Emerald Ash Borer

The Emerald Ash Borer (EAB)

Invasive Wood Boring Beetle

The Emerald Ash Borer is an invasive boring beetle that feeds on the inner living tissues of the tree that are responsible for transporting water and nutrients, which basically suffoctes and strangles the tree to death within a 2 - 5 year period of time.

This metallic wood boring beetle was found in Detroit, Michigan and Ontario, Canada in 2002, and has now been identified spreading throughout the United States with heavy concentrations currently in Illinois, Indiana, and Ohio. This epidemic is being compared to the Dutch Elm disease of the past. However we are more capable of containing and limiting the damage caused as long as you act now with either treatment or removal of affected Ash trees.

How the Emerald Ash Borer Kills Your Trees

Typically in the months of May & June, the adult EAB fly and spread to Ash trees in the area, mate and lay 70 – 90 eggs each. The eggs hatch within a week and 70 – 90 tiny Emerald Ash Borer larvae bore their way through the bark into the living vascular tissues of the tree. As larvae, the entry holes they make are tiny and almost impossible to see, which is what makes it so difficult to diagnose whether your tree has been infested or not.

The larvae continue to feed on the living vascular tissues of your tree late spring, summer and fall for their nutrition. Unfortunately for your Ash tree, those tissues that the EAB are eating, are the same tissues the tree needs to carry the nutrients and minerals from its roots to feed and keep its canopy healthy.

So, you can see, as the borers eat the vascular tissues of the tree, branches and leaves can no longer receive the nutrition they need to live and be productive and they begin to die back. Typically from the top and tips of branches, because they are the furthest from the source of nutrition and thus the first to go.

The tricky thing particularily about EAB is that is nearly impossible to diagnose whether your tree has the bug or not. When winter comes and the tree goes into a dormant/hibernation like stage, so do the mostly grown EAB larvae. They stop where they were eating, in their tunnel in the vascular tissue and chill for the Winter.

When the tree begins to be active, usually late February or early March, the EAB enters its’ pupae stage and continues feeding, growing, destroying more precious vascular tissue, and becoming an Adult beetle. The adult beetles bore their way out of the tree, fly high into the Ash tree tops, mate, lay their 70 – 90 eggs and the cycle multiplies.

Sometimes sprouts(baby trees) begin emerging from the trunk as well as often, the woodpeckers will become more active in your tree as they feed on EAB larvae. But for the most part, even for the professional, it is very challenging to know whether your tree is infested or not. and by the time the signs become clear that your trees are infested, usually the borers have already caused detrimental damage to your tree.

So the universal suggestion: Treat every tree that you want to remain healthy and alive, and to remove all of the ones that you do not.

Emerald Ash Borer - Life Cycle

May/June Adults bore out of tree, mate, lay 70-90 eggs, and die; Eggs hatch in 1 week, Larvae bore into the living tissues of the tree where they feed up until Winter by chewing s-shaped tunnels beneath the bark. Dormant through the winter. Begin feeding again early Spring until strong/developed enough to emerge as adults in May/June.

ash trees full grown