Humming away right before a fatal swat from your hand, these needles of the sky seem to be always just beyond reach. But new research is uncovering how these pesky thieves sneak away with their crimson cargo—and how we might get better at fighting the scourge.
Some mosquitoes are the size of paperclips and weigh only a couple milligrams. Even with bellies full of blood, they're difficult to detect. But other insects, like fruit flies, also seem dainty. So why are they easier to feel in action?
Scientists at the University of California, Berkeley, and the Netherland's Wageningen University teamed up to investigate the behavior of these vexatious vectors using super-slow motion footage.
By observing hundreds of specimens of Anopheles coluzzii mosquitoes with a high-speed camera, the scientists found that mosquitoes start flapping their wings about 600 times a second in preparation for takeoff. Then, they gently push off into the air with their spindly legs, levitating themselves to safety.
By the time you notice you've been bitten, it's too late.
"They push off so softly that you can never detect them" says lead author Florian Muijres. "It's a very challenging thing to do." By contrast, the team found, fruit flies jump up and frantically beat their wings in a bumbling technique that betrays their location.
"Instead of going fast, [mosquitoes] take their time, but they accelerate the entire time so that they reach a final velocity pretty much the same as fruit flies," coauthor Sofia W. Chang told Berkeley News. "That is something that might be unique to mosquitoes, and maybe even unique to blood feeders."
The study's results may be useful in the future for managing mosquito-borne illnesses, says Ryan Carney, an emerging explorer and assistant biology professor at the University of South Florida. The A. coluzzii mosquitoes used in this experiment were clean and sterile, but in the wild, they can carry malaria.
From here, it might be worth investigating flight dynamics in Aedes aegypti and Culex mosquitoes, which can carry Zika and West Nile virus, respectively, Carney says.
And finding ways to combat mosquitoes feels even more pressing in the wake of this year's particularly intense hurricane season.
For instance, when Hurricane Maria ripped through Puerto Rico, strong winds and flooding wiped out most of the area's mosquito population at first. But the storm left behind pools of stagnant water that turned the U.S. territory into a mosquito paradise, and thousands of residents are still living without dependable roofs, windows, and air conditioning.
If scientists are better able to understand how mosquitoes fly, they might be able to help design more efficient traps that can take care of large populations.
"The more you know," Carney says, "the more we can do with that information."