Correct answer: 1, yes, you’ve become a threat.
With winter drawing to a close, it's a good time to review your mosquito strategy. However insignificant, these parasites have the amazing power to ruin a perfectly pleasant dinner. You can always bring out the heavy artillery by covering yourself in bug spray, lighting a few candles – despite their narrow radius of action – or mixing up some sort of home remedy that may or may not actually work. Or you can resign yourself to shooing them away or half-heartedly trying to kill them, one by one. But that’s all about to change! This year you will swat at them with ever greater fervor, knowing that your gesticulations are not in vain. A team of researchers from the University of Washington has just shown that mosquitoes learn to associate the vibrations caused by our waving hands with our odor after around 15 minutes of playing hard to get with us. This makes them think we’re a threat so they go after other bodies that may have a less pleasant fragrance but are at least less threatening. So in the end, we’ll have to wave our hands around for a quarter of an hour – and it’s every man for himself.
This theory is indeed backed by serious research, which could one day lead to new ways of protecting humans from disease-carrying mosquitoes. These parasites are in fact the deadliest animal on Earth – they kill more than 700,000 people every year. As part of a study to learn more about what attracts mosquitoes, the University of Washington researchers exposed a sample group of these insects to various odors in a vortex mixer that creates vibrations similar to those created by a swatting hand. After 15 minutes, they learn to seek out a new odor rather than going back to the first one, no matter how appetizing. And they remember which odor to avoid for at least 24 hours.
But the researchers went further. They wanted to understand how a mosquito manages to determine which of the 200 chemical compounds that make up a human’s odor signature are the “right ones”. Through a number of experiments, they identified the insect’s dopamine levels as one of the key factors in its decision-making process. This neurotransmitter also comes into play in learning and memory among humans, flies and other animals. By gaining insight into how mosquitoes process information and select their host, experts may someday be able to develop more targeted approaches to controlling the spread of disease.
Article in Current Biology