Researchers test pests’ favourite blood factors
New York’s Rockefeller University told the Australasian Neuroscience Society Meeting in Cairns yesterday that after uncovering the four main ways humans attract mosquitoes, they found that eliminating one of these was not enough to repel the insects.
“The prediction was that carbon dioxide – which we exhale with each breath – would be super important,” Prof Vosshall said. “But the surprise was that even if you make a mosquito that can’t sense carbon dioxide, under the right circumstances they’re just as good at hunting humans.
“Now we’re running through all the different senses mosquitoes have to work out what are the best tricks they use to find us. We need to make a multi-pronged attack.”
Not only will the findings help many more brave the summer nights outdoors without risking itchy welts but an effective repellent would help the 475,000 people killed by mosquito-borne viruses each year. This potential prompted the Bill and Melinda Gates Foundation to back the research.
Prof Vosshall’s laboratory is now testing why certain people are more prone to bites.
By positioning the arms of her research participants next to a cage of mosquitoes, they will record who they swarm to and match the results to the person’s biochemical make-up.
Yet-to-be-published results suggest it is the components of an individual’s blood that motivate a mozzie to munch.
“The favourite idea is that the blood is sweet, or girls are sweet, or type 0-negative blood is bitten more,” she said. “We’ve kept track of all the ideas that are scientifically raised or raised by the general public, and tried to test as many of them as possible.
“It’s not the sugar in the blood, it’s probably not the blood type. It’s probably something about the nutrients in the blood.
“There is something about the different molecules that are floating around in the blood that seem to be very predictive.”