Why do mosquitoes bite people | EOS Science

dengue mosquito Aedes aegypti It is found mainly in tropical and subtropical regions and transmits dengue fever, yellow fever, and Zika virus, among others. It mainly stab people. Female mosquitoes bite, males do not.

Mosquitoes find vertebrates via carbon dioxide, body heat, moisture, and visual contrast. What was not known was how they distinguished their favorite host, humans, from other animals.

It has now shown that human scent activates specific regions in the brains of dengue mosquitoes. Those parts of the brain do not or hardly interact with the smells of other animals.

The scents of humans and other animals contain many of the same components, but the proportions differ. The human scent contains an astonishing amount of sulpton, geranalacetone, acetoin, and long-chain aldehydes. Mosquitoes detect chemical signals volatile with nerve receptors in their antennae and mouthparts.

wind tunnel

One part of the mosquito’s brain reacts particularly strongly to human odor. This is controlled by long-chain aldehydes, according to experiments the team conducted in a wind tunnel, among other things. Thus, mosquitoes can reliably separate human and animal odors through a simple neural code.

Most people think of sweat when they think of human body odors. But the important perfume for mosquitoes comes from sebum. Hair follicles secrete this sebum and play a role in protecting our skin. Sulcatone, geranylacetone, and decanal are oxidation products of squalene and sabic acid, which are unique to human sebum.

The composition of sebum is typical for species. We produce from it in a resting state as well as when we are active. This makes it a reliable target for mosquitoes hunting for humans. The findings may be an important step forward in the prevention of tropical diseases.