After much guesswork about why some mosquitoes bite certain people more than others, science has reached a clearer conclusion. The amount of carboxylic acid produced by the skin seems to shape how attractive a person is to these insects. People who emit higher levels of this compound wear an odor that acts like a mosquito magnet, while those with lower production can slip past unnoticed.
The core finding comes from two Rockefeller University researchers in New York, Leslie Vosshall and María Elena de Obaldia. Their work appears in a study published in Cell and settles a host of popular theories about what draws mosquitoes, many of which lacked solid evidence.
Researchers demonstrated that these skin-emitted acids form a scent profile that can be incredibly alluring to mosquitoes. The molecules vary from person to person, creating a personal scent signature that might explain why some individuals attract more bites than others.
Mosquitoes smell their favorite human
There is a very strong link between high levels of these fatty acids on the skin and becoming a magnet for mosquitoes, according to Professor Vosshall.
64 volunteers wore stockings on their arms
The discovery arose from three years of experiments. Sixty-four volunteers wore nylon stockings on their forearms so the stockings could pick up the volunteers’ skin molecules. Mosquitoes were exposed to 2,300 different tests, each showing a pair of stockings to determine which scent drew them more strongly.
The tests used aedes aegypti, a major vector for Zika, dengue, yellow fever, and chikungunya, to observe how insects navigated tubes and moved toward or away from scents and sources.
Subject 33 stood out by a wide margin. This volunteer received four times as many insect visits as the next most attractive participant, and vastly more than the least visited one. Samples during the trials were anonymized so the experimenters did not know who was wearing which stocking. Yet a pattern emerged around Subject 33: the bugs seemed to swarm to that scent almost immediately after the tests began.
Uncovers the mystery of selective pecking
In light of these results, scientists analyzed a range of volunteers to identify what set them apart. They used chemical analysis to examine fifty molecular compounds found on the skin. The analysis showed that volunteers who attracted more mosquitoes produced noticeably higher levels of carboxylic acids than others.
Mosquito biting a human
These substances are part of a microbial process on the skin that creates the body odor common to all people and is unique to each individual.
The finding opens the door to designing mosquito repellents that reduce the presence of these acids or alter the skin bacteria responsible for producing the distinctive odor in every person.
Although the original experiments focused on the species mentioned earlier, the researchers believe other mosquito species would behave similarly when faced with variations in skin chemistry.
Attribution: findings supported by data reported in a peer reviewed article with detailed methodology and results.
This research offers a practical pathway to reduce bites by targeting the skin chemistry that mosquitoes use to pick their targets, potentially leading to new products that mitigate the attraction signals produced by humans.
This work aligns with broader inquiries into how microbial communities on the skin influence human-scent signals and how these signals steer insect behavior.
Notes from the study indicate that the observed patterns held across expanded participant groups beyond the initial cohort, reinforcing the notion that skin chemistry is a key driver of mosquito preference. Further work may explore how diet, hygiene, and environmental factors interact with these chemical signals.
— End of summary of the reported study —