Giving blood is laudable and gratifying – except when the blood is being collected by an insect! Here are some practical tips for staving off mosquitoes, black flies and midges.

A mosquito stings, a fly bites
thrive wherever shallow, stagnant water is found, whether in the countryside, suburbs or cities. Ponds, swamps and ditches are excellent incubators for their larvae, as is water lying dormant in tires, gutters or birdbaths.

Mosquitoes draw their energy from flower nectar. For females, however, blood is an indispensable food supplement for egg formation – which is why they sting.

In regions with plenty of fast-flowing water (creeks, small rivers, etc.), the annual blood drive is held by black flies, while tiny midges, which usually abound in decomposing organic matter, rule in very damp areas.

This fearsome squadron includes other heavyweights: exasperating deer flies, specializing in the wet skins of bathers and canoeists, as well as assorted flies and horseflies that occupy our pastures.

Although they develop and evolve in different habitats, these insects have one thing in common: they bite and cut into the skin rather than stinging. As with mosquitoes, it is only the females, hunting for proteins to bring their eggs to term, that take blood samples.
A warning to anyone in the crosshairs of any of these vampires: what attracts them are a person’s movements or the carbon dioxide (CO2), heat or odour that humans give off.

It itches!
What causes swelling and itching is the anticoagulant contained in an insect’s saliva and injected at the time of a sting or bite. These reactions generally last a few hours or, at worst, a few days.

But check with a doctor if the reaction occurs somewhere other than the place of the sting or bite. In case of violent reaction (swelling of the face, widespread rash, change of voice, difficulty swallowing or breathing, asthma attack, weakness, persistent vomiting, loss of consciousness or state of shock), call an emergency medical service or 911 right away.

Effective measures against tenacious predators
The best way to avoid being a target of these insects is not to breed them on your property and, of course, not to attract them to yourself.

Around the house
Here are a few precautions to maximize protection and make your  yard less welcoming:

  • Make sure no water is stagnating in the gutters.
  • Empty wading pools and flip over wheelbarrows and boats. Remove water accumulating on pool covers, in saucers under flowerpots, etc.
  • Cover garbage cans, recycling bins and other containers, or drill holes in the bottom of containers that cannot be covered. 
  • Replace water in birdbaths and pet bowls at least twice a week.
  • Cut dense vegetation (hedges, tall grass, etc.) where mosquitoes and other insects like to hang out.
  • Check the condition of mosquito screens. In rural areas, choose mosquito screens with a tight weave to keep midges out.
  • Make sure outside doors close hermetically.
  • Repair leaky faucets and gardening hoses.
  • Limit outdoor lighting and, when necessary, install yellow bulbs.

Note that some devices claiming to eliminate insects or to keep them at a distance are very ineffective against mosquitoes. This is true of devices with an ultraviolet light source and electrified grating intended to electrocute insects. According to the Insectarium de Montréal, studies have estimated that only 3% to 5% of the insects they attract are mosquitoes. Moreover, females hunting for blood may be more excited by people than by light. As regards devices that emit ultrasound, tests have shown that female mosquitoes are insensitive to very sharp sounds.

Personal protection
Dress from head to foot, keeping your wrists, ankles and neck covered. If necessary, you can also cover your head with mosquito netting with the type of mesh used by beekeepers. Also, it is advisable to wear loose clothing that breathes, preferably pale in colour, and to avoid scented shampoo, perfume, after-shave lotion, etc.

You can also protect exposed skin by applying an insect repellent bearing a pest control certification number and labelled as an “insect repellent for use on humans.” According to Health Canada, the proportion of DEET (diethyltoluamide) in such products should not exceed 30% for adults or 10% for children aged 2 to 12. It is advisable to select a product with a lower concentration of insect repellent and to apply repeatedly as required. Ideally, insect repellent should be applied to clothing and not directly on the skin.

Use of this type of insect repellent should not be used for infants less than six months old. To protect your baby, place mosquito netting around the cradle, playpen or stroller.

La toile des insectes du Québec (Insectarium de Montréal)