Emerald Ash Borer

What is the Emerald Ash Borer (EAB)?

The Emerald Ash Borer is an introduced insect pest from Asia that feeds on and kills ash trees.  These insects cut off the flow of water and nutrients within the trees by feeding underneath the bark.  All species and sizes of ash trees (genus: Fraxinus) are susceptible, except for the mountain ash (Sorbus spp.) which is not a true ash.  If a tree has become infested with EAB, mortality will result, usually within 2-3 years. 

In North America, the beetle was initially discovered in Michigan and southwest Ontario in 2002, and the first infestations in the City of Toronto were detected in 2007 and in York Region in 2008.  It is estimated that the City of Toronto will lose nearly all of its 860,000 ash trees to EAB -- a number which represents canopy cover over both public and private land in the urban forest. 

In York Region, it is anticipated that most of the estimated 2,800,000 mature ash trees growing in the area (700,000 of which are found in the urban forest, and 2,100,000 in rural woodlands) will become infested and die within the next ten to fifteen years.  

Spotting Ash Trees & EAB

©2017 Creative Commons

Do You Have Ash Trees on Your Property?

This downloadable fact sheet will help you to determine whether or not you have any ash trees on your property:

 

©2017 Emily Peden / LEAF

How do I know if my ash tree is infested?

It is very difficult to detect the presence of EAB in the early stages, as many of the more outwardly visible signs and symptoms appear only after two or more years of infestation. Here's what you can detect:

  • Trees appear to be thinning at the crown, dead branches and yellowing of leaves.
  • Adults emerge from a D-shaped exit hole between mid May and late June.
  • Adults are metallic blue-green.
  • Bodies are narrow and 8.5 to 14 mm long.
  • Larvae are a creamy white colour with a light brown head.

 

*Please note that other insects, diseases, and problems can demonstrate similar signs and symptoms as those depicted in this guide, and thus is it advisable that you contact a certified arborist to confirm whether or not EAB is present in your tree.

Options for My Ash Trees

©2013 Lija Skobe / LEAF

From Tragedy to Triumph: Repurposing Ontario's Ash Trees

In 2002 the Emerald Ash Borer was first discovered in the province of Ontario, an insect that fed on and devoured the ash tree, a native Ontario tree. In spite of efforts, treatment, and management plans by municipalities and conservation authorities, not all trees could be saved and it is expected millions of trees will vanish, forever altering Ontario’s tree canopy.

Partners in Project Green, along with Toronto and Region Conservation, City of Toronto, City of Markham, and the Town of Richmond Hill found a way to re-purpose these trees into valuable wood products, turning an ecological disaster into a success story. Check out their videos to learn more:

 

From Tragedy to Triumph - An Ash Tree Success Story

 

Town of Richmond Hill's Success Story

 

For more information visit Partners in Project Green

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