Mosquitoes, standing water and your protection

It makes good sense – from an environmental and a health point of view – to manage standing water on your own property as much as possible, since West Nile virus is linked primarily to one mosquito species – Culex tarsalis – that lays its eggs and develops in shallow pools of warm, sunlit standing water.

Around the yard

• Mosquitoes tend not to develop on large lakes, ponds or sloughs that are affected by wind and waves. In addition, these types of water bodies usually have sufficient aquatic predators to keep any developing mosquitoes in check.
• Be aware of any place where water can collect, in and around your property. This can be a birdbath, unattended pet watering bowl, inflatable wading pool, empty fishpond, old tire, plastic tarp or bucket.
• Do not let water stand in these places for more than a week, especially during the warm periods of summer.
  Note: Chlorinated swimming pools are an exception to the standing water rule. (Mosquitoes and chlorine don’t mix.)
• Rain gutters: clean out rotting leaves and debris to stop water from pooling.
• Rain barrels: use a mesh-screened lid to keep mosquitoes off the water surface. Wrap screening tightly around any open joints on the downspouts.
• Avoid excessive lawn watering. Save water – and keep mosquitoes down!

Acreages and farms

• Drainage ditches and canals: make sure the water in them is kept moving.
• Dugouts: these are designed to hold water, are deep and have steep sides and so they don’t generally support mosquito larvae.
• Check for mosquito larvae in any standing water that has leaked from irrigation canals, reservoirs, waste disposal ponds or septic fields. This water is notorious for the development of mosquito larvae and should be drained if possible.

Around the home

• Check all window screens; repair any holes.
• Keep outside doors closed. Consider installing an automatic door closer, if your family keeps forgetting to shut the door.
• Keep your body covered when mosquitoes are at their most active.
• Use mosquito netting or screened enclosures, to let your family enjoy protected outdoor living in periods of high mosquito activity.
• Your best line of defence is to avoid contact as much as possible. Especially at dusk and dawn, try to avoid vegetated areas (where mosquitoes tend to cluster) and river valleys (where they like to travel).

Domestic pets

• Most domestic animals, other than geese, horses, mules or donkeys, are not at risk for serious illness due to West Nile Virus. Steps can be taken to protect pets from the annoyance of mosquito bites.
• When putting caged pets (budgies, canaries, parrots, reptiles, frogs, snakes or iguanas) outdoors, consider netting or screened protection.
• Examine your dog or cat to make sure they are not being bitten around their eyes or nose. Consider keeping shorthaired pets indoors when mosquitoes are most active.
  

Mosquito Control Products

Acreage and farm areas may have wet areas that cannot be drained, such as roadside ditches. If mosquito sampling of these areas results in more than five larvae per dip (using a water ladle), consider using a mosquito insecticide to kill the larvae.

A new granular insecticide for mosquito larvae control is available at some hardware stores. It contains an active biological ingredient called Bti. Follow directions on the label carefully. Apply on warm days (when the temperature is over 20 degrees). Apply this product only around the margins of larger bodies of water.

This product is effective only as it settles through the water and the mosquito larvae are actively feeding.

Insecticide spraying of adult mosquitoes is not considered to be the best form of control. Mosquitoes can easily hide and avoid contact with an insecticide being applied as a fog or spray.

Repeat applications of insecticide are necessary, as mosquitoes move in from untreated adjacent areas.

Some people are sensitive to the odours and chemicals associated with adult mosquito insecticides. Some products can cause paint spotting on vehicle finishes.

All insecticides that control adult mosquitoes kill many other “good” insects.

Visit Alberta Health and Wellness for more information about mosquitoes and West Nile Virus.