Emerald Ash Borer


What is emerald ash borer? 

The emerald ash borer (EAB) is a tiny metallic-green insect native to Southeast Asia. It was first detected in in North America in 2002 and has now spread to our area. The EAB attacks only ash trees by getting under the bark of the tree and disrupting its ability to transport water and nutrients and causing trees to die within 3 to 5 years of the attack. Although, the tree may seem to appear healthy, it may be seriously damaged under its bark. When the signs of EAB infestation become apparent to the naked eye, it’s usually too late to save the tree. Unfortunately, millions ash of trees have died since it was discovered in 2002.


                                                                  Credit: Government of Canada

How to identify an ash tree on your property

Ash trees have the following identifying features:  

Ridged bark Mature ash trees have a tight and ridged bark that often displays a diamond pattern of sharp edges. Younger ash trees have a smooth and reddish bark.

Opposite branches Rather than being staggered, branches grow directly from one another (almost forming a V pattern).    

Compound opposite leaves A branch will also have opposite leaves with a leaf at the top. It will also have an odd number of leaves, ranging from 5 to 11.                                         

Seeds When seeds are present, they hang in clusters and are dry and oar-shaped.


How to check if your ash tree is infected

Although it may difficult to visually determine that your tree is infected, the following are signs should not be ignored and you must get a confirmation from a professional arborist certified with the  Société internationale d’arboriculture—Québec (SIAQ).    

Thinning crown, usually starting at the top of the tree

Diminished leaf density, usually starting at the tips of branches

Long shoots growing from the trunk or branches  

Vertical cracks in the trunk                        

S-shaped tunnels under the bark, caused by larvae feeding D-shaped exit holes, caused by emerging adults beetles

                                                                                                                                                                   Credit: Government of Canada 

 Figure 1: Declining crown resulting from EAB infestation - Ches Caister, CFIA staff

 Figure 2: 'S'-shaped galleries between the bark and the wood caused by larvae feeding - CFIA

 Figure 3: Size comparison of EAB larva to a penny - Jerry Dowding, CFIA staff

 Figure 4: 'S'-shaped galleries between the bark and the wood caused by larvae feeding and sprouts or epicormic shoots - CFIA

 Figure 5: 'S'-shaped galleries between the bark and the wood caused by larvae feeding and 'D'-shaped exit holes - Troy Kimoto, CFIAstaff


How to treat your tree

Consult with a professional arborist. If your ash is not infected, or is slightly infected, a low impact pesticide approved by the Canadian Food Inspection agency could be applied as a preventive treatment.  This preventive treatment should be administered between June 1 and August 31,2016 and is to be repeated every two years. In 2016, Côte Saint-Luc will offer its residents a subsidy equivalent to 50% of the cost for treatment, up to a maximum of $400 per property (proof of paiement is required). 


How to fell (or cut down) your tree

If a professional arborist has determined that your tree is too infected for treatment, you will unfortunately have to fell it. Please note that only a certified professional from the Société internationale d’arboriculture—Québec (SIAQ) will be authorized to fell the tree. The felling period for trees infected with EAB will be from October 1 to March 31. Unless your tree is deemed dangerous it can be felled at any time. If the tree is felled during the spring and summer months the wood from that tree will have to brought to the Public Works yard for storage. To fell your tree you will need to complete a permit application form and provide the following information:

Contact information of the arborist felling your tree

Diameter of tree measured at the height of an adult’s chest      

Height of the ash

Crown width of the ash

Cost of the felling    

The permit application form is available at the Urban Planning office (5801 Cavendish) or by clicking here. You can bring the form to the Urban Planning office or email it to urbanplanning@cotesaintluc.org. For the felling of infected ash trees, the city will waive the usual $75 permit fee.


How to dispose of wood from a felled ash tree

Côte Saint-Luc has a drop off site for ash wood that can’t be chipped (such as the trunk and large branches­). This site will accept wood from trees that were felled outside the usual authorized feeling period of October 1 to March 31. This wood can be dropped at the Public Works Yard (7001 Macke), Monday to Thursday from 8 am to 11:30 am and from 12 pm to 2:30 pm and Friday from 8 am to 11:30 am. There is no cost to drop off this wood.


How to get more information

The Société internationale d’arboriculture—Québec (SIAQ) provides on their website, www.siaq.org, a list of professional arborists or contractors that can provide assistance to treat, prune or fell your tree. You can also reach the SIAQ at 450-689-9393. Or contact our Public Works Department at 514-485-6868. 

                                                                                                                                                                                                                                                                          >>View the EAB pdf


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