Emerald Ash Borer

Emerald ash borer

How much wood can a bug eat, if a bug could eat wood?

Answer:  A lot!

The culprit:   The Emerald Ash Borer is an Asian Beetle that infests, attacks and kills all species of North American Ash trees.  They most likely came to the states in shipping palettes from Asia and were first discovered in 2002. Now, more than 10 years later, our forests are severely threatened.  The white larvae live under the bark of the tree and then emerge into a dark green adult with metallic coloring.

If you have Ash trees in your yard, you must be very vigilant in watching for the Emerald Ash Borer. It is important to understand the signs.

Emerald Ash Borer
Emerald Ash Borer larva next to nickel

The canopy of infested trees begins to thin above infested portions of the trunk and major branches because the borer destroys the water and nutrient conducting tissues under the bark. Heavily infested trees exhibit canopy die-back usually starting at the top of the tree. One-third to one-half of the branches may die in one year. Most of the canopy will be dead within 2 years of when symptoms are first observed.


Sometimes ash trees push out sprouts from the trunk after the upper portions of the tree dies.

Difficult to see, the adult beetles leave a “D”-shaped exit hole in the bark, roughly 1/8 inch in diameter, when they emerge in June.

If you see any of these signs, it is important to call in an expert to determine the next step.  Grasshopper Gardens uses the Arbor Jet System to treat Ash Trees.  It is best to treat before the borers have infested the tree.  It is more cost effective to treat the tree rather than cutting it down and replacing it.  Once the tree is infested, it can be treated, depending on the level of infestation.