The ecological history of the U.S. has been dotted with epidemics destroying large segments of the populations of certain tree species. Currently, ash trees are under threat of decimation, thanks to the arrival of the emerald ash borer, first discovered in southeastern Michigan in 2002. Thought to have come on a shipment of ash wood from a foreign country, emerald ash borers are rapidly infecting millions of ash trees across the U.S.

What Are Emerald Ash Borers?

Emerald ash borers are dark metallic green insects with coppery red or purple abdomens beneath their wings. They feed on the inner bark of ash trees, keeping the tree from transporting the necessary water and nutrients for its survival.

Where Do They Come From?

Now that they’ve made their way to the continent, emerald ash borers travel mainly through the transport of ash firewood or nursery stock. For this reason, it is recommended that firewood is purchased or cut from the same general location where it is intended for use.

How Can I Recognize Ash Tree Disease?

There are a few major indicators of ash tree disease brought about by emerald ash borer infestation.

1. Thinning of the canopy. Because the emerald ash borer keeps trees from transporting nutrients the parts of the tree furthest from the roots tend to be undernourished.
2. Epicormic sprouting. When the tree begins to notice that it’s in trouble, it will begin trying to start new growth at any possible location. Branches sprouting from the base or the trunk are signs of ash tree disease.
3. D shaped exit holes throughout the bark. Emerald ash borers leave such exit holes throughout the tree and leave S shaped galleries below the bark.
4. Woodpecker holes are left by birds going after emerald ash borer larvae.

Unfortunately, other types of ash tree disease also have similar symptoms, making it hard for homeowners to distinguish between an emerald ash borer infestation and other diseases like verticillium wilt and fungal cankers.

Can the Emerald Ash Borer Be Controlled?

Emerald ash borer control is possible if homeowners are quick to recognize and contact a licensed arborist who can diagnose and treat the infected tree. Emerald ash borer treatments are high level pesticides that must be administered multiple times. They are not always successful, and for that reason many homeowners elect to dispose of their infected ash trees.

It should be emphasized that only licensed arborists are qualified to administer emerald ash borer treatment that can eradicate ash tree disease. If you think your tree or a public tree might be infected, make the call. It’s better to find out that the tree has something else than to let an infestation go unchecked.