Emerald ash borer

The Emerald ash borer (Agrilus planipennis) is a metallic blue-green insect 7.5-15 mm in length. It is an invasive exotic species originating from Asia that attacks and ultimately kills all types of ash trees. There are few natural predators to limit the spread of the emerald ash borer in Canada.

What does an ash tree look like?

In North America, the emerald ash borer attacks all species of ash trees.

Below are the most common types of ash trees in Québec:

Latin name English name
Fraxinus americana White ash or American ash
Fraxinus excelsior European ash or common ash
Fraxinus nigra Black ash
Fraxinus pennsylvanica Red ash, green ash
Fraxinus quadrangulata Blue ash

AshAsh trees can grow up to 15-20 meters in height (about 45-60 ft.) and can live for over a hundred years. The leaves of the ash tree are generally green in summer and yellow in fall, and are made up of 5-11 leaflets positioned opposite one another on the stalk. Ash trees produce thick clusters of long, green samara fruit that often stay on the trees during winter.

Ash leav (can have 5 to 11 leaflets)

mature ash trunkAsh trees are found in abundance in both urban and rural landscapes, commonly seen in parks, along streets, and in forested areas.

Source : Ville de Boucherville

Signs of an infestation

It is difficult to identify the signs of an emerald ash borer infestation in an ash tree. For this reason, it is best to consult a qualified expert, such as an arborist, a forestry engineer or a tree pruner. If you don't already know one, you can obtain a list of experts from the Société Internationale d'Arboriculture-Québec inc.

If you think you've found signs of an infestation on your ash trees or that you might have caught an emerald ash borer (adult insect, larva or nymph), contact the Canadian Food Inspection Agency immediately at 1-866-463-6017.

The specific signs of an emerald ash borer infestation are:

  • The presence of S-shaped galleries under the bark of the ash tree, sometimes filled with fine brownish sawdust (never peel the bark off a tree unnecessarily);
  • The presence of small D-shaped holes in the bark of the branches or the trunk;
  • While certain signs are associated with the emerald ash borer, other diseases or insects can cause similar damage:
    • Progressive crown dieback, possibly leading to yellowing of the foliage, crown thinning, heavy and unusual samara fruit production, or dead branches.
    • Sudden growth of vigorous water sprouts on the ash trees in unusual places, especially on the trunk.
    • Vertical cracks in the bark can reveal galleries dug by a larva. At a more advanced stage of infestation, the bark over these galleries easily lifts and sometimes falls off the tree in pieces. Never peel the bark off a tree unnecessarily.
    • Presence of irregular notches in ash leaves caused by adult insects feeding.
    • Presence of woodpeckers or squirrels on the trunk of severely diseased ash trees.
    • Presence of dying or dead trees in a stand of ash trees.

S-shaped galleries: severely infested tree
S-shaped galleries: severely infested tree

Vertical cracks in the bark
Vertical cracks in the bark

Dying or dead trees in a stand of ash trees
Dying or dead trees in a stand of ash trees

Applicable laws and by-laws in Longueuil

Municipal by-law

Pursuant to Ville de Longueuil by-law CO-2009-578 a certificate of authorization is required to cut down any tree (dead or live). Contact the Direction de l'aménagement et de l'urbanisme for detailed information on the applicable standards in your borough, or visit one of the service counters.

If you think you've found an emerald ash borer on a tree on private property:

Ville de Longueuil is responsible for all public trees, i.e., those found along streets, in parks, and on municipal lands and woodlands. However, residents are responsible for the trees located on their private property.

Here's what to do if you suspect that a tree on your property is infested by the emerald ash borer:

  1. Make sure it is really an ash tree (see images above).
  2. Check if the signs correspond to an emerald ash borer infestation.
  3. Contact an arborist or a horticulturalist to confirm the diagnosis and explore possible solutions.
  4. Cut down the tree if it is severely infested and could cause injury or property damage; make sure to get the necessary permit beforehand.
  5. Inform the contractor you hire of the CFIA ban on transporting ash trees outside of regulated areas.
    If the contractor plans to move the felled ash tree outside of the regulated area, he must first chip it into pieces of about 2.5 cm x 2.5 cm (1 in. x 1 in.), in compliance with CFIA requirements. The contractor's chipping equipment must also be CFIA certified.
  6. For a minor infestation, you could consider treating the tree with TreeAzin®. Costs of the treatment are at the property owner's expense.

To reduce the risk of the emerald ash borer spreading, branches and trunks of all sizes and from all species must be brought to the Marie-Victorin and Grande Allée ecocentres. The volume of waste materials per visit cannot exceed 2.5 m³.

Green waste should also no longer be placed in waste containers. You can reuse grass cuttings by practicing grasscycling, a simple, economic, and eco-friendly way to fertilize your lawn. Other garden waste can be placed in home composting bins.

If you think you've found an emerald ash borer on a tree on public property:

  1. Write down the address or exact location of the tree.
  2. Take a few photos, if possible.
  3. Contact Ville de Longueuil at 3-1-1.

What happens to an ash tree infested by the emerald ash borer?

The tree can be treated with an insecticide called TreeAzin®. If the tree is severely damaged, it may be best to cut it down and chip it.

  • Since TreeAzin® is an approved systemic insecticide, it can be used in Longueuil without formal authorization as long as the manufacturer's instructions are followed.

Only qualified persons (arborists and trained tree pruners) can inject TreeAzin®. Consult the Bioforest website for more details about TreeAzin®.

For more information:

* New CFIA measures protect uninfested areas of Canada from the emerald ash borer