The Emerald Ash Borer, also referred to as EAB, is fairly new to North America. It was first discovered in Michigan in 2002. In Illinois, it was first discovered in the northern county of Kane in 2006. This beetle is only ½ inch long and 1/8 inch wide; it is metallic green and native to Asia. Its food of choice, as its name denotes, are ash trees.

size of emerald ash borer next to a penny

It is likely that the emerald ash borer was brought to North America unknowingly in ash wood, which is used to make packing crates and for use in cargo ships. They can only fly a half mile at a time from tree to tree, so their spread is slow without the help of humans.

Life Cycle of Emerald Ash Borer

During May to June, the adult emerald ash borer emerges from ash trees and the female will lay multiple eggs in crevices and layers of the ash bark. Seven to ten days later, the eggs hatch into larvae that chew the inner bark and create winding, s-shaped, maze like galleries. These galleries cut the flow of water and other essential nutrients to the tree which will cause significant dieback and eventually death.

The Damage Caused

There are many signs and symptoms to look out for with emerald ash borer. The crown, or top, will have dieback which means the uppermost branches will die. This dieback will get lower and lower each year as the infestation continues to thrive and the tree eventually dies.

Also to look out for is the growth of new branches at the trunk of the tree. These branches are called suckers because they will suck the nutrients out of the trunk before they can ever reach the canopy branches leading to continued dieback to exist in the canopy.

Along the tree trunk there are a few things to watch for such as splitting bark, woodpeckers frequenting a tree, and D-shaped exit holes. When the bark splits it is likely the tree is unhealthy, or in the case of emerald ash borer, being sucked of nutrients. When woodpeckers are frequenting a particular tree, it means they are finding insects to eat within that tree. The D-shaped exit holes may be hard to notice since they are only 1/8 inch in diameter and may mimic those of other borers.

It is unfortunate, but once emerald ash borer is discovered it may already be too late. Damage can happen quickly and take the life of the tree(s) in just a short few years.

Protection and Prevention

New research and treatments are discovered frequently as this pest becomes more of a problem. A new insecticide can be applied to the tree by spraying or injecting to help kill the beetles and larvae present. It is important to remember that a trunk spraying or injection must be done annually during the prime application period to truly be effective.

One of the easiest and most important things to do when it come to stopping the emerald ash borer is to not move wood. Many northern or Midwest states have put quarantines in place meaning no wood can be brought into that are nor can it leave. It is being asked of all citizens to not move firewood either. It is recommended to buy firewood locally to where you want to burn it and not to take any extra firewood home. For professionals, such as suppliers, that wish to move wood from one location to another they are required to register annually with their specific departments, such as the Illinois Departments of Agriculture.

Sum it up

Insects, such as Emerald Ash Borer, can cause substantial damage to trees that you have spent time and money on growing. An infestation can occur quickly and take the life of the even quicker if left untreated.

If you are ever unsure of what to do, how to handle a job, or just too short on time it is best to call a professional to be sure the job is being done correctly. Look around, ask friends or family, and research companies on the Better Business Bureau to find a company that you can trust.

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