Harmful organisms

Harmful organisms and pests can cause damage to the environment and agriculture and involve risks that may affect public health and the proper conduct of human activities.

It is important, if you see any pests, to report noxious weeds or mosquitoes to the Environmental Health Department, together with the specific location where sighted (address, area on the property) and the approximate density of the pest. If possible, provide a photograph for identification purposes.

Harmful organisms

Giant hogweed

Giant Hogweed (Heracleum mantegazzianum) or Giant Cow Parsley can reach a height of 2 to 5 metres. It is considered a noxious weed and its sap causes phytophotodermatitis, resulting in blisters, burns and scars. It can also cause blindness.

Identification :

Stems and petioles have reddish-purple flecks, nearly solid purple at the base

Leaves are large and shiny with coarse, serrated edges

Flower stalks and leaf stems have stiff, bristly hairs

Giant Hogweed is often misidentified because of its similarity to Cow Parsnip. To learn more on how to identify Giant Hogweed and differentiate it from similar species, visit:

Ministère du Développement durable, de l’Environnement et de la Lutte contre les changements climatiques – Québec (French only)

Space for Life (Montreal Botanical Garden)


Mosquitoes thrive in stagnant water. Some good habits to adopt in order to prevent mosquito breeding are:

At the approach of summer, open your pool as soon as possible

Clean your gutters every spring

Empty outdoor items where water collects (flower pots, boilers, furniture, etc.)

Install screens on rainwater barrels.

Have you noticed a high presence of mosquitoes? Do you have questions about controlling biting insects? Call the Info-mosquito line at 1 (888) 567-8567.

For more information, view the following GDG Environment videos (French only):

Sand wasps

If you see insects swirling over sandy surfaces in Town parks or at the beach, take care. These are sand wasps. They measure two centimetres (3/4”), are coloured black and yellow or black and white and lay eggs in the sand. They are most active when temperatures are high.

As a preventive measure, you are advised to avoid sandy areas if you suffer from an allergy to wasps or are disturbed or frightened by their presence.

West Nile virus

Since 2006, active surveillance for West Nile virus in dead birds has been terminated. Therefore, to provide preventive surveillance for avian influenza in Quebec, residents are urged to report any mortality of wild birds to Services Québec by contacting 1-877-644-4545.

For more information visit:

Public Health Agency of Canada

Contact the Urban Planning Department

For all questions relating to Urban Planning, please contact 450-458-5347.