A study of 119 people finds that each species of mosquito has its own preferences when it comes to biting

A new study involving 119 participants has revealed that each species of mosquito has its own distinct preferences when it comes to biting humans. Conducted by researchers at the Florida International University (FIU) in the United States, the study exposed volunteers to three of the world's most dangerous mosquito species, Aedes aegypti, Aedes albopictus (also known as the Asian tiger mosquito), and Culex quinquefasciatus (the house mosquito), and found that none of the participants was attractive to all three species. Instead, each mosquito species exhibited unique preferences based largely on the chemical composition of individual bodies. The findings, published in the journal iScience, suggest that understanding these differences could lead to the development of more effective, species-specific repellents. Since each mosquito species interprets human scent differently, identifying the components of odor that attract or repel them might help create targeted strategies against diseases transmitted by these insects. Matthew DeGennaro, a neurogeneticist leading the research team at FIU’s Institute for Molecular Sciences, noted that isolating the human odor components that influence mosquito behavior could pave the way for new approaches to combating vector-borne illnesses. The three mosquito species studied were chosen because they are responsible for spreading a range of serious diseases, including yellow fever, dengue, Zika, and West Nile virus. The study, led by doctoral student Kaylee Marrero, marks the first time researchers have directly compared how multiple mosquito species react to the same individuals. Marrero expressed surprise at the results, noting that she did not expect the species to show such distinct preferences. She emphasized that each species used a different microbial signature as a cue, with varying factors influencing their attraction or avoidance. Aedes aegypti, which feeds during the day, showed a preference for individuals who did not use added fragrances and whose skin lacked certain volatile compounds. These mosquitoes also displayed a slight tendency toward men over women. In contrast, Aedes albopictus, the Asian tiger mosquito, was drawn to higher levels of ketones and plant-derived volatile compounds naturally secreted by human skin. Like Aedes aegypti, this species also feeds during daylight hours. Culex quinquefasciatus, the house mosquito, which typically feeds at dusk, focused instead on the skin microbiome, the ecosystem of bacteria, fungi, and other microbes that live naturally on human skin. Some bacterial families acted as signals encouraging feeding, while others deterred the mosquitoes. This finding highlights the complexity of human-mosquito interactions and suggests that the microbiome plays a crucial role in determining which individuals are more likely to be bitten. The human body emits a complex mixture of over 1,000 volatile organic compounds, many of which remain unidentified. Rather than agreeing on which individuals were more attractive, each mosquito species preferred a different subset of participants, indicating that these insects have developed varied methods of detecting humans. To uncover these patterns, researchers collected samples of both odor and skin microbiota to determine which compounds and bacteria were present and at what concentrations. DeGennaro explained that the data aligned perfectly with variations in skin bacteria and odors. He concluded that human skin microbiomes define our olfactory profiles, and each mosquito species found its own way to interpret these profiles. The research aims to contribute to the development of novel repellents tailored to specific mosquito species, offering a potential breakthrough in the fight against vector-borne diseases.