5 September, 2007

Smelling mosquito

Biting mosquito

Mosquitoes do not bite everyone; some people are more prone to get bitten, while others are not interesting for mosquitoes. A general saying is that the bitten people are more delicious. Of course, this is ridiculous.

Researchers have found specific cells in one of the three organs that make up the mosquitoes nose tuned to identify the different chemicals that make up human body odour.
Sweat, for example, simply smells better on certain people, because of the proportions of carbon dioxide, octenol and other compounds that make up body odour.

The way a mosquito smells can help to develop a new generation of repellents that would block the mosquitoes’ nose, which will prevent them from finding humans.

Mosquitoes use three organs to smell and taste:

  • a feathery antenna which can identify a wide range of different chemicals
  • a proboscis used for short-range detection
  • the maxillary palp for longer range smelling.

The tips of the organs that make up the mosquito nose are perforated with thousands of tiny holes that let aromatic compounds to penetrate. Once inside, chemicals encounter the receptors that detect specific molecules that identify potential targets as human.
The maxillary palp contains a series of these highly specialised receptor cells used to detect the different components of human body odour. The hairs are all attached to three neurons:

  • one which is tuned to detect carbon dioxide
  • one which is tuned to detect octenol
  • one which serves to enhance general olfactory reception.

If it possible to block or hyper-stimulate these molecular components in the mosquitoes’ nose, the mosquito would not do nearly as well at finding human prey.

Humans, Nature, Neuroscience