Hopping into the record books: Philaenus spumarius can leap as high as 70 cm, or more than 100 times its body length – the equivalent of a human jumping over the Great Pyramid from a standing start.
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PARIS: Scientists said Monday they could explain how the froghopper, an insect that is the world's champion jumper, achieves its extraordinary spring.
Philaenus spumarius can leap as high as 70 cm, or more than 100 times its body length – the equivalent of a human jumping over the Great Pyramid from a standing start.
Massive G force
To do this, the creature attains an initial acceleration of 4,000 metres per second. The gravitational force on its body at this point is 400 G, or 80 times that exerted on an astronaut being launched into orbit.
How the froghopper does this trick has been something of a mystery. Fleas can also jump extremely high but they are 60 times lighter, which means that a froghopper must have some special trick.
The answer, says University of Cambridge, in England, zoologist Malcolm Burrows, lies in a bow-like structure in the insect's internal skeleton, located between its hind legs and wings.
Like an archer tensing his weapon, the bug contracts its muscles to draw back this so-called pleural arch and then releases the stored energy in one go, like a catapult.
Catapult structure
The pleural arch is a composite structure, comprising layers of hard cuticle and a rubbery protein called resilin, which has extraordinary elastic powers that scientists are trying to synthesise for commercial use.
The device is so remarkable that the froghoppers are able to keep the arch in a bent "ready position", so that it can jump at a moment's notice. As Burrows and his team report in the open-access journal BMC Biology, it can be flexed repeatedly, without damage to the bow or the insect's body.
Froghoppers are also called spittlebugs, because they emerge from nymphs that are bathed in protective foam, sometimes known as cuckoo spit, that hangs from foliage. The species is widespread in temperate climates in Europe and North America.
