Spittlebug Beats Flea to Become High Jump Champ

November 14, 2008

The spittlebug's only claim to fame has been that it can blow bubbles out of its backside. But we may have to give this little bug more recognition. An international team of researchers has just determined that spittlebugs jump higher than any other creature when body length is taken into consideration.

Spittlebugs beat out fleas for the #1 spot.

To earn nature's high jump champ crown, the tiny insects lept close to 28 inches, or 100 spittlebug body lengths. For comparison, the ability to leap 100 times the height of the average human would enable a jumper to clear many of the nation's tallest buildings.

The bugs protect themselves by whipping up a froth that looks like a gross cross between human spit and latte foam. You usually don't even see the insects themselves, since they hide in blobs of the stuff on your garden plants. Here's what they look like.

The scientists figured out that spittlebugs use a catapult-like mechanism to achieve their jumping prowess. Energy generated by the slow contraction of a huge bank of muscles is stored in an elastic internal structure, then released in less than a millisecond to power the explosive extension of the bug's hind legs.

“They jump like little bullets,” says Steve Shaw, a professor with the Department of Psychology and Neuroscience at Dalhousie University. “It’s a last ditch escape response, otherwise the bug becomes bird food.”

Shaw and Malcolm Burrows, current head of the Zoology Department at the University of Cambridge, spent August afternoons sweeping the long grasses with nets at York Redoubt, the 18th century military fort overlooking Halifax Harbour. They returned to Dalhousie to analyze the specimens they collected.

Shaw examining a spittlebug.

(Credit: Daniel Abriel)

Under the microscope, they could see a stretchy protein also found in the wing-hinges of dragonflies. This protein, called resilin, is set against the spittlebug's hard exterior body armor, which is stiff enough when bent to absorb all the muscle energy, retaining the tension that will power the jump. It's actually similar to the recurved compound bows carried by Genghis Khan’s Mongol cavalry—short, light but powerful weapons that made these mounted archers such a formidable fighting force in the 13th century. Their bows were also made of a composite laminate: most energy was stored by flexing the bow’s hard back of horn or bone, stiff but brittle, while elastic recovery was afforded by animal sinew glued on the front. The Mongol riders could discharge their high-tech weapons while riding at full tilt, making them a highly mobile and deadly mounted archer force not seen before in warfare.

Could this system be adapted as a commercial proposition for human jumpers?

“Well, even if Nike or Reebok found a way to put resilin in shoes for basketball players,” says Shaw with a smile, “the downside would be that they’d go on rebounding forever so never wear out. Like the fabled re-usable match, where’s the money in that?”

A reminder of this film.

Comments

[YuliaRu]

I couldn't find out what's the difference between this "new" study and this: http://news.bbc.co.uk/2/hi/science/nature/3110719.stm
Can somebody explain me? Thank you.

[Jen Viegas]

Good eye in remembering that earlier study, YuliaRu. This latest research was indeed co-authored by Malcolm Burrows, who worked on the Nature paper, mentioned in the BBC news story. Must be a topic he's focused on for a while. This latest study was published recently in BMC Biology.