The Tale of the Emerald Ash Borer

In 2002, the Emerald Ash Borer packed its bags and left its native China, hitching a ride in some solid wood packing material bound for Michigan.  It liked it here and decided to make the US its home, consequently expanding its family throughout the country.  While this sounds like a happy slice of life story, it is not.  It is a horror story of a monster that leaves death and destruction in its wake.  

Since its arrival, the Emerald Ash Borer, or EAB, is responsible for the death of hundreds of millions of ash trees in North America, has cost cities and towns, property owners, nurseries, and forest industries hundreds of millions of dollars, and has caused the USDA to enforce quarantines where infestations are high.  The loss of ash trees, especially in areas where they are the predominant species, can cause a detrimental effect on species that rely on the trees for habitats.  

What is the Emerald Ash Borer?

The EAB is a beetle that only attacks ash trees.  It’s about a ½ inch long and has a metallic green shell.  Their eggs are extremely small, approximately a 25th of an inch, and are reddish brown in color.  In their larval state, they are white, flat-headed and segmented, with brown pincers on the last segment.

They have a one or two-year life cycle.  In mid-to-late May, they begin to emerge from ash trees and within two weeks, the adults will fly up to half a mile from where they emerged to lay their eggs on a new ash tree.  The eggs hatch in two weeks and the larvae begin to bore into the tree, settling into the area just under the bark where the nutrients are richest, where they will continue to make bore trails and growing to 1 ½ inches in length.  The larvae will winter in the tree, and emerge in beetle form in the spring.    

The Problem.

The EAB is considered to be the most destructive pest ever seen in North America.  The adults will eat the foliage of the ash tree, but it does little damage.  The real damage comes from the larvae.  While they feed on the wood, they wiggle back and forth, making distinct S-shaped patterns under the bark.  This interrupts the tree’s ability to get water and nutrients to the areas above the infestation, and it will begin to die.  Small trees will die within 2 years and larger ones will most likely die within 4 years.  They’ve been found in trees as small as 1” in diameter.

Besides ecological problems, the loss of ash trees is a real problem for commercial property owners as well.  Trees not only make your campus a beautiful place to work or visit, they also cut down on cooling costs by making the area up to cooler, according to the US Department of Energy.  They cut the harsh sun’s rays while letting cool breezes in, and they also important in fighting soil erosion, increases property value, and one mature tree can absorb 48 pounds of carbon dioxide per year.

The Solution.

With diligence, there is hope in fighting the EAB and having a happy ending to the story of our ash trees.  A big reason for their expanding territory is due to humans transporting them in wood, whether it’s lumber, buying infected trees at nurseries, or in firewood.  If you buy firewood, only buy it from a local source, kiln-dried is best, and never transport firewood across state lines.

Monitor your ash trees!  Here’s what to look for:

  • D-shaped exit holes about ⅛” in diameter on the bark of your ash trees.
  • Dieback at the tops of your ash trees.  Because nutrients can’t get to them, the tops tend to die off first.
  • Abnormal amounts of woodpecker holes.  Woodpeckers love to feast on EAB larvae so increased woodpecker activity on ash trees is a good indication that you have an infestation.
  • S-shaped boring patterns beneath the bark.

If you find any EAB beetles or any of the indicators listed above, call the Emerald Ash Borer Hotline at (866)322-4512 or your local USDA Animal and Plant Health Inspection Service Office.  Record the areas where you’ve found the insects and take pictures of them along with the damage.

Then call us.  The tree experts at Bluegrass Landscaping and Maintenance can remove the infected tree quickly, hopefully before the infestation has spread to other ash trees on your property.  We can then replace it with another type of tree, one that the EAB wouldn’t want to call home.  

With some close attention, you can keep your ash trees healthy and free from the scourge of the EAB and do your part in keeping it from spreading further.  Call Bluegrass today at (314) 770-2828.