Why Different Mosquitoes Prefer Different People

You could be a five-star buffet for one mosquito species and completely invisible to another, and scientists now know why.

A new study from Florida International University (FIU) found that three of the world’s most dangerous mosquito species each hunt humans using a different chemical playbook, zeroing in on distinct compounds in skin oil, sweat, and even the bacteria living on your body.

No single person was equally attractive to all three species, suggesting that each mosquito type responds to distinct human scent cues. Each species seemed to be chasing something different.

“Understanding mosquito attraction is extremely important because every mosquito-borne infection begins with a mosquito successfully finding and biting a host,” Luisa Messenger, a mosquito researcher and professor of public health at the University of Nevada–Las Vegas, who was not involved in the study, told The Epoch Times.

Many people picture mosquitoes as one generic pest, but in reality, there are more than 3,500 species of mosquitoes, and “only a minority of those prefer to bite humans,” Messenger said.

3 of the Most Dangerous Mosquitoes

Researchers tested 119 volunteers against three species responsible for some of the world’s most serious diseases: Culex quinquefasciatus, the most common disease-carrying mosquito and a primary spreader of West Nile virus, also known as the southern house mosquito.

They also tested two Aedes mosquito species: Aedes aegypti and Aedes albopictus, both carriers of yellow fever, dengue, Zika, and chikungunya. Aedes mosquitoes are recognized for their bold white stripes.

Each species seemed to be chasing something different:

Southern house mosquitoes, which bite after dark, tracked people based on their skin’s bacterial makeup rather than the skin itself. Some bacteria made people more attractive, while others seemed to actively repel the mosquitoes.

Aedes aegypti preferred people with little to no added scent, such as perfume or lotion, and skin that was naturally low in certain compounds called cyclic alcohols, monoterpenes, and ketones. It also showed a slight preference for men during the day.

Aedes albopictus, which bites during the day, was drawn to skin compounds that smell like plants—the same types of molecules that give fruit, flowers, and leaves their scent. Human skin releases trace amounts of these, too, through diet, metabolism, and the bacteria living on us.

The researchers said bacteria on the skin could help explain why different people have different skin compounds, although other studies have also pointed to genetics, diet, and lifestyle as factors that influence the scent on people’s skin.

Previous research involving Aedes aegypti found that people who are highly attractive to mosquitoes have higher levels of certain carboxylic acids on their skin, Dr. Luis Marcos, an infectious disease physician at Stony Brook Medicine in New York state, who was not involved in the study, told The Epoch Times.

“This attractiveness can remain relatively stable over several years,” he said.

Your Skin’s Bacteria Do More Than You Think

Human scent is more complicated than most people realize. It’s made up of more than 1,000 different chemicals, and scientists still do not know what most of them do.

For the southern house mosquito, the real target was not the skin; it was the microbes living on it.

Bacteria such as Staphylococcus and Corynebacterium species feed on human sweat and sebum, and as they break these secretions down, they release acids and ammonia. These byproducts act as a scent trail that southern house mosquitoes can follow after dark.

Conversely, a more diverse skin microbiome or the presence of specific strains such as Pseudomonas or certain Micrococcus strains seemed to work in the opposite direction, producing compounds that mask human odors or actively deter mosquitoes.

“It is clear to me now that our skin microbiomes define our human odor signature,” FIU neurogeneticist Matthew DeGennaro, who led the study, said in a statement. “Each species found its own way to decode that signature.”

By understanding these species-specific scent cues, the researchers plan to develop targeted repellents and public health strategies that address the preferences of mosquito species most common in a given area.

Attraction is only one component of disease risk, Messenger said. Whether someone becomes infected also depends on which mosquito species are present, whether they are carrying a pathogen, how frequently they bite, and a person’s existing immunity.

“What this study adds is the recognition that we probably should not think about ‘mosquito attraction’ as one universal phenomenon,” she said.

Factors Known to Increase Mosquito Attraction

Some everyday habits and dietary factors may make your skin chemistry more appealing to mosquitoes:

How Best to Prevent Mosquito Bites

Until species-specific repellents exist, Marcos said the best advice is to use proven preventive measures, as described by the Centers for Disease Control and Prevention. These measures include: