WASHINGTON — What does a tiny fruit fly have in common with an F-22 Raptor fighter jet? More than you might think.
Scientists using video cameras to track a fly's aerial maneuvers found that the insect employs astonishingly quick banked turns to evade predators, much like the ones executed by a fighter jet to elude an enemy.
Their study, published on Thursday in the journal Science, shows that fruit flies are able to change course in less than a hundredth of a second.
The fact that flies are airborne acrobats shouldn't surprise anyone who has ever missed one with a flyswatter. To see exactly how they do it, researchers at the University of Washington synchronized three high-speed cameras operating at 7,500 frames a second. They tracked the wing and body motions of the fruit fly species Drosophila hydei, which is about the size of a sesame seed, inside a cylindrical flight chamber after the insects were shown an image that suggested an approaching predator.
The flies produced impressive escape responses, almost instantaneously rolling their bodies like a military jet in a banked turn to steer away. While executing the turn, the flies showed that they could roll on their sides by upwards of 90 degrees, sometimes flying almost upside down.
"They generate a rather precise banked turn, just like an aircraft pilot would, to roll the body and generate a force to take them away from the threat," said University of Washington biologist Michael Dickinson, who led the study.
The fly flaps its wings about 200 times a second, and in almost a single wing beat it can reorient its body to maneuver away from the threat and continue to accelerate.
"I suspect that these are very ancient reflexes," Dickinson said. "Very shortly after insects evolved flight, other insects evolved flight to eat them. Circuits for detecting predators are very, very ancient. But this one is just being implemented in a high-performance flight machine."
