Help, mosquitoes love me!

Zzz… Zzz… Zzz… It’s buzzing around you – and around you alone. You always have that feeling of being a mosquito’s favorite snack when you’re outside. Is this a myth? Is it true that some people attract more mosquitoes than others?

A little over 50 species of mosquitoes share the summer with us in Quebec. And even if about 30% of these mosquito varieties want to bite us, they sometimes ruin our aperitifs on the terrace, our activities in the park or our outdoor outings.

Some people seem to be constantly caught in a cloud of “mosquitoes,” no matter how they move and travel. But is this really the case?

“It’s not a myth!” says André-Philippe Drapeau Picard, research agent at the Montreal Insectarium. “Some people attract more mosquitoes… And it’s also true to say that some people are more whiny about mosquitoes!”

First attraction factor? CO₂or carbon dioxide, that we release. It’s the perfect trace for mosquitoes looking to bite us. Why do they bite us, anyway? “Females need a blood meal to mature their eggs,” explains Miarisoa Rindra Rakotoarinia, scientific advisor at the Institut national de santé publique du Québec (INSPQ). “They use proteins from human blood.”

So, only females sting. Males feed on nectar only.

Heat and power supply

The amount of CO₂ released by a human being varies according to a set of factors: their genes, their metabolism, their skin microbiota (the bacteria and microorganisms that live on our skin), their body size, their diet, etc.

All of this influences the heat a person gives off – and mosquitoes detect this heat.

But be careful, diet seems to be a minimal factor: the science is not clear on this point, for the moment.

“Certain specific emanations linked to certain foods seem to interest mosquitoes more,” says Denis Boudreau, a doctoral student in life sciences at the Université de Moncton. “Only two studies support the fact that drinking beer or bananas is attractive to mosquitoes. Other foods have been tested, but the results are not significant.”

Patterns and contrasts

After detecting our heat, mosquitoes use visual cues to attack us. Within 15 metres, they are able to “spot their prey,” says Boudreau. Their favourite areas? The back of the neck, wrists, ankles and any other exposed body parts.

Mosquitoes have a soft spot for contrasts, such as clothing with high-contrast patterns.

“This is one of the reasons why it is recommended to wear light-colored clothing if you want to avoid being bitten,” explains Mr. Boudreau.

It’s also useful to avoid giving off even more heat, says Drapeau Picard of the Montreal Insectarium. “Dark colours absorb more of the sun’s rays, we will tend to be warmer and therefore give off more CO₂ ” he says.

Climatic changes

It is difficult to predict whether the summer of 2024 will be particularly favorable for mosquitoes: it depends on several parameters, including the amount of precipitation.

One thing is certain: mosquitoes love heat; their survival depends on it. In this sense, climate change could delight them. “A rise in temperatures creates conditions conducive to greater proliferation, especially if there is more rain,” specifies M^me Rakotoarinia, from the INSPQ.

She adds that some new species are showing up in Canada, including tiger mosquitoes, an invasive species capable of transmitting certain exotic diseases such as dengue fever and the West Nile virus. “For the moment, it’s not an issue in Quebec, but it’s something we’re monitoring,” says the scientist.

Five tips to avoid getting bitten

1. Avoid going out at dawn and dusk. These are mosquitoes’ favorite times to get a little meal. Their favorite places? Near ponds, marshes, swamps and peat bogs: they lay their eggs in stagnant water.
2. Apply mosquito repellent. Insect repellents that contain DEET are known for their effectiveness. Be sure to follow the age-specific concentration recommendations on the product. Never put DEET on babies under 6 months old and put a fine-mesh net around the stroller to protect them.
3. Wear light-colored, loose clothing. Or clothing made of thick fabrics; mosquitoes will be unable to bite through them.
4. Do not use body products with floral or fruity scents (perfume, body soap, clothes detergent). Sweet smells attract mosquitoes since they love pollen and nectar.
5. Use a fan or a burner, such as a citronella coil. It’s not so much the lemony smell that keeps them away, but rather the smoke. Also, mosquitoes are not experts at flying: a slight breeze discourages them.