A Basic Guide To Emerald Ash Borer Infestations

Posted on: 21 May 2020

Emerald ash borers came to the US from Asia in the early part of the the new millennium. Since their arrival, these wood-boring insects have left behind a path of devastation across the US, killing millions of ash trees and infesting many more. Understanding the life cycle of the pest as well as proper treatment and control is vitally important if you have ash trees on your property.

Ash Borer Lifecycle

These small emerald green beetles emerge as flying insects in the spring to begin their adult lifecycle. They spend the summer mating, and then they lay their eggs beneath the bark of an ash tree. The larvae develop under the bark feasting on the wood of the ash tree. Eventually, the pressure from many feeding larvae kills the tree. In the spring, the larvae then emerge as adults and the cycle starts all over again.

Signs of Infestation

The earliest signs of an infestation are easy to miss. Branches at the top of the canopy tend to become brittle and break off, or visible cracks may begin forming on lower branches. As an infestation progresses the symptoms become more pronounced. Thin vertical slits on the bark, increased woodpecker feeding activity on the tree, and D-shaped holes on the trunk are the most obvious signs. The leaves may also become ragged from feeding adult borers. Further, you may notice S-shaped tunnels on the trunk where ever the bark happens to break off.

Ash Borer Prevention and Treatment

Prevention is difficult. If the ash borers are not yet in your area, the best form of prevention is frequently assessing of your trees for any signs of infestation. If you catch an infestation early, you can have the tree treated with a systematic pesticide formulated to kill ash borers and other boring beetles. Treatment should begin as soon as ash borers are found in your area, even if you haven't seen immediate signs of infestation on your trees. Your trees will need to be treated annually to keep the pests away. Keep in mind that once ash borers find a tree, treatment is not always successful. If the infestation becomes severe, it is better to remove the tree to reduce the risk to neighboring trees.

Healthy trees are more likely to resist infestation or at least survive it with treatment. This means proper pruning, regular watering, and sufficient fertilization. Avoid anything that would put additional stress on at-risk ash trees. Contact a tree care service for more assistance with emerald ash borer treatment or prevention.


Keeping Your Trees Healthy

About a year ago, I realized that our front trees were starting to look a little funny. Some of the leaves were wilted, but we weren't anywhere near autumn. The bark on the trunk also seemed to be rotting away, which was frustrating and disappointing. Fortunately, a friend of mine told me to call a professional arborist for help. He came out, inspected the trees, and injected some special pesticides into the trunk. Within a few months, they started to look a lot better. Our arborist also trimmed our trees to reduce the weight load on the branches and to improve their shape. Check out this blog for information about tree trimming.