Mosquitoes evolve to ensure they can always smell humans

By Alice Clifford via SWNS

Mosquitoes have evolved to ensure that they can always smell humans, reveals a new study.

Receptors in mosquitoes’ antenna can detect the smell of humans but even when they were removed, the pesky insects can still find us.

Dr. Margo Herre, a scientist at Rockefeller University and one of the authors of the study, said: “Mosquitoes are breaking all of our favorite rules of how animals smell things.”

In most animals, humans included, specific neurons in the nose can detect certain smells. When you lose one of them, you lose the ability to smell the specific smell it reacts to.

Leslie Vosshall, a professor at Rockefeller University and a senior author of the paper, said: “If you're a human and you lose a single odorant receptor, all of the neurons that express that receptor will lose the ability to smell that smell.”

The research, published in the journal Cell, shows that this is not the case with mosquitoes.

The study found that the neurons used to find humans are stimulated not just by the human smell but by another chemical in mosquitoes called amines.

Having more than one stimulant means that if one is destroyed the other can kick in to help find their target. This co-expression of receptors acts as a fail safe for mosquitoes.

By looking specifically at isolated nuclei, instead of the entire cell, scientists discovered how common this is in mosquitoes.

Vosshall said: “You need to work harder to break mosquitoes because getting rid of a single receptor has no effect.

“Any future attempts to control mosquitoes by repellents or anything else must take into account how unbreakable their attraction is to us.”

Graduate student Olivia Goldman said: “The result gave us a broad view of just how common co-expression of receptors is in mosquitoes.”

This doesn’t just happen with mosquitoes. A research group, led by Christopher Potter at Johns Hopkins University, reports that fruit flies have the same ability.

Prof Vosshall said: “This may be a general strategy for insects that depend heavily on their sense of smell.”