Mosquitoes are attracted to three basic signs: breath, sweat and skin temperature. However, scientists have recently added to this list the red colour that every person’s skin radiates to these insects. There is good news: there are clothes that can make this shade less attractive.
Specialists from the University of Washington found out that mosquitoes are especially willing to fly to people dressed in red, orange, black and blue colours. At the same time, insects tend to ignore green, purple, blue and white.
For the experiment, scientists monitored the behaviour of female Aedes aegypti mosquitoes, which transmit yellow fever, dengue fever, chikungunya and Zika viruses. The insects were kept in miniature chambers where they were sprayed with different odours and shown different pictures, such as a human hand or just a white dot.
Without any odours, the mosquitoes ignored all the images. After spraying CO2, the mosquitoes continued to ignore the dot if it was green, blue or purple in colour. But if the dot was red, orange, black or blue, the mosquitoes flew towards it.
How it works:
CO2 from a person’s breath stimulates the mosquitoes’ eyes to scan for certain colours and other signs that are associated with their potential prey. Olfaction affects how they respond to visual cues.
Experiments with coloured dots have shown that mosquitoes’ eyes prefer certain wavelengths in the visible spectrum after smelling CO2. Study co-author Jeffrey Riffel noted that this is similar to what happens to a person when he hears the smell of coffee or buns on the street. He starts looking for a coffee shop or bakery.
The scientists’ discovery could be useful for developing effective repellents, traps and other methods of insect defence. However, the scientists noted that more research is needed because other mosquitoes may have other “colour preferences”.
Prepared by Mary Clair
