The beginning of June marks the unofficial start of the mosquito season in Canada, with large groups of tiny vampires preparing to invade picnics, barbecues, and other outdoor activities. Heavy rainfall
, coupled with rising temperatures, will cause mosquito populations to explode in the following weeks, entomologists expecting to see multiple distinct peaks between June and September.
Although, in Canada, we often joke that the mosquito is our national bird, mosquitoes are not a laughing matter in most parts of the world. Despite their size and fragility, they cause more human deaths – about 725,000 every year
- than some of the biggest predators on the planet, such as sharks, wolves, lions, elephants, and crocodiles, combined. By comparison, sharks only kill ten people a year, crocodiles 1,000, and snakes 50,000.
The reason mosquitoes cause most human suffering on the planet is because they are effective carriers of pathogens that may cause devastating diseases such as malaria, dengue, yellow fever, various forms of encephalitis, and the notorious West Nile virus.
Among pest-borne diseases, malaria
is by far the worst. Threatening almost half (3.2 billion) of the world’s population, the disease accounts for nearly 600,000 deaths and almost 200 million clinical episodes per year. In high-burden countries, malaria causes billions of dollars in lost productivity annually, trapping “families and communities in a downward spiral of poverty and disproportionately affecting poor people who […] have limited access to health care.”
Fortunately, there is no malaria transmission in Canada today, concerns regarding the disease being limited to tourists, particularly overseas travelers. The mosquito-borne illnesses
that have recently become a growing problem in the Americas, indirectly affecting Canadians traveling to tourist hotspots such as Cuba and St. Martin, include dengue infections and Chikungunya fever, both spread by Aedes
The West Nile virus is, however, the disease that presents the greatest domestic danger. Transmitted by the Culex
mosquitoes that feed on the blood of infested birds and subsequently bite humans, the disease was first reported
in Ontario, Canada, in 2002, when it caused a great deal of concern by killing 14 people. Since then, cases have been reported in several Canadian provinces, including British Columbia, Quebec, Alberta, Manitoba, and others.
What Causes Mosquitoes to Bite Humans?
People who are under the impression that they get bitten more than others are not imagining it. Studies
have shown that an estimated 20 percent of people are high attractor types for the little buggers
, while others rarely get bitten. Most important factors that reel mosquitoes in include:
- Blood type. Some blood types are more appetizing than others: people with Type O are bitten almost twice as much as people with Type A. In addition, certain genes in the body cause 85 percent of people to secrete a chemical signal through their skin indicating the type of blood they have, while 15 percent do not, and mosquitoes are more attracted to secretors than non-secretors, regardless of their blood type.
- Carbon dioxide. Mosquitoes are equipped with an organ called the maxillary palp that enables them to smell the carbon dioxide emitted in their targets' breath, from as far as 164 feet away. Consequently, people who exhale more carbon dioxide, such as tall adults and pregnant women, get bitten more, while those who produce smaller quantities of the gas, such as children, are usually not as threatened.
- Perspiration and body temperature. Carbon dioxide is not the only chemical magnet for mosquitoes. Lactic acid, uric acid, ammonia, and other substances produced via perspiration can make some humans stand out as targets to the insects.
- Movement. The insects are able to locate their victims by perceiving the changes in waves of light around them, caused by moving objects. Therefore, active people or those who are exercising will get bitten more often than static people, as they exhale more carbon dioxide, have higher humidity around their bodies, and release more lactic acid.
- Clothing color. Mosquitoes also use their sense of vision to locate potential targets, therefore people wearing colors that stand out, such as red, blue, and black, are more prone to their attacks.
- Strong fragrances. Strong perfumes, colognes, shampoos, soaps, hand creams, fabric softeners and detergents will make you more attractive to mosquitoes.
Canadian homeowners who want to avoid mosquito bites this summer should start by eliminating all bodies of standing water and humid soil in order to cut down on the available habitat. Pools and ponds, as well as flower pots and gutters, have the potential to turn into breeding sites for the tiny critters. Contact your local pest control company
to help identify and eliminate potential problem areas on your property, and also discuss safe, non-toxic methods of removing existing populations from your home and garden.
About the Author
Daniel Mackie, co-owner of Greenleaf Pest Control, is a Toronto pest control expert well-known as an industry go-to guy, an innovator of safe, effective pest control solutions, and is a regular guest on HGTV. Mackie, along with business partner Sandy Costa, were the first pest control professionals in Canada to use detection dogs and thermal remediation for the successful eradication of bed bugs. In his free time, he is an avid garde