What attracts mosquitoes to people?/ Four things you should know

2023-08-16 12:12:00, Lifestyle CNA

What attracts mosquitoes to us? Some factors like the carbon dioxide we exhale through breathing, visual stimuli (colors like black and red). While more closely body heat and sweat. And of course our scent: mosquitoes that specialize in biting humans, such as Aedes aegypti, recognize it accurately. Caroline McBride of Princeton University has noticed that they correctly identify the mixture of odorous substances that characterizes us from those of other animals. In this process, 2 nerve centers (glomeruli) in their brain are involved.

1. Manipulating viruses

Some viruses make us more attractive to mosquitoes. A recent study has noted that the Zika and Dengue viruses, responsible for the diseases of the same name, change human body odor to attract Aedes mosquitoes. Scientists have isolated an odorous molecule, acetophenone, most common in the skin of infected mice and humans and attractive to A.aegypti. Produced by bacteria of the genus Bacillus present on the skin: they multiply in those who are infected because the level of a protein that controls them drops.

2. Pregnant women and twins

Other conditions can also affect it. In addition to the viral pathologies described above, malaria also makes them more attractive to mosquitoes, which carry the plasmodium responsible for the disease. Some studies show that pregnant women are a target, perhaps due to increased metabolism that brings more CO2 emissions and heat, or a change in body odor. Then there are individual variations in scent, linked to genetics. A study found that identical twins attract mosquitoes in the same way.

3. No beer

No food that is supposed to keep mosquitoes away has stood the test of science. Instead, something seems to attract them: beer, documented in several studies. One was conducted by researchers from France and Burkina Faso. After drinking 1 liter of beer each, the volunteers became more attractive to Anopheles gambiae mosquitoes (which cause malaria). Researchers have ruled out an increase in temperature or CO2 emissions. They assume that there is a difference in odorous substances.

4. They are attracted by sweat

If you're looking for an excuse not to exercise as much over the summer, Florida International University's Matthew Dexhanors study may provide one. The researcher has proven that mosquitoes are able to identify the substances present in our sweat. He saw how genetically modified mosquitoes, in which a receptor in the antennae had been rendered inactive, were not sensitive to the lactic acid present in sweat. And they were no longer attracted to volunteers' arms or sweaty clothing./ Adapted from CNA