Mosquitoes are no suckers when it comes to blood

According to Florida University entomologist Professor Jerry Butler mosquitoes have an amazingly sophisticated sense of smell which allows them to detect minuscule amounts of chemicals transferred from the human body into the air. The mosquitoes track their victim from molecule to molecule along the invisible trail of these chemicals.

He says that they look for chemicals — like vitamin B or cholesterol — that the human body produces. And, the more of these substances a body produces the more attractive it is to a mosquito and more likely to be bitten. If your blood sends out the right signals a mosquito will findyou.

Butler says that the mosquitoes can home in on their intended victim from as much as 65 km away. Among more superficial things which appear to attract mosquitoes is sweat in which bacteria has had a chance to grow. Perfumed creams and moisturisers are apparently another mosquito friendly signal. Apparently a Spartan soap and water bathing regime is one way of making yourself less attractive to the predatory insect world.

He says that in experiments where a group of subjects were exposed to a large number of mosquitoes, the results were dramatic. He said: One person that’s repellent may get one mosquito bite whereas the highly attractive person in the group may have several hundred bites.’ But Butler’s research did not involve subjecting large groups of people to the consequences of mosquito bites. His findings are based on an olfactometer’ – a device he built which measures mosquitoes’ preferences for different odours. The device contained small plates of blood and other substances said to drawmosquitoes. These plates were covered by a thin membrane to mimic human skin. When a mosquito pierced the membrane a computer recorded the strike.

Butler hopes that his research will be a major contribution to the effort to protect from diseases like malaria and yellow fever which are carried by mosquitoes. The Florida University professor informed: If you can drop the feeding rates below some set ratio, somewhere around a 100-to-1, there wouldn’t be enough infected mosquitoes to transmit it and the disease transmission would collapse.’

Butler’s research is yet in its early stages. Locating what blocks a mosquitoes’ sense of smell would be the central to the success of this system of dealing with mosquito borne disease.