Emerald Ash Borer 

What is it?

The Emerald Ash Borer (EAB) is an invasive beetle that feeds on and destroys ash trees.

Where is it?

Ash trees are large deciduous (leafy) trees native to our region and found all throughout Brantford.  You will see them on our streets, parks, private properties and woodlots.  It is highly probable all ash trees will get the Emerald Ash Borer and die from the damage they do to the tree.

What does it mean? What impact will it have?

Emerald ash borer and its effects can be seen in every area of the city. The City of Brantford’s arborists survey and manage city-owned ash trees along streets and in parks.  Our EAB strategy is a triage-based approach of tree removals based on worst-to-best condition.  Tree decline is subject to many factors and is therefore hard to predict.  Trees that show steep decline may pose a risk to people, property and activity and should be reported to the City of Brantford.  

Residents are encouraged to contact a certified arborist from a reputable tree care company if they have an ash on private property whether healthy or not (see below to identify if you have an ash tree).   

What is the City Doing?

The City of Brantford’s Forestry department is managing the ash tree population on streets and parks throughout the city.  The triage program of removals of worst-to-best conditioned trees has been implemented based on data collected from the 2012 inventory of public ash trees.  The city’s Forestry department will manage and minimize the risk these dead or declining trees may pose. Note that  all ash trees on city-owned streets, roadways and parks will be removed in time.   

In May and June of 2012, the city surveyed ash trees along Brantford streets and in parks.  (Trees in woodlots and natural areas will not be removed unless they pose a risk to trails, private property or buildings.)  The City immediately started a program of removing declining ash trees.  The City continues to remove the declining trees and will replant suitable species as space allows.  Where space is limited replacement trees will not be planted until after the stump is removed.

Trees to be removed will be marked with orange paint and a notice will be delivered. Free firewood will continue to be available onsite after the removals.  Consider the wood to have the emerald ash borer and use it locally to prevent the EAB’s spread to natural areas of Ontario. 

More Information about Emerald Ash Borer:

Continue reading about the Emerald Ash Borer (below) to get a better understanding of the insect and what it does to ash trees and how it is changing our urban forest. 

Parks and Recreation Urban Forestry
519-759-4150 or submit a Service request by clicking here: Service and Information Request

What is the Emerald Ash Borer?
The Emerald Ash Borer is a beetle that burrows into, nests and feeds on the inner bark of ash trees.
As an adult the insect is 8-14mm in length with a striking
metallic green backside and an emerald green underside. 
They emerge from inverted d-shaped exit holes in May-June
to eat, mate and lay eggs.  They live as an adult for 3-4 weeks.

It is during the larval stage  that the beetle does the damage to the tree.  The eggs hatch and the larvae burrow under the bark.  The larvae will grow to 25-30mm long as it feeds on the inner bark for the majority of the insect’s life.  This feeding destroys the transport system the tree needs to move water and nutrients from the roots to the leaves in the canopy.  Trees can no longer function and tree death follows.  

Do you have an Ash tree?
The Emerald Ash Borer feeds and  lives exclusively in ash trees.  There are several species of ash trees of in the City of Brantford.  White, Green (often European), and less commonly Black Ash can be seen on the streets, parks, backyards and wooded areas of Brantford.  The tree was planted in urban settings for its hardiness and fast rate of growth—it was a great choice for the urban environment and backyards.  However, for those reasons they were often overplanted in some areas.  They’re all very similar in appearance.    

Leaf:  compound with anywhere from 5-13 leaflets
Branching: oppositely arranged  (only ashes, maples & horsechestnut arranged this way)      
Bark: is light to dark greyish, tightly furrowed (‘diamond shaped’), sometimes smooth.

Where did the EAB come from?
Native to Eastern Russia, Northern China, the Korean Peninsula and Japan, the Emerald Ash Borer is an invasive insect likely introduced to the American state of Michigan in the early 1990’s.  It is believed the insect arrived in imported wooden packing materials or crates.  It was officially identified in the Detroit, Michigan, area in 2002.  That year officials in Canada identified the beetle in Windsor, Ontario. 

Signs your ash tree has the EAB
In it’s larval stage the beetle consumes and disrupts the water and nutrient transport system of the ash tree.  The first indication of invasion is general tree health problems.  For trees this means leaves are slightly smaller and colouring is less deeply green.  The tree blooms and leafs out later in the Spring and drops leaves sooner in the Fall.  As tree decline and stress increase twigs and branches will die from the centre-top of the tree downward.  Bark will dry and split on branches and trunk.  To compensate for the loss of leaves the tree will send out ‘sprouts’  throughout the inner branches and along the trunk.

It is rare to see the insect in the striking green adult form as they are in this stage to mate for only 3-4 weeks.  However, you may be able to detect their exit holes in the bark at eye level.  These are small but unmistakeble inverted D-shaped holes in the bark.  Also, as bark sheds you will likely see the ‘galleries’ of larva feeding under the bark or the s-shaped feeding paths the larvae create.  Finally, the presence of woodpeckers is another tell-tale sign that EAB has infected your ash tree.  

How does the EAB spread?
The fastest way for the emerald ash borer to spread is through people moving infected materials such as firewood, logs, branches, nursery stock or other ash wood.  The beetle can fly to a range of up to10 kilometers but prefer to remain in the area surrounding the tree they’ve nested in.  The speed of the EAB’s spread to date can mostly be attributed to our transporting them.   
IMPORTANT:  Comply with federal regulation and do not remove or transport ash wood far from where it was gathered.  In Brantford, please do not transport and expose wood to woodlot and naturalized areas.

What to do about EAB
As noted above the City of Brantford is managing the ash population with a complete monitor and removal program. Feeding exclusively on ash trees, the invasive insect has no natural enemies in North America and the local ash trees have no natural resistance or defence.  Trees will die quickly after infection.
Again, if you have an ash tree on private property it is recommended that you consult an arborist.

For more information on the Emerald Ash Borer and assorted links, visit the EAB page provided by the Canadian Food Inspection Agency. 

Also visit:   




Photo Album

  • The underside of an Emerald Ash Borer which is bullet shaped with a distinct metallic green colour. Emerald Ash Borer is green and has a bullet shape body
  • The "Drunken Galleries" are the tell-tale sign that Emerald Ash Borer is present
  • Using a penny as a scale reference to illustrate the size of the larvae of an Emerald Ash Borer, to the left is an example of the A penny is used as a scale reference to illustrate the size of the larvae
  • The crown thinning that is one of the signs of Emerald Ash Borer or another serious problem with the tree Crown thinning is a sign of Emerald Ash Borer or another serious problem
  • A close-up the "Drunken Galleries"
  • The an adult Emerald Ash Borer on top of a mossy bark, with it's wings fully extended Emerald Ash Borer
  • A thumb with an Emerald Ash Borer on the knuckle to show size of an adult An adult Emerald Ash Borer
  • Wooded area showing the devastation to our forests caused by the Emerald Ash Borer Local forests are affected by Emerald Ash Borer
  • A branch sample taken from a Brantford tree showing the A branch sample showing the "drunken galleries"
  • The metallic coloured Emerald Ash Borer is perched on a piece of bark, which illustrates the distinct colour and eye-shapeEmerald Ash Borer
  • Extensive girdling caused by the A tree that has been devastated by Emerald Ash Borer
  • The Suckering (the small branches coming off the trunk) are a sign of damage to the tree
  • Large cracks in bark, Large cracks in bark, "drunken galleries", as well as the D-Shaped exit hole are signs of Emerald Ash Borer
  • Emerald Ash Borer larvae, which has a pale coloured head and bodyLarvae of Emerald Ash Borer have a pale coloured head and body
  • The penny is used as a scale reference for the Emerald Ash Borer exit holeThe exit hole of an Emerald Ash Borer
  • An ash tree showing epicormic branching, another classic sign of Emerald Ash BorerAn ash tree showing epicormic branching, another classic sign of Emerald Ash Borer
  • An ash tree showing vertical crackingAn ash tree showing vertical cracking
  • A wooded pathway showing trees affected by Emerald Ash BorerWood pathway affected by Emerald Ash Borer