How larvae leap long with no legs

Science News looks at high-speed photo research that reveals how a gall midge larva can leap up to 36 times its body length without any legs:

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.”

The larval jumps filmed were too great for a tiny larva’s muscles, Wise, Patek and colleagues concluded. Blobby little larvae were flipping themselves around with power equal to, or greater than, the oomph of high-power vertebrate flight muscles.

For small animals with constraints on muscles, “it actually works better to put energy into a spring,” Patek says.

Microscope images revealed hairlike structures on the larval surfaces that touched, suggesting that the tiny projections might stick together as type of latch. Such structures could inspire new types of adhesives, Patek says.

Patek had first recognized the latch-and-spring system in mantis shrimp, which throw punches so furiously they can smash aquarium walls, and then in a trap-jaw ant with killer jaws that spring shut in an instant.