By Susan Milius
No legs? Not a problem. Some pudgy insect larvae can still jump up to 36 times their body length. Now high-speed video reveals how.
First, a legless, bright orange Asphondylia gall midge larva fastens its body into a fat, lopsided O by meshing together front and rear patches of microscopic fuzz. The rear part of the larva swells, and starts to straighten like a long, overinflating balloon. The fuzzy surfaces then pop apart. Then like a suddenly released spring, the larva flips up and away in an arc of somersaults, researchers report August 8 in the Journal of Experimental Biology.
In nature, something has to go wrong for this to happen, says evolutionary ecologist Michael Wise of Roanoke College in Salem, Va. These midges normally grow from egg to adult safely inside an abnormal growth, or gall, that they trick silverrod plants into forming. But as Wise was trying to coax out some still-immature larvae, he realized that the supposedly helpless young — extracted prematurely when they were no bigger than rice grains — could not only vault out of a lab dish but also could travel a fair distance across the lab floor.
To get a better look at the insects’ jumps, he contacted evolutionary biomechanist Sheila Patek at Duke University. “He sees small fast things and thinks of his buddy Sheila,” Patek says. Her lab specializes in resolving never-before-seen subtleties of animal motion, typically using high-speed video. “The truth is, we film for people all the time, and it’s almost never small and fast by our standards,” she says. “But this actually was.”