Two US researchers come up with the explanation after a three-year experiment with dozens of volunteers
After multiple speculations about why the mosquitoes they bite some people and not others, science has just issued its verdict. The amount of carboxylic acid that each individual produces on their skin will determine to what extent their body is attractive to these insects. Who generate higher levels of this compound will give off a certain body aroma and will become a “mosquito magnet”while those who generate less will manage to go more unnoticed by them.
This is the main conclusion of the study that two researchers from the Rockefeller University of New York, Leslie Vosshall and María Elena de Obaldia, have just published. Their results have been published in the journal Cell And they put an end to a whole series of popular theories about what attracts mosquitoes, often without scientific basis of any kind.
Both researchers have managed to show that this type of acid emanating from the skin can create a truly intoxicating perfume for mosquitoes. These substances present in the human organism constitute a group of molecules that each person secretes in different quantities and compositions.constituting a sign of personal identity.
“There is a very, very strong relationship between having large amounts of these fatty acids in your skin and being a magnet for mosquitoes,” said Professor Vosshall.
64 volunteers with stockings on their arms
This result has been discovered after an experiment that lasted three years. The scientists asked 64 volunteers to put nylon stockings on their forearms. in order, in this way, to be able to impregnate them with the molecules of your skin. 2,300 different tests were carried out in which each pair of socks was shown to the mosquitoes so that they could detect their smell and choose some of them.
Mosquitoes were used to carry out this test. Aedes aegyptithe main vector species for Zika, dengue, yellow fever and chikungunyaand observed how the insects flew through different tubes towards one stocking or another.
By far, the volunteer who was most attractive to these mosquitoes was the so-called ‘Subject 33’, who received four times as many visits from the insects as the next rankedand no less than 100 times more than the least visited by them, ‘Subject 19’.
The samples in the trials were not identified, so the experimenters did not know which participant had worn which stocking. Still, they immediately noticed that something unusual was going on in any test involving Subject 33, because the bugs were swooping right onto his tights. “It was evident within seconds of starting the trial,” says De Obaldia.
Immediately afterwards, and in view of these results, the researchers analyzed the different volunteers to find out what differentiated them. They used chemical analysis techniques to identify 50 molecular compounds present on the skin of the participants. It was then that found that the most attractive volunteers to mosquitoes produced much higher levels of carboxylic acid than the others.
This substance is used by skin bacteria to produce the body odor that every human has. and that it is unique in each person.
This discovery opens the door to the manufacture of mosquito repellent products that reduce the presence of these acids or affect the bacteria that produce each person’s body odor.
Although the experiment (which was later extended to more participants, with identical results) was carried out with the aforementioned species of mosquito, the researchers believe that other specimens would have the same behavior.
Reference study: https://www.sciencedirect.com/science/article/pii/S0092867422009278?via%3Dihub
….
Contact of the Environment section: [email protected]