Mosquitoes

Learn about mosquitoes, how to control them, and how to protect yourself from their bites.


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What are mosquitoes?

Mosquitoes are small insects that bite. Because their bites can also cause itchiness and irritation, many people try to avoid them.

Mosquitoes grow in still or very slow-moving water. Some mosquitoes lay their eggs on the surface of the water. They lay between 100 and 400 eggs at one time.

The eggs hatch in 1 or 2 days into larvae, which look like small worms. The life cycle from egg to adult can take less than 10 days if the temperature is right. The ideal temperature is between 22° and 27°C.

Only female mosquitoes feed on animal or human blood. They need blood in order to produce eggs.

How can you control mosquitoes?

Natural predators provide some control of mosquito populations because they eat their larvae. Predators include:

  • fish
  • frogs
  • beetles
  • dragonflies
  • water bugs
  • birds that live on or around water

You can help control mosquito populations by preventing them from breeding or preventing the larvae from developing into adults. You do this by:

  • removing standing water which provides breeding sites
  • controlling the larvae with an approved product

Since mosquitoes lay their eggs in still or standing water, even very small quantities of water can be a problem. This includes puddles.

Remove sources of standing water on your property by:

  • keeping your gutters clean
  • emptying tire swings of water
    • to avoid the problem completely, replace the tire with another type of swing
  • storing flower pots, watering cans, boats and wheelbarrows upside down
  • replacing water in bird baths and outdoor pet dishes at least twice a week
  • covering garbage, recycling or composting containers to prevent water from gathering
  • drilling holes in the bottom of containers that must be left outdoors uncovered
  • emptying your rain barrel if the water is over a week old, unless it's protected with a fine screen

You can also remove breeding sites by:

  • repairing leaks from outdoor water pipes, joints or hoses
    • replace washers on outdoor taps that drip
  • getting rid of water that collects in low spots on your property
  • keeping your swimming pool cleaned and chlorinated even when not being used
    • dump any water that collects on your swimming pool cover
  • aerating your ornamental pond, which creates oxygen bubbles in the water
  • checking under shrubbery and lawn coverings for hidden containers or pooling water
  • turning over plastic wading pools when not in use and changing the water at least twice a week

Controlling the larvae with an approved product

Sometimes it's not possible to remove all potential mosquito breeding sites. In this case, you can use a mosquito larvicide. Only use an approved mosquito larvicide, which will have a pest control product (PCP) number on the label.

To find the right product, consult the Pesticide Label Database of registered products. Be sure to read the label carefully and follow all directions.

Mosquito larvicides include products that have:

Use these products in water that cannot be emptied, drained, flushed or changed on a regular basis, like:

  • ponds
  • rain barrels
  • flower planters
  • ornamental ponds
  • low-lying spots that flood

Products that don't control mosquito populations

Devices designed to repel or trap and kill mosquitoes aren't effective at reducing mosquito populations. These items include:

  • lanterns, coils and sprays
  • bug zappers (called electrocutor traps)
  • electronic mosquito repellers that emit a high-frequency sound

Health risks

Around the world, mosquito bites can lead to a range of diseases, including malaria and the Zika virus.

In Canada, West Nile virus is a health concern. However, for most Canadians, the risk of getting this illness or serious health effects is very low.

How can you protect yourself from mosquito bites?

In most parts of Canada, mosquitoes are common from May to September. Mosquitoes can bite at any time of the day, but they tend to be more active between dusk and dawn. If you can, limit your outdoor activities as much as possible during this time.

You can also take the following steps to protect yourself:

  • Use a fly swatter to kill mosquitoes in the home.
  • Use an approved insect repellent with a PCP registration number on the label.
    • Read and follow all label directions.
  • Wear loose clothes made of tightly woven materials that keep mosquitoes away from your skin, such as nylon or polyester.
  • Use mosquito netting when sleeping outdoors or in an unscreened structure. Also use netting to protect infants when outdoors.
  • Wear long pants and sleeves as well as shoes and socks. You should do this if you're going to be outside when mosquitoes are most active.
  • Fix or replace old and torn screens in doors, windows and vents. Inspect all other possible access points into your home and fix as needed.
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