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Health and Environment

Mosquitoes, Ticks and Insect Pests


Mosquitoes are insects that live on nectar and sap. The female bites to feed on blood, an essential nutrient for laying eggs.


    • Eliminate stagnant water. Regularly clean gutters so they will not block and retain water. Empty flowerpot saucers, animal bowls, wading pools, pool covers and other similar items (pails, barrels, tires). Empty and clean the birdbath twice a week.
    • Keep your environment clean. Cover your garbage cans. Maintain your pool. Install screens on your rainwater barrels. Add fish that eat mosquito larva to your decorative pond.
  • It is important to protect yourself from mosquito bites because mosquitoes can carry West Nile virus and other diseases. Follow these instructions:

    • Wear long, light-coloured clothing when you are outside.
    • Repair holes in window and door screens and tent and camping shelters.
    • Use mosquito repellent during outdoor activities.
  • Since 2017, Ville de Châteauguay has stopped all insect control operations across the territory, in keeping with new restrictions imposed by the Ministère des Forêts, de la Faune et des Parcs (MFFP). The MFFP has found threatened species in many locations, including Île Saint-Bernard, the Refuge Marguerite-D’Youville and other small marshes nearby, and although the product we were using, common in organic farming, is safe for humans and animals, the bacteria it contains could be detrimental to certain species.


Ticks are not insects but a kind of parasitic mite that feeds on human and animal blood. A small proportion of the ticks in Châteauguay may carry the Borrelia burgdorferi bacteria, which causes Lyme disease.


    • There are 12 species of ticks in Québec.
    • They live in:
    • Wooded areas, forests, undergrowth, shrubs and brush
    • Tall grass, unmaintained land
    • Gardens near wooded areas, shrubs, brush or tall grass
    • They range in size from 1 mm to 3 mm before a meal and 3 mm to 9 mm when they have gorged on blood.
    • The species of tick that carries the bacteria that causes Lyme disease is Ixodes scapularis. They are also known as “deer ticks” or “black-legged ticks.” Lyme disease is transmitted by the bite of an infected tick.
    • Lyme disease is often transmitted by ticks in the nymph stage, which stay attached to their hosts for longer before being detected due to their small size. Nymphs are also active all summer long.
    • Lyme disease must be taken seriously, because it can lead to severe consequences such as arthritis and attacks on the nervous system if not treated in time.
    • Cut the tall grass and brush around your home and mow the lawn, especially around children’s play areas.
    • Remove dead leaves, brush and weeds from your lawn and from around wood piles and the shed.
    • Lay borders with wood chips or gravel between wooded areas and lawns, patios and children’s play areas.
    • Set up play areas away from trees, in sunny areas.
    • Stack wood carefully, in a dry, sheltered place, to avoid attracting rodents, which, in turn, attract ticks.
    • Do not leave old furniture and items in your yard.
  • When you are doing something outside in the forest or woods:

    • Walk on paths if possible and avoid tall grass.
    • Use an insect deterrent that contains DEET, picaridin or icaridin (products that deter insects) on the exposed parts of your body, avoiding your face.
    • Wear a hat, closed shoes and long, light-coloured clothing.
    • Tuck your shirt into your pants.
    • Tuck your pants into your socks or boots.
    • After outdoor activity, examine your clothing and equipment (backpack, etc.). This will allow you to avoid bringing a tick inside.
    • Also examine your pets, because they may bring in ticks. If you find ticks on an animal, remove them and contact a veterinarian if necessary.
    • Examine your entire body after activity in a wooded area. Ask for help from another person or use a mirror to check areas that are harder to see, such as your back. Also examine children. If you find a tick, remove it by following the instructions on the Removing a tick after a bite page of the Québec government health portal.
  • The Direction de la santé publique de la Montérégie has created a webpage to provide information to the public about:

    • Areas at risk of tick exposure in the Montérégie, with an interactive map
    • Ways to protect yourself from ticks
    • What to do if you are bitten by a tick
    • The main symptoms of Lyme disease

    Photos and videos are also available.

    • The Direction de la santé publique has raised the awareness of municipal employees.
    • Signs have been put up and information brochures are available in municipal buildings.
    • The Service des travaux publics maintains parks to reduce the presence of ticks.

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