Emerald ash borer and the ash trees in your yard

The emerald ash borer is an invasive wood-boring beetle from Asia, first found in North America in southeast Michigan in 2002. It has killed or weakened tens of millions of ash trees and is now in 38 states and the District of Columbia. The beetle flies well and spreads on its own. It travels long distances when people move infested ash firewood, logs or nursery stock.

The signs in an ash tree

The adult beetle is metallic green with a coppery-red abdomen and about half an inch long. The tree shows the damage.

• Dead branches near the top of the tree
• D-shaped exit holes in the bark, left by the adults
• S-shaped markings under the bark, left by the larvae
• Vertical cracks in the bark
• Excess branching on the trunk
• More woodpecker activity than usual

Firewood and the pests that ride along

Infested ash firewood is one of the ways emerald ash borer moves long distances. Get firewood from near where you'll burn it, or use wood certified as heat-treated. The same goes for the wood for a camping trip or a cabin stove.

How it's being controlled

Federal plant health programs rear and release stingless wasps to manage the beetle. For a single tree in a yard, treatments exist, and the local Cooperative Extension office can advise whether treating a particular ash makes sense.

An annotated example

What to do next

Look over each ash tree once a year while it's in leaf. For a tree with the signs, call the local Cooperative Extension office, which can advise whether treating the tree makes sense. Report a suspected infestation, especially in an area where it hasn't been found, at 1-866-322-4512.