Raindrops Don’t Swat Down Mosquitoes

A fat raindrop falling onto a mosquito should have the impact of a bus running over a human. But the mosquito’s rugged construction helps it survive collisions with even the largest raindrops, report a team of engineers and biologists at the Georgia Institute of Technology in Atlanta online this week in the Proceedings of the National Academy of Sciences.
Mechanical engineer David Hu and colleagues subjected Anopheles mosquitoes to artificial rain, placing the mosquitoes in a mesh-covered acrylic cage and then shooting jets of water into the cage to simulate raindrops falling. The team then filmed the impacts with a high-speed video camera. The videos showed that the mosquitoes would pitch, yaw, or roll to deflect the blows; they survived even direct hits without falling more than about 20 body Lengths. Hu and his colleagues hypothesized that due to the insects’ low mass, the raindrop loses very Little speed and momentum upon encountering the mosquito and thus imparts very little force to it. The mosquitoes’ ability to withstand the impacts may also be due to their exoskeletons, the hard outer covering that protects the inner organs. http://scim.ag/rainmos