Science

New study reveals how the color of your shirt could attract mosquitoes

New study reveals how the colo...
A new study has found that mosquitoes are attracted to certain colors, like red, when they're ready to feed
A new study has found that mosquitoes are attracted to certain colors, like red, when they're ready to feed
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A new study has found that mosquitoes are attracted to certain colors, like red, when they're ready to feed
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A new study has found that mosquitoes are attracted to certain colors, like red, when they're ready to feed

If you’ve ever been eaten alive by mosquitoes at a barbecue while the person sitting next to you escapes unbitten, the color of your clothes might be to blame. New experiments reveal that certain colors attract hungry mosquitoes while others are ignored, a finding that could be used to design new traps or repellents.

Besides being a nuisance at outdoor gatherings, mosquito bites can transmit diseases like malaria, yellow fever, dengue or Zika. Investigating how the bugs find hosts can inform new protective measures. Previous work has found that mosquitoes are attracted to the odor of carbon dioxide from our breath, and in the new study, researchers at the University of Washington examined how that scent primes them to start looking for food.

The team conducted experiments using female mosquitoes of the common species Aedes aegypti, tracking their responses to visual and olfactory cues in a test chamber. They tested how the bugs responded to dots of different colors on the bottom of the chamber, with or without a spray of CO2.

The team found that mosquitoes would fly towards a dot if it was red, orange, black or cyan, and if it had first smelled CO2. Without the gas, the bugs would largely ignore the dots no matter what color they were. However, they still didn’t care for dots that were green, blue, white or purple, even if they’d been primed to hunt with a spritz of CO2.

“Mosquitoes appear to use odors to help them distinguish what is nearby, like a host to bite,” said Jeffrey Riffell, senior author of the study. “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.”

So why are mozzies attracted to reds and oranges specifically? The team says that human skin, regardless of the shade or pigmentation, gives off a strong red-orange signal to mosquito eyes. In follow-up tests, the researchers used cards of different human skin colors, or a bare hand, and found that again, the bugs would fly towards them only if they smelled CO2 first. If the long wavelengths were filtered out, or the hand was wearing a green glove, the insects went back to ignoring them, even with CO2.

Finally, the team conducted the same experiments on mosquitoes that had been genetically modified. If genes responsible for smelling CO2 or seeing long wavelength colors were edited, the bugs didn’t respond to the visual stimulus, indicating both senses are required to ring the dinner bell.

The team says that future work will investigate other cues, like skin secretions, that might help mosquitoes home in on their host. They also suggest that other species that prey on different animals might have different color preferences.

In the meantime, the work could inform new ways to control mosquitoes and prevent bites – from wearing white to making red, CO2-emitting traps.

The research was published in the journal Nature Communications.

Source: University of Washington

9 comments
9 comments
Norm.Rhett
So they're attracted to cyan, which is described as blue-green, but not to blue or green?
ArdisLille
Why are we just finding out about this now? I should think color would be on the skeeter-researchers list long ago.
guzmanchinky
Oh what an amazing world it would be if we eliminated biting mosquitos.
Christian Lassen
Weird is that they still went after cyan, but not green or blue. Kinda a weird exception there
TechGazer
If the trigger is the red->orange spectrum, then green->purple clothing should be better than white, since those colours would absorb more of the red->orange. If IR is also a trigger, then white clothing would remain cooler. Maybe testing will reveal the optimum colour of clothing to deter mosquitoes. Hmmm, even if it only reduces bites by a fraction of a percent, marketers will push a line of clothing with greatly exaggerated claims.
Rusty Harris
Flowers & bees are the same way. The color is "enhanced" with their eyes.
Greg Welsby
Cyan is light blue or blue green so how is it that cyan is attractive to mosquitoes but blue and green are not?
KaiserPingo
As anyone with some hunting or army background will know, colours are not just colours...
The human eye visible spectrum is a lot different from mosquitos, so that two colours we would percieve as "the same", are completely different colours in the eyes of a mosquito.
This article lacks some background info, that I hope is actually a part of the real rescearch project.
KaiserPingo
White is clearly the reason, that there are no mosquitos in the winter months !
(To US Americans: The above line is a joke. Just to clarify for you).