Emerald Ash Borer

The Emerald Ash Borer was first spotted in Vaudreuil-Dorion in the summer of 2015. This suggests that the entire city is now at high risk of being affected.

The insect

The Emerald Ash Borer (Agrilus planipennis) is a beetle from Asia, whose presence was confirmed in North America in 2002 (Detroit and Windsor) and then in Carignan, Quebec, in 2008. Since then, many Quebec cities have been struggling with this insect pest that attacks all types of ash trees and spreads with astounding speed.

The Emerald Ash Borer can fly several kilometres. However, transporting firewood is the main factor in its spread. It is therefore essential not to bring firewood to a campsite or cottage and to risk contributing to the invasion of areas that are not within already infested municipalities.

Identification of ash trees

There are three species of ash trees on the territory—White Ash (Fraxinus americana), Red Ash (Fraxinus pennsylvanica) and Black Ash (Fraxinus nigra). Their recognition features are essentially the same:

  • Leaves composed of 5 to 7 leaflets
  • Opposite branches
  • Mature tree: Bark quite thick, formed of stiff crests, crisscrossed in regular diamonds. However, the bark of black ash is rather scaly.
  • Young tree: Bark smooth and thin

Once you have identified your ash trees, enter them in the Géo-Frêne ash tree georeferencing application. This tool, intended primarily for citizens, will contribute to a better understanding of the distribution of ash trees in Quebec and elsewhere.

Signs of infestation

Signs become visible on the ash tree 3 or 4 years after the onset of infestation. The most striking signs are a general decline of the tree, indicated by premature yellowing of foliage, dead branches and thinning-out at the top. D-shaped holes may be visible on the bark and S-shaped tracks can be seen under the bark. Many suckers (new branches) on the tree also indicate the presence of the insect. The tree generally dies in under 7 years.

Treatment

Healthy ash trees or those lightly affected by the ash borer can be preventively treated with a botanical pesticide, TreeAzin®. The City offers a subsidy for the application of this treatment, i.e. 50% of costs, up to $200 per tree (maximum of 2 ash trees per year per residence). To find out about contractors offering TreeAzin® treatment, visit the BioForest website. In times of low infestation, such as in Vaudreuil-Dorion at present, it is recommended that ash trees be treated with TreeAzin® every 2 years. Contractors must have a registration certificate from the City for the application of low-impact pesticides.

Tree felling

If the tree is heavily infested, it is not effective to treat it and it’s therefore recommended to cut it down before it becomes weak and dangerous, and also to limit the risk of infestation. Zoning By-law 1275 permits the felling of ash trees between October 1 and March 15, unless the tree is a safety hazard.

Contact the Environment Division, which will issue the felling permit (free).

Action by the City

In the summer of 2014, the City drew up an inventory of public ash trees. Each summer, traps are installed to detect the presence of the insect. On public lands, work has already begun. Ash trees in poor condition are felled and replaced by other tree species, while some of the healthy trees are treated to protect them from the Emerald Ash Borer. In 2015 and 2016, 200 public ash trees were treated with TreeAzin®.

Only 10% of urban trees in Vaudreuil-Dorion are ash trees.

An action plan for ash trees on public and private land was introduced in 2015 and updated in 2016.

Freinons l'agrile!