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Emerald Ash Borer
 Emerald Ash Borer

 July - August, 2006


(photograph courtesy of the USDA)

The emerald ash borer is a serious threat to ash trees in Illinois and much of the U.S. Recently the insect was found in Kane County and Cook County (Evanston and Wilmette).

The emerald ash borer was an accidental import from Asia. It was first discovered in Michigan in 2002, where it has so far destroyed 15-17 million trees. It has spread rapidly throughout the Midwest and much of the U.S. It feeds primarily on ash trees, which account for about 2% of the U.S. total leaf cover, and about 14% of Chicago’s leaf cover. There are about 178 million ash trees in Illinois.

Adult insects are bright metallic green (males) or bronze colored (females), about a half inch long. They are able to fly up to about six miles. Eggs are deposited in crevices of tree bark. The adults leave a small D-shaped exit hole as they exit the tree in late June or July. Woodpeckers eat the larvae, and heavy woodpecker damage on trees may indicate larvae infestation.

If you suspect infestation, call the US Department of Agriculture at 866-322-4512, the Illinois Department of Agriculture at 847-294-4343, or the US Department of Agriculture in Chicago at 312-742-3385.

For more information, visit the Emerald Ash Borer web site or the Illinois Quarantine Site.

© Riverwoods Preservation Council- - Page last updated: December 2009