by Cynthia on 18/06/12 at 9:14 am
As annoying as they are to us, Mosquitoes are evolutionary wonders and perhaps the original Tai Chi masters.
A current article in Science News explains how Mosquitoes survive being hit by raindrops. It’s the equivalent of a human being stuck by a bus and the mosquito keeps flying despite repeated hits during a rainstorm.
Here are some excerpts from the latest article on this research:
New experiments show how the insect’s light weight works in its favor, says engineer David Hu of the Georgia Institute of Technology in Atlanta. In essence, the (relatively) huge, fast drop doesn’t transfer much of its momentum to a little wisp of an insect. Instead the falling droplet sweeps the insect along on the downward plunge. As Hu puts it, the mosquito “just rides the drop.”The trick is breaking away from that drop before it and the insect splash into the ground. Mosquitoes that separate themselves in time easily survive a raindrop strike.
Plenty of lab work has investigated how flying animals recover from disturbances, but there’s little work on raindrops because those collisions are very hard to study, Hu says. To mimic raindrop speed of about 9 meters per second, he and his colleagues tried dripping water off the third floor of a building toward ground-level mosquitoes. “It’s the worst game of darts you can imagine,” he says. “You have no hope of hitting them.”
Finally, Hu sprayed streams of water from a pump at caged lab mosquitoes and then refined the process by spraying mosquito-sized beads. His team found that mosquitoes hit with water survived using an insect version of tai chi: Move with the blow instead of resisting it. A raindrop can reach 50 times the mass of a mosquito, and after colliding, “the mosquito becomes a stowaway,” Hu says.