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How do mosquitoes choose the skin they bite?

As soon as a mosquito roams the room, you already know that the bite will be for you. Even if you are surrounded by the whole family. But then, is it true that there are « mosquito skins »? Let’s disentangle the true from the false.

At night you hear the incessant buzz of a mosquito and when you wake up, a beautiful bite adorns your cheek. Your partner slept very well. While out for a walk with friends you spend your time feeling small attacks on your legs, your arms, your back. Like vampires thirsty for fresh blood, mosquitoes would therefore have a particular attraction for certain skin types … including yours! In fact, you will see that the reality is a little more complex than that.

Mosquitoes do not smell sugar in the blood, but are sensitive to odors

We often hear that mosquitoes are particularly attracted to sweet blood. An assertion that has absolutely no scientific basis, insects do not have the ability to hate high blood sugar levels. On the other hand, they are sensitive to odors. And we’re not talking about perfume or vanilla shampoo here, but body odors.

So perspiration is particularly attractive to mosquitoes and on this point, we are not all equal. Some will have a very smelly sweat, others not at all.

In 2017, neuroscientist Helen Shen explained in the journal PNAS that « humans send hundreds of scent molecules into the air ». Molecules to which insects are sensitive and which are therefore useful for them to target us.  » These are the smells that attract the mosquito, its sense of smell being very powerful. Indeed, it can detect nearly 150 different issues from the human body », explained Gregory L’Ambert, head of the Methods and Research unit at the Entente. interdepartmental for mosquito control of the Mediterranean coast, in Sciences et Avenir in 2014.

Mosquitoes, sensitive to carbon dioxide

But smells aren’t the only things that attract mosquitoes to one skin more than another. Insects are indeed very sensitive to the level of CO2 that we breathe out. They would even be able to detect these CO2 emissions up to 30 meters away. And several elements influence the quantity of carbon dioxide present in the exhaled air: alcohol consumption, overweight, body temperature.

One category of the population is even particularly targeted by mosquitoes for this reason: pregnant women. According to a study published in the British Medical Journal in 2000, pregnant women emit 21% more CO2 than an average person.

The group O blood-hungry tiger mosquito

The tiger mosquito , Aedes Albopictus, which can transmit dengue or chikungunya in particular, would be sensitive to the blood group. A Japanese study carried out in 2004 showed that the tiger mosquito was more attracted to individuals of blood group O. People of this blood group have an 85% increased risk of attracting mosquitoes, compared to only 45% of risk for others. blood groups.