wood Processing for Homeowner
EAB Insecticide Control for Homeowners
EAB Look-A-Likes
EAB Pest Alert USFS
Emerald Ash Borer for Professionals
Is My Ash Tree Worth Treating for Emerald Ash Borer