A new study led by scientists at the University of Washington indicates that mosquitoes are attracted to certain colors, including red, orange, black, and cyan. In contrast, these insects tend to ignore green, purple, blue, and white.
Researchers believe this helps explain how mosquitoes locate hosts, as human skin emits a strong orange-red "signal" to the eyes of mosquitoes, regardless of overall skin color.
"The mosquitoes seem to use smells to help them identify what is nearby, like an enticing host. When mosquitoes detect certain compounds such as carbon dioxide from our breath, that smell stimulates their eyes to look for specific colors and other visual patterns associated with a potential host and move towards it," said senior author Jeffrey Riffell, a biology professor at the University of Washington.
The findings reveal how a mosquito's sense of smell influences its response to visual signals. The researchers stated that knowing which colors attract hungry mosquitoes and which do not could aid in developing better repellents, traps, and other methods to keep mosquitoes away.
Riffell said, "One of the most common questions I get is, 'What can I do to prevent mosquitoes from biting me?' I would say there are three main signals that attract mosquitoes: your breath, sweat, and skin temperature. In this study, we found a fourth signal: the color red, which can be found not just in your clothing but also in everyone's skin."
It doesn't matter what your skin color is; we all emit a strong red signature. Reducing those attractive colors in our skin or wearing clothing that avoids those colors may be another way to prevent mosquito bites.
Researchers do not know if mosquitoes perceive colors in the same way our eyes do, but the most preferred colors by mosquitoes after smelling carbon dioxide—orange, red, and black—correspond to longer wavelengths of light.
Beyond skin color, human skin also emits a long-wavelength signal in the red-orange range. When scientists used filters to remove long-wavelength signals or had researchers wear green gloves, mosquitoes equipped with carbon dioxide no longer moved towards the stimulus.
Experts say that further research is needed to determine how visual signals and other odors—such as skin secretions—help mosquitoes target potential hosts from a distance, according to the British newspaper Daily Mail.
