Mosquito species respond to different human scent cues

Three common mosquito species are attracted to people in different ways, with skin bacteria and scent compounds shaping their preferences, ERR reports.

US and Swiss researchers asked 119 volunteers to place their hands in a special tube so they could observe mosquito behaviour and collect bacteria and airborne scent compounds from the skin. To study mosquitoes that are active at night, participants wore nylon sleeves that captured their body odour.

The yellow fever and other virus-spreading mosquito Aedes aegypti showed a slight preference for men: an average of 92% of the mosquitoes flew towards male participants, compared with 87% towards women.

Researchers identified 246 groups of bacteria on participants’ skin, but only one was found on all 119 people. Men had significantly more of certain bacteria that help produce specific scent compounds.

Bacteria on the skin transform sweat and sebum, which are largely odourless, into airborne compounds. This process gives each person a distinctive scent profile, the researchers said.

The study’s key finding concerned Aedes aegypti and Culex quinquefasciatus. Rather than being drawn by a greater number of appealing scents, the mosquitoes found people more attractive when their skin lacked certain repellent compounds, including specific cyclic alcohols and monoterpenes. By contrast, Aedes albopictus was attracted to particular scents, such as ketones.

The findings could help researchers develop more targeted mosquito repellents. The results were published in the journal iScience.