Mosquitoes’ preferences finally elucidated…

It’s a fact: some people are systematically bitten more than others, to the point that it becomes a real nuisance during the summer months. But what are the factors behind this phenomenon?

According to common belief, mosquitoes would rather bite people with sweeter blood. While it is not false that these insects are attracted to these odors, they are rather interested in blood for the nutrients it contains. In fact, the mosquitoes that bite are exclusively the females, because they need these nutrients to produce their eggs.

In addition to the blood components, certain molecules covering the skin are a real mosquito bait, fatty acids in particular. However, the researchers that studied this question were unable to identify any molecule that would have repelled mosquitoes in individuals with few bites. But is the attraction of mosquitoes only due to these molecules? To answer this question, the experiment was repeated with mosquitoes lacking the olfactory receptors required to detect fatty acids. These insects were still more attracted to individuals with a large amount of fatty acids on their skin, suggesting that other molecules might be at play. The compounds mentioned in other studies are for example carbon dioxide, sulcatone, as well as lactic and ketoglutaric acids.

But then, is the case of people who naturally have a lot of skin fatty acids hopeless? Well, the answer tends to be negative, because these fatty acids are produced by the skin microbiota. Just as in certain pathologies, a transfer of microbiota from an individual rarely attacked by mosquitoes would be an interesting way to protect the "mosquito magnets"...