Who do mosquitoes like to bite? Scientists have found the smell of human "greasy molecules"

There have long been theories about who is more likely to be bitten by mosquitoes. A new study finds that the smell favored by mosquitoes is related to the "greasy molecules" in our skin secretions. Another bad news: these blood-sucking robbers will remain loyal to their favorite smells over time.

"If you have high levels of this on your skin, you're going to be the guy who gets bit at the picnic," said study author Leslie Vosshaar, a neurobiologist at Rockefeller University in New York.

To test mosquito attraction, the researchers designed an experiment that pitted people's scents against each other, explained Maria Irina de Obadía, another author of the study, which published its findings Tuesday in the journal Cell.

The researchers had 64 volunteers from Rockefeller University in New York and nearby areas wear nylon stockings on their forearms to imbue them with skin odor. The stockings were individually placed in a trap at the end of a long tube, and dozens of mosquitoes were released.

“They basically flock to the most attractive object,” De Obadiah said. “The results are immediately obvious.”

The scientists held a round-robin competition and finally came up with a surprising gap: the strongest mosquito-attracting physique was about 100 times more attractive to mosquitoes than the last one.

On January 27, 2016, an Aedes aegypti mosquito carrying Zika virus and dengue fever was photographed under a microscope at the Fiocruz Institute in Recife, Pernambuco, Brazil.

The experiment used the Aedes aegypti mosquito, which is known to spread diseases such as yellow fever, Zika virus and dengue fever. Leslie said she hopes to get similar results with other species, but more research is needed to confirm.

Among the most popular subjects, the researchers found a common factor: The skin of mosquito-attracting people was high in carboxylic acids . These "greasy molecules" are part of the skin's natural moisturizing layer, and people produce them in varying amounts, with more carboxylic acids produced as sebum is devoured by millions of beneficial microorganisms on the skin. Large amounts of carboxylic acids give off an odor similar to that of cheese or foot odor, which attracts mosquitoes.

"You can't get rid of these carboxylic acids without compromising skin health," said Wasshall, chief scientific officer of the Howard Hughes Medical Institute, which supports the AP's health and science divisions.

Jeff Riffel, a neurobiologist at the University of Washington who was not involved in the study, believes the research may help find new ways to repel mosquitoes, perhaps by adjusting the skin flora to change this annoying "attractive" smell.

Outdoor Mosquito Repellent

Still, finding ways to repel mosquitoes is not easy, as the creatures have evolved into "lean, mean biting machines." Mosquitoes are extremely sensitive to human odor, which even perfume can't mask, Leslie said.

This study also proves this point: after the researchers edited the genes of these mosquitoes and destroyed their sense of smell, they conducted the experiment again and they still persisted in gathering around the same mosquito-sucking physique.

Zhu Jingning, reporter of Orange Interactive