What Is Wrong With My Ash Tree? Emerald Ash Borer

Emerald Ash Borer Is An Invasive Pest

The Emerald Ash Borer (EAB) is an invasive species of beetle that hitched a ride to the United States in 2002 and began its invasive march near Detroit Michigan. EAB has become the single most destructive invasive pest in history killing millions of ash trees and creating tremendous risk and expense for homeowners, property managers, and cities.

EABAdults typically emerge in mid- to late-May with peak emergence in late June. Adult females will lay eggs in bark crevices after emerging. After the eggs hatch, the larvae bore through the tree and begin to feed on tissue just under the bark. This part of tree carries water and nutrients from the soil up into the tree. The damage caused by just a few of these hungry larvae will cut off the flow of water and kills the tree if left uncontrolled. Dead trees become extremely brittle and create risk for people and other nearby targets.

Adult emerald ash borers have a body that is dark metallic green in color and ½ inch long with flattened backs. While they are only visible for a short time in the spring, they are easy to spot. Larva are creamy white and legless with flattened, bell-shaped body segments. They are tough to spot unless bark is peeled away from the tree.

What Are The Symptoms Of Emerald Ash Borer?

Signs and symptoms of emerald ash borer include:

  • Canopy dieback
  • Increased woodpecker activity
  • S-shaped larval galleries visible just under the bark
  • Splitting bark
  • D-shaped exit holes in the bark
  • Presence of larvae and adults
  • Epicormic shoots (sprouts growing from the trunk)

Managing Emerald Ash Borer In Your Trees

Our region has been dealing with EAB since 2012 and it has killed tens of thousands of ash here. Experience from hundreds of other US cities reveals that all untreated ash trees will be killed by this destructive pest. The good news is that the borer can be prevented from attacking ash trees. If you value your ash tree and don’t want to suffer the expense of removal, prevention is the best option. Injections applied to the base of the tree are very effective at preventing emerald ash borer attacks. Treatments are typically required every two years.  While costly, they can keep your tree alive so you can enjoy the benefits it provides.

If the tree is already infested, and the canopy dieback is far enough along, you may want to consider removing the tree to prevent further spread of the beetle. Hansen’s ISA-Certified Arborists can provide an estimate of the cost to remove your ash tree and assist with recommendations for replacement plantings. Our ISA Certified Arborists can also help provide information that will help you make that tough decision… treat or remove.  Doing nothing will cause inevitable results. No one wants to deal with a tree that creates high risk.

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