MADISON, Wis. (WISCONSIN DATCP NEWS RELEASE) -- Emerald ash borer has been confirmed in Adams County for the first time, triggering a quarantine in that county and in neighboring Juneau County. Buffalo County will also be quarantined, because an EAB infestation has been found at Merrick State Park. This brings the total number of Wisconsin counties under quarantine to 32.
An adult EAB beetle was found in one of the familiar purple traps July 22 in the Town of Monroe in Adams County, along Lake Petenwell, which is the border between Adams and Juneau counties. Juneau County is now surrounded on three sides by counties where EAB has been confirmed, and it is highly likely that the pest is also present there, says Brian Kuhn, director of the Bureau of Plant Industry in the Wisconsin Department of Agriculture, Trade and Consumer Protection.
“Low-level EAB infestations often go undetected for several years,” Kuhn said. “This new find is within two miles of Juneau County, and EAB can spread up to two miles a year on its own, even without help from humans. If EAB is not already in Juneau County, it likely will be soon.”
In Buffalo County, an adult beetle was found in a purple trap placed between the boat landing and the nature center in the state park. The trap was placed near ash trees showing signs of infestation.
The quarantines will be put in place temporarily by a Wisconsin emergency rule, until the U.S. Department of Agriculture completes the process to enact a federal quarantine. The quarantines will apply to the entire counties.
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 neither residents nor tourists may take firewood from these counties to non-quarantine counties.
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 preventive 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 about 10 years ago. It was first found in Wisconsin in 2008 in Ozaukee County. Other quarantined Wisconsin counties are Brown, Columbia, Crawford, Dane, Dodge, Door, Douglas, Fond du Lac, Grant, Green, Iowa, Jefferson, Kenosha, La Crosse, Lafayette, Milwaukee, Monroe, 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 bark 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.