Insect Uses Mechanical Gears In Legs To Jump. Yes, Really: Tiny, Incredible Bug Evolved To Have Toothed Gears Before Man

A jumping insect has gears, a new report reveals. The research shows that gears, which have been previously thought to be a man-made invention, also evolved in nature.

The planthopper, Issus coleoptratus, has gears on its hind legs that allow it to jump extremely fast. After much difficulty, scientists finally verified that the tiny insect can jump so far because of even-tinier interlocking gears that allow it to synchronize its legs.

Nature beat humans to inventing gears, apparently-or, more simply, man and nature converged on the same principle. It's a rare case of synchronicity.

"To the best of my knowledge, it's the first demonstration of functioning gears in any animal," said study researcher Malcolm Burrows, who is emeritus professor of neurobiology at the University of Cambridge in the United Kingdom.

Each planthopper leg sports a curved strip of 10 to 12 gear teeth that attach to the trochantera on the insect's legs. These structures were described in 1957, but no one had demonstrated that the gears were functional, Burrows said.

The new study, published in "Science", shows that the planthopper, a tiny insect a bit bigger than the flea, can jump with an acceleration of 200 Gs. This is a level close to the highest that's ever been survived by a human.

To conduct the study, scientists put the planthoppers on their backs on sticky wax, then rubbed their tummies gently to prompt them to jump. The researchers used a high-speed camera and a microscope to capture the bugs' legs wheeling in action...and found that they did, well, sort of wheel. As in, there were gears churning. Literally.

The bugs have toothed gears at the base of their hind legs. The planthopper's gears inter-mesh to synchronize the timing of each limb's release as they jump.

Neurobiologist Malcolm Burrows and engineer Gregory P. Sutton, both of the University of Cambridge, conducted the study.

"It's remarkable that these gears look so similar to the gears man has designed, even the individual teeth are so similar," Burrows said.

The gear mechanism ensures that the legs are always locked together and fire at once, which allows the insects to go farther and faster.

If the gears were not synchronized, the bug's body would spin instead of going straight forward.

"If there were to be a slight timing difference between the legs, then the body would start to spin," Burrows said.

Sure, many animals can jump-but precious energy is wasted on motion that rotates, rather than leaps straight ahead.

The gears function much like the string on a bow, propelling them forward, Burrows explained. "You suddenly let go and the arrow goes much faster than if you were to throw it directly," he said.

The planthoppers also have gear strips that allow them to land near the base of their hind leg. The landing strips, which have about ten teeth each, molt away in adulthood-much like training wheels on a bicycle.

The scientists are not yet sure how the gears evolved, but speculate that they may have first been akin to smaller bumps within the legs, and they then grew larger until they became full-fledged teeth.