Coconut or almond-scented soaps ‘can make you unattractive to disease-carrying insects’

Your soap can make you look hotter to bloodthirsty mosquitoes.

Because researchers have found that some smells can make you a more attractive target for pests.

American scientists found that the bugs were attracted to those using the flower-scented Dove or Simple Truth, but were unnerved by the coconut-scented Native brand.

The results suggest that people who are “extremely attractive to mosquitoes” can become “repellent” by switching soaps, the experts said.

Write in the journal iSciencescientists explained their findings can be used to design artificial mixtures to repel the disease-causing insects.

Researchers put the nylon covers used by study participants in a gauze-covered cup filled with adult female Aedes aegypti mosquitoes — a species known to spread diseases including yellow fever, Zika and dengue. Only female mosquitoes were used because they feed on blood – male mosquitoes, on the other hand, feed exclusively on plant nectar

Virginia Tech University academics analyzed the chemical odors emitted by four participants before and after they washed with Dial, Dove, Native and Simple Truth soaps.

Volunteers washed one arm, rinsed with water alone for 30 seconds, and dried with a paper towel.

The other was washed with the test soap for 10 seconds and rinsed for an additional 10 seconds.

Both arms were then each covered with a nylon cover, repeating the process for each soap.

After an hour, researchers placed the nylon covers in a mesh-covered cup filled with adult female Aedes aegypti mosquitoes — a species known to spread diseases including yellow fever, Zika and dengue.

Only female mosquitoes were used because they feed on blood. Male mosquitoes, on the other hand, feed exclusively on plant nectar.

Fabric covers were also used instead of exposing the volunteers themselves to the insects, to rule out the effects of other important signals for mosquitoes.

Possible effects of other substances in the soaps “has not been considered here and has yet to be analysed,” the researchers said.

Washing with Dove, Dial and Simple Truth increased the attractiveness of some, but not all, volunteers to the mosquitoes, scientists found.

But washing with native soap tended to repel mosquitoes.

“Of the soaps tested here, Dial and Dove increased the overall headspace chemical abundance significantly more than the Simple Truth and Native soaps,” they wrote.

“Native crop hosts were mostly avoided, and significant aversion was observed in the case of the fourth volunteer,” they added.

Native’s relatively repellent effect could be linked to its coconut and almond scent, the scientists said, as there is some evidence that coconut oil is a natural mosquito deterrent.

Benzaldehyde — a compound commonly found in plants with an almond-like scent — was also “most strongly associated with the native soap,” they wrote.

Senior author Dr Clement Vinauger said: ‘It is remarkable that the same individual who is extremely attractive to mosquitoes when unwashed can become even more attractive to mosquitoes with one soap – and then become repellent or repulsive to mosquitoes with another soap.’

Knowing what lures the hungry pests also opens the door to developing better repellents, traps and other methods to keep them at bay.

The study’s co-author, Dr Chloe Lahondere, added: ‘We know that ratios of chemicals are extremely important in determining whether mosquitoes are attracted or repelled.

“Changing the ratio of exactly the same chemicals can lead to attraction, indifference or repulsion.”