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Emerald ash borer

Agrile du frêne

The emerald ash borer (Agrilus planipennis) is an invasive insect native to Asia that threatens all species of ash trees. Infested trees generally die after two or three years, but severely attacked trees may die in only one year. This beetle is responsible for the death of millions of ash trees in Ontario and the northeastern United States.

Last May, the Canadian Food Inspection Agency (CFIA) confirmed the presence of the emerald ash borer in the Longueuil agglomeration. Here is some information on how to recognize this insect, limit its spread, and identify and treat an infested tree.

Introduction to the situation

Produced in June 2016, this video (in French only) presents the problem of emerald ash borer in Greater Montreal and the ways to fight against it. It is a production of the Montreal Metropolitan Community (CMM), with funding from the Caucus des municipalités de la métropole de l'UMQ.

How to recognize the emerald ash borer?

Larve et adulte agriles du frêneAdult

Emerald ash borer adults are slender, metallic green, winged insects measuring 8.5 to 14 mm long (about ½ in.) and 3.1 to 3.4 mm wide (about 1/8 in.). Their heads are flattened and their eyes are generally black. They can be observed on a tree from mid-May to the end of July.


Mature emerald ash borer larvae are white and measure between 26 and 32 mm long (about 1 in.). Larvae have bell-shaped abdominal segments.

How to recognize an ash tree?

FrêneAn ash tree is a deciduous tree in the family Oleaceae, measuring from 25 to 40 m high. It can live up to 200 years.


The leaves are green in the summer and yellow in the fall, and are made up of 4-10 leaflets positioned opposite one another on a stalk with one single leaflet at the top.


The ash tree produces long, narrow, green fruit, known as samaras, that hang in clusters until the end of winter.


The bark of a mature ash tree is grey and has a ridged or furrowed appearance. On younger trees, the bark is light grey and smooth.

How to recognize an infested tree?

Signes d'un frêne infesté par l'agrile du frêneHere are a few signs that might indicate a tree is infested. Note that the first signs will be exhibited at the crown:

  • Abnormal crown thinning, premature yellowing of foliage, progressive crown dieback, and dead branches at the top of the tree (1);
  • Unusual and heavy samara fruit production;
  • Growth of shoots in unusual places on the lower portion of the trunk (2);
  • Vertical cracks in the bark (3)and S-shaped galleries under the bark (4) caused by feeding larvae;
  • D-shaped holes in the bark where the beetle exits the tree (5);
  • Irregular notches in ash leaves caused by adult insects feeding (6);
  • Increased presence of woodpeckers, who feed on the larvae, and feeding holes.

What should I do if I think my tree is infested?

It can be difficult to identify the signs of an emerald ash borer infestation. Some symptoms may be caused by other diseases.

If you suspect your tree has an emerald ash borer infestation, we recommend you consult a qualified expert (arboriculturist, horticulture specialist, forestry engineer, tree pruner, etc.). You can obtain a list of experts from the website of the Société Internationale d’Arboriculture Québec inc. (SIAQ) at

Once the diagnosis has been confirmed, the expert will be able to go over the different options available to you.


In the case of a minor infestation, your tree can be treated with an insecticide called TreeAzin®. This product can effectively control an emerald ash borer infestation, though it cannot guarantee the tree’s survival and must be repeated every two years.

If you decide to treat your tree with TreeAzin®, it is important to note that only qualified people can inject it. To find a professional or to know more about TreeAzin®, consult the BioForêt website at

Before hiring a professional, we recommend that you make sure they have a permit to use TreeAzin®, by calling the City of Saint-Lambert’s Town Planning, Permits and Inspection Department at 450 466-3277.

Cutting down a tree

If 30% of an ash tree is suffering from dieback, the infestation is generally considered to be too far advanced to treat and save the tree. In this case, the tree must be cut down between October 1 and March 15 to prevent the emerald ash borer from spreading. Outside this period, it is strongly recommended to avoid cutting down a tree unless it poses a potential danger, due to the high risk of spreading the infestation.

To cut down a tree, you must generally obtain a permit from the Town Planning, Permits and Inspection Department. They can be reached at 450 466-3277.

Because the CFIA has issued a ban on the transportation of all ash tree materials outside the regulated area, the contractor whom you hire to cut down your tree must comply with this regulation.

zone de l'agrile du frêne

How can we limit the spread of the emerald ash borer?

Following confirmation of the presence of the emerald ash borer on the territory of the Longueuil agglomeration, the Canadian Food Inspection Agency (CFIA) expanded its regulated areas for the emerald ash borer to include the agglomeration.

Subsequently, the CFIA issued a ban on the movement of all ash materials, including branches, logs, stumps, chips, or firewood, out of the regulated area (yellow area on map).

How can I dispose of my branches and leaves?

Branches are now accepted in the green waste collection, under certain conditions:

  • Branches must be less than 5 cm in diameter.
  • Branches may not be longer that 1 m.
  • Branches must be tied in bundles of not more than 40 cm in diameter.

Anytime, you can dispose of your branches and your wood (logs, stumps, chips, firewood, etc.) by taking it to the Écocentre Marie-Victorin or to the Écocentre Grande Allée.

How can I find more information?

Following confirmation by the Canadian Food Inspection Agency (CFIA) of the presence of the emerald ash borer on our territory, the City of Saint-Lambert held an information meeting on the emerald ash borer on June 27. After an explanation of the si tuation, the speakers presented ways of detecting the beetle’s presence and limiting its spread.

This video is courtesy of Jacques Marchand (MédiaSud).

You can consult 

Logo PDF

Présentation de la séance d'information du 27 juin 2013 (in french only)

Status report 

As part of its action plan to combat the spread of the emerald ash borer, over the 2014 summer the City of Saint-Lambert prepared its second status report on the presence of this insect on its territory.

The goal of the report is to obtain as accurate a portrait as possible of the situation of the emerald ash borer on the territory. The report also provides an update of the various projection scenarios and serves as a municipal management tool to optimize the action plan with the ultimate goal of ensuring the sustainability of our urban forest.

This summer, using sticky traps strategically place throughout the territory, debarking, and visual analyses, the City was able to collect the information it needed to analyze the situation.

You can consult the Rapport de situation sur l'agrile du frêne 2014 (in French only).

2013 status report

The conclusion of the 2013 status report was that the emerald ash borer was present throughout the territory. You can consult the Rapport de situation sur l'agrile du frêne 2013 (in french only).


For more information, residents can consult the CFIA website at or the Conseil québécois des espèces exotiques envahissantes website at
Citizens can also contact the City of Saint-Lambert green squad at