Harmful and beneficial insects

The emerald ash borer is an exotic and invasive insect that feeds on ash trees. Discovered in Michigan in 2002, it has since killed tens of millions of ash trees in North America. This small insect is metallic green in colour and has a narrow and elongated body measuring 7.5 to 15 mm long and about 3 mm wide.

The emerald ash borer easily spreads with the transportation of firewood. In fact, since April 1, 2014, the Vaudreuil-Soulanges area has been considered a regulated area—it is prohibited to move ash products out of a regulated area or property targeted by a prohibition of movement without the prior consent of the Canadian Food Inspection Agency (CFIA). For more details, visit the CFIA’s Web site.

Cutting down ash trees

No matter the reason you wish to cut down a tree, you must first obtain a certificate of authorization from the Environment Department. Note that this certificate is obtained free of charge. Ash trees must be cut down between October and March to limit the spread of the emerald ash borer.

Visit the sites below for more information:

• Don’t move firewood
• Pest alert
• Detecting the presence of the emerald ash borer: Signs and symptoms
  • Emerald ash borer: Find the beetle! (Activity for kids)
• Recommended alternatives to ash trees
• Fact sheet
• Questions and answers
  • Wasps as biological control agents for emerald ash borers

Municipal action plan

To counter the effects of the possible disappearance of ash trees in our area, the City recommends that citizens plant a variety of plant species. The more diversified our forest cover is, the better it will be able to resist new diseases or infestations. The City provides financial assistance of up to $150 per year to residents who plant new trees chosen from a predetermined list of tree species.

The Gypsy Moth Caterpillar, also known as the Bombyx disparate or Lymantria dispar in its butterfly form, is easily recognizable thanks to its back adorned with:

• two rows of five blue dots
• six pairs of red dots, and
  
• long hairs that can cause an allergic reaction when they come into contact with your skin

Reproduction and feeding

Accidentally introduced in North America in 1868–1869, the Gypsy Moth Caterpillar

• Reproduces extremely rapidly as it lays masses of 100 to 1,000 eggs during migration
• Feeds on tree leaves: oak, maple, birch, etc.

Minimize its impact

If its presence on your property bothers you or affects the health of your trees, here are a few tips to help minimize its impact.

• Place a 45-cm burlap canvas around the trunk of the infested tree where the caterpillars take refuge from predators during the day.
• Collect them in a bucket filled with soap and water, or bleach and water, to drown them.

To help prevent population growth the following year:

• Between August and May, remove any masses of eggs you may find on trees, under branches, on outdoor furniture, on the walls of your house, on play structures, etc.
• Drown eggs in a bucket filled with soap and water, or bleach and water, for 2 days

Visit the following sites for more information:

Government of Canada
Space for life

Burrowing wasps are solitary insects that do not build nests, but rather lay their eggs directly in sand or in dry sandy soil. Sandboxes in playgrounds are some of their favourite spots. Unlike other species of wasps, however, burrowing wasps are not very aggressive. Studies done by City of Montréal specialists have shown that while it is not impossible to be stung by a burrowing wasp, it is highly unlikely since these wasps tend to avoid humans who invade their space.

Burrowing wasps are beneficial to our ecosystem. They help pollinate flowers and get rid of certain pests such as flies. It is best to tolerate their presence as long as they are not creating any issues.

Public Works actively monitors areas where sand is present and rakes these areas as needed

White grubs are actually the larvae of June bugs or Japanese beetles. They are usually not a problem unless they are present in large numbers in your grass. They devour grass roots, attack mainly weaker plants and attract skunks and other small animals who love to eat them. Here are a few tell-tale signs of a grub infestations :

• Your lawn looks like it has been ploughed, either in the spring or the fall.
• You see lots of overturned clumps of grass. These are likely caused by skunks looking to eat the white grubs.
• There are other visible signs of damage to your lawn, namely patches of wilted yellow grass.

For more information on these insects, consult the fact sheet in the Publications section.