"It has to store energy in advance of being able to jump and what it has is two huge muscles in its body," he said. "It invests 11 percent of its body mass in these two muscles."
These muscles, which power the rear legs, are located in the froghopper's chest. As the insect readies to leap, it tucks up and holds its rear legs in a cocked position on a ridge between one part of a hind leg and another. The rear legs stay locked in this position until the jumping muscles load up with enough energy to break the legs free from the ridge, launching the froghopper into the air, explained Burrows.
"When it has enough force it sort of snaps open and it does this incredibly fast," he said. In less than a millisecond, the leg extends and accelerates the body at speeds up to 13 feet (4 meters) per second.
"The catapult mechanism is exactly what we would expect good jumpers with small legs to use, but this is the most spectacular example that I have heard of so far," said Heitler. "Humans probably learned to use catapults a few thousand years ago, but insects like these evolved catapults inside their own bodies hundreds of millions of years ago."
The process of loading up the jumping muscles takes just about a second and the release that sends the froghopper flying through the air happens in a millisecond. To study this action, Burrows used a high-speed video camera capable of shooting 2,000 frames per second. The insect jump takes up two frames of tape.
While persuading the insects to jump in front of the camera proved difficult, "the hardest part was to catch the little guys in the first place because they jump so well," said Burrows.
The next stage in Burrows' research is to attach wires to individual cells in the froghopper's brain to record how the nervous system controls the simultaneous, rapid action of the insect legs.
"I'm trying to understand how these circuits of nervous cells control movements," he said. Since insects have relatively large brain cells and fewer of them than creatures such as humans, they make for simple research models, added Burrows.
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