UW study finds fruit flies duck, dodge like fighter jets
Researchers at the University of Washington flight-tested fruit flies dodging a threat and found the critters executing banked turns at five times their normal speed.
Los Angeles Times
Fruit flies could make some talented fighter pilots. Scientists who had the insects wing it through two laser beams watched the bugs make hairpin turns at blazing fast speeds by banking in the same way as jet fighter planes do.
The findings by researchers from the University of Washington, published in the journal Science, shed light on these tiny critters’ remarkable ability to evade predators (and fly swatters).
Trying to escape a threat, the Drosophila hydei flies turn at a speed five times faster than their normal turning speed, according to the researchers. Instead of turning right or left on the “yaw” axis, like a boat in the water, the flies execute banked turns by rolling and pitching their bodies at the same time, which supercharges their turns.
They can execute such a movement in less than one-hundredth of a second after seeing a threat, the scientists said. That’s 50 times faster than the blink of an eye.
“A lot of other people working in the field ... would not have predicted the fly could rotate itself so quickly,” said study co-author Michael Dickinson, a UW neurobiologist in Seattle.
The scientists watched the flies fly through two crossing laser beams, causing their own shadows to loom large like an impending threat. In response, the flies executed escape maneuvers, which the scientists captured on camera.
Dickinson and his colleagues recorded 3,566 wing beats in 92 separate fruit-fly escapes. To capture such infinitesimally tiny movements, the scientists flooded the flight area with infrared light and used high-speed cameras that took 7,500 frames per second — nearly 40 frames for each wing beat.
Videos showed the flies rolling to one side by 90 degrees or more as they made turns in less than two wing beats.
“We’re very interested in how the brain can control motion on such a fine scale,” Dickinson said.
The scientists were able to calculate mathematical rules governing the flies’ decisions for making banked turns. They then programmed their findings into a larger-scale robotic fly for testing.
The next step, Dickinson said, is to understand the complex neural circuitry, linked to the flight muscles, that makes the flies’ daring maneuvers possible.