Beating the bite of mosquitoes this spring and summer could hinge on your attire and your skin. New research indicates that a common mosquito species — after detecting a telltale gas that we exhale — flies toward specific colors, including red, orange, black and cyan. The mosquitoes tend to ignore other colors, such as green, purple, blue and white. The researchers believe these findings help explain how mosquitoes find hosts, since human skin, regardless of overall pigmentation, emits a strong red-orange ‘signal’ to their eyes.

«Mosquitoes appear to use odors to help them distinguish what is nearby, like a host to bite,» said senior author Jeffrey Riffell, a UW professor of biology. «When they smell specific compounds, like CO₂ from our breath, that scent stimulates the eyes to scan for specific colors and other visual patterns, which are associated with a potential host, and head to them.»

The results, published Feb. 4 in Nature Communications, reveal how the mosquito sense of smell — known as olfaction — influences how the mosquito responds to visual cues. Knowing which colors attract hungry mosquitoes, and which ones do not, can help design better repellants, traps and other methods to keep mosquitoes at bay.

«One of the most common questions I’m asked is ‘What can I do to stop mosquitoes from biting me?’» said Riffell. «I used to say there are three major cues that attract mosquitoes: your breath, your sweat and the temperature of your skin. In this study, we found a fourth cue: the color red, which can not only be found on your clothes, but is also found in everyone’s skin. The shade of your skin doesn’t matter, we are all giving off a strong red signature. Filtering out those attractive colors in our skin, or wearing clothes that avoid those colors, could be another way to prevent a mosquito biting.»

In their experiments, the team tracked behavior of female yellow fever mosquitoes, Aedes aegypti, when presented with different types of visual and scent cues. Like all mosquito species, only females drink blood, and bites from A. aegypti can transmit dengue, yellow fever, chikungunya and Zika. The researchers tracked individual mosquitoes in miniature test chambers, into which they sprayed specific odors and presented different types of visual patterns — such as a colored dot or a tasty human hand.

Without any odor stimulus, mosquitoes largely ignored a dot at the bottom of the chamber, regardless of color. After a spritz of CO₂ into the chamber, mosquitos continued to ignore the dot if it was green, blue or purple in color. But if the dot was red, orange, black or cyan, mosquitoes would fly toward it.

Story Source:
Materials provided by University of Washington. Original written by James Urton. Note: Content may be edited for style and length.