At the same time, mosquitoes ignore other colors, such as green, purple, blue, and white.
The researchers believe the findings help explain how mosquitoes find hosts, as human skin, regardless of overall pigmentation, emits a strong orange-red “signal” to their eyes.
Senior author Jeffrey Riffell, Professor of Biology at varsity said: “Mosquitoes seem to use smell to help them distinguish what’s nearby, like a host to bite.
He added: “When they smell specific compounds, like CO2 from our breath, that scent stimulates the eye to scan for specific colors and other visual patterns, which are related to the potential host. capabilities and towards them.
The results, published in the journal Nature Communications, revealed how a mosquito’s sense of smell – known as olfaction – affects how mosquitoes respond to visual cues.
Knowing which colors attract hungry mosquitoes and which don’t, can help design better repellents, traps, and other methods to keep mosquitoes out.
Before that, the three main signs that attracted mosquitoes were breath, sweat, and skin temperature.
“In this study, we found a fourth sign: red, not only on your clothes, but found on everyone’s skin. Your skin color doesn’t matter, all of us. all radiate red signature health,” Riffell said.
“Filtering attractive colors on our skin, or wearing clothing that avoids those colors, could be another way to prevent mosquito bites.”
In their experiments, the researchers tracked individual mosquitoes in miniature test chambers, into which they sprayed specific odors and presented different types of vision — such as a colored dot. or a delicious human hand.
Without any odor triggers, mosquitoes largely ignore a dot at the bottom of the chamber, regardless of color. After a stream of CO2 enters the chamber, the mosquito continues to ignore the dot if it is green, blue, or purple. But if the dot is red, orange, black, or cyan, the mosquito will fly towards it.
When Riffell’s team repeated the chamber experiments with the human skin pigment tag — or the researcher’s bare hands — the mosquitoes flew toward the visual stimulus again only after CO2 was sprayed into the chamber.
“These experiments point to the first steps that mosquitoes use to find a host,” says Riffell.