Every day we are bombarded with masses of sometimes contradictory information on pressing issues. In this feature, a WUR scientist gives you something to hold on to. What are the facts of the matter? Every question makes you a little wiser. Do you dare to ask yours? Email us at email@example.com
That irritating whine keeps you awake at night but as soon as you switch the light on, the bloodthirsty creature is nowhere to be seen. Strange, because aren’t mosquitoes attracted to light?
No, says Jeroen Spitzen, a mosquito researcher at the Entomology lab. ‘Mosquitoes are attracted to carbon dioxide (CO2) in the air we breathe out. When they get closer to us, they follow heat and body odour.’ Our body odour is determined by the bacteria on our skin, says Spitzen. ‘That depends on your genetic predisposition and/ or your lifestyle. There are studies, for instance, that show that people who have been drinking beer are more attractive to mosquitoes. That is probably because their body odour and breath are changed by the process of breaking down alcohol.’
So some people really are more attractive to mosquitoes than others, but ‘sweet blood’ is a myth, says Sptizen. ‘In the sense that sugar doesn’t play a role in it. But there is a kernel of truth in it. The composition of our blood is a factor in our body odour, even though we still don’t quite know how that works. Some species of mosquito have certain preferences because they can lay more eggs with “good blood”. That’s why one person can be bitten to death while the person sleeping next to them is left in peace.’
Sweed blood is a mythJeroen Spitzen, a mosquito researcher at the Entomology lab.
Spitzen thinks the best way to solve the mosquito problem is to tackle it at source. ‘Most of the problems are caused by mosquitoes that hatch out close to your house. So be alert to water in buckets, watering cans or flower pots, and empty them regularly. And of course you can also keep mosquitoes out with screens or a bed net.’
A summary of how to fend off mosquitoes, then: empty the watering can, install screens and pick a partner who is a mosquito magnet.
Participate in human research with non-infected malaria mosquitoes? PhD candidate Marieke de Swart is still looking for men who want to participate. More info, see www.bit.do/bloodandsweat