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Simcoe County > Departments > Forestry > Emerald Ash Borer

Emerald Ash Borer

The Emerald Ash Borer (EAB) in an invasive insect originating from Asia.  It was first discovered in North America in the Detroit and Windsor area in 2002.  The insect attacks and kills ash trees (only true ash or fraxinus species, it does not affect Mountain-Ash or sorbus species).  Since its introduction it has been spreading throughout southern and central Ontario, Quebec and many states within the US causing the death of millions of trees.

The pest was first discovered in southern Simcoe County in 2013.  By 2016 it has been found in over half of the local municipalities within the County.   

What does it do?

The larvae of the Emerald Ash Borer feed on the living tissue below the bark of an ash tree called the cambium.  These feeding galleries disrupt the flow of nutrients and water within the tree causing crown die back, epicormic shoots, peeling bark and death in sometimes as little as 1-2 years.  The insect attacks and kills trees of all sizes and ages and kills greater than 99% of trees which it infects.

Pest Biology and IdentificationEmerald Ash Borer

The Emerald Ash borer is a wood boring beetle that is 8-14mm long (5/16" to 9/16 ").  It is bright metallic green with a coppery-reddish or purple colour to the abdomen. 

Adult beetles emerge from under the bark of ash trees from May to August.  After emergence the adults feed for approximately one week thenMarking in wood from emerald ash borer commence mating.  A female then lays 40-70 very small eggs in a crevice or fold in the bark of an ash tree.  The eggs hatch within 2 weeks and the new larvae bore into the tree where they feed on the cambium (living tissue underneath the bark).  The larvae feed under the bark producing serpentine or S-shaped feeding galleries until fall.  They then excavate a chamber in the bark or sapwood where they overwinter.  The larvae then pupate and emerge as adults the following spring by burrowing out of the tree and through the bark, leaving a distinct D-shaped exit hole.

Privately Owned Trees: What Can I do?    

It is the responsibility of the landowner to manage or remove trees on their own property. 

Most landowners will have two choices when considering the future of an Ash tree.  The tree can be given protection against the insect by treating with an insecticide.  Otherwise most trees not protected will eventually die and should be removed. treeazin helping save tree

There are several products available to treat ash trees and increase survival.  TreeAzin is injected by a licensed applicator into the base of the tree on a 2 year cycle (annually in some cases) and can provide protection against tree mortality from the insect.  The pesticide is only effective on trees that are not yet infected or at early stages of infection from EAB.  Treating trees with an insecticide can be a financially sound option for many landowners.  This will help maintain important landscape trees especially when considering the added values of these trees including aesthetics, home heating and cooling, land value appreciation and privacy.

If trees are not treated to protect against infestation from the insect they can die fast and become a safety hazard.  If you think your tree is infected or would like to have it removed contact an ISA Certified Arborist to discuss treatment or removal options.  Removing a tree before it becomes weak and dangerous is recommended for both safety and financial reasons.

See the links below for further information:

How do I identify an ash tree?

Signs a tree is infested

List of Certified Arborists

TreeAzin Insecticide

Hiring a Tree Care Professional

Woodlot Owners or Landowners of Larger Properties

Owners or managers of privately owned woodlands and larger properties containing ash trees are encouraged to contact a forestry professional to offer advice to mitigate damage and reduce financial and ecological losses.  There are many sound management strategies to mitigate the impact of the Emerald Ash Borer.

Preparing for Emerald Ash Borer - A Landowners Guide

Finding a Forestry Professional

Regulation and Disposal of Ash Materials

Since the confirmation of Emerald Ash Borer within the County of Simcoe, the area has come under ministerial orders from the Canadian Food Inspection Agency regarding the movement of certain woody materials.

There are prohibitions and regulations restricting the movement of nursery stock, trees, logs, lumber, leaves, bark chips and wood chips of all ash species and regulations that restrict the movement of ALL firewood species. 

Regulated materials may not be moved out of a regulated area into a non-regulated area without a movement certificate issued by the Canadian Food Inspection Agency.

Why should I buy and burn firewood locally?

Emerald Ash Borer Regulated Area

What is The County of Simcoe Doing?

The County of Simcoe owns and manages over 32,000 acres of forest.  Since the mid 2000's forest managers have closely monitored the progression of the Emerald Ash Borer throughout Ontario.  When it became apparent that the insect would eventually spread into Simcoe County, forest management activities were modified to mitigate the loss of this tree species from the Simcoe County Forest landscape. 

An Emerald Ash Borer monitoring program had been conducted within the County by the Canadian Food Inspection Agency (CFIA) since the mid 2000's.  With the discovery of the insect in Bradford in 2013 and with the newly formed regulated area, the CFIA monitoring program had ceased in Simcoe as of that year.  The County now administers its own monitoring program.  This enables the continued monitoring of this pest throughout the local towns and townships within the County of Simcoe to assist with management activities.

A strategic plan has been prepared and approved by council in 2014 to provide information and options for Emerald Ash Borer Management to County and Municipal staff and to provide information for residents.

The Transportation and Engineering department is responsible for the maintenance of County Roads.  A preliminary survey of roadside hazardous ash trees has been completed and removals of hazardous trees are being completed as required.

A Strategic Plan to Manage the Emerald Ash Borer in Simcoe County

Map of Emerald Ash Borer in Simcoe County