Emerald Ash Borer Infestation Confirmed

The metallic green Emerald Ash Borer has been confirmed on private property on Cottage Row in the Town of Gibraltar.

A certified arborist was doing right-of-way work on Cottage Row south of Fish Creek on May 28 when he saw the tell-tale D-shaped exit holes of the dreaded Emerald Ash Borer (EAB) in ash trees on private property.

His discovery was confirmed as EAB infestation the next day by a Department of Natural Resources forester who was able to collect larvae from ash trees on a nearby property.

“If you’re within 15 miles of the known infestation, you might as well consider yourself infested. It’s going to get to you,” said Donna Gilson of the Wisconsin Department of Agriculture, Trade and Consumer Protection (DATCP), which made the formal announcement of EAB in Door County on June 10 after confirmation of infestation by the U.S. Department of Agriculture.

Door County becomes the 22nd county in the state placed under quarantine since EAB was first detected in Wisconsin in 2008. The quarantine restricts the movement of firewood and ash products.

“Door County has a great deal of tourist traffic, and many cabins and campgrounds, so it is not a surprise to find EAB there. But it’s always disappointing when you find it,” said Brian Kuhn, director of the Bureau of Plant Industry in DATCP. EAB is most commonly introduced to new areas when people bring firewood from infested areas.

For private citizens, this means that neither residents nor tourists may take firewood from Door County to non-quarantine counties.

For businesses handling wood products that could carry EAB, it means they must work with DATCP to assure that their products are pest-free before shipping.

Gilson said DATCP will work with individual businesses that may be affected by the quarantine.

The quarantine 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.

DATCP recommends that property owners who have ash trees:

• 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 Washington County. Other quarantined Wisconsin counties are Brown, Crawford, Dane, Dodge, Douglas, Fond du Lac, Jefferson, Kenosha, La Crosse, Milwaukee, Ozaukee, Racine, 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 eat the wood, 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.