Image portraying a mythical Issus nymph.

In a fascinating discovery, researchers have found that young planthopper insects (Issus coleoptratus) employ gear wheels in their hind legs to coordinate their movements during high-speed jumps. This unique finding, made by Malcolm Burrows, a University of Cambridge researcher, and his collaborator, engineer Greg Sutton, challenges our understanding of synchronised movement in the animal kingdom.

Previously, it was known that crocodilians have cogwheel valves in their hearts to regulate blood flow. However, the discovery of gears that ratchet together to synchronize movement in an animal is a new development.

Adult planthoppers, on the other hand, do not possess such structures. Instead, the adults use a frictional strategy to ensure synchronised movement. This difference in mechanisms between young and adult planthoppers was first noticed by Burrows, who initially struggled to find research subjects in his own garden. He enlisted the help of his five-year-old grandson in 2010, and together they successfully located the planthoppers in his yard.

The young planthoppers, called nymphs, are capable of jumping about three feet (a meter) and eject themselves into the air at about ten feet (three meters) per second. During a launch, their hind legs move within 30 microseconds of each other, a remarkable display of precision.

The nymphs employ gear wheels-complete with teeth that interlock with grooves-to coordinate their hind legs during these high-speed jumps. However, if a gear wheel in an adult planthopper breaks, it would remain broken for the rest of its life. This could potentially shorten their lifespan due to ineffective escape from predators, as the lack of a replacement mechanism in adults might be the reason for their abandonment of gear wheels.

Sheila Patek, a researcher at Duke University, finds the discovery of gear wheels in young planthoppers to be wonderful. Patek is intrigued by the discovery in a specific stage of development and is not surprised if there are other creatures with similar structures.

It's important to note that while the insect's gear wheels are similar in shape to manufactured gears, the natural structures are asymmetrical. This suggests a unique evolutionary adaptation for the planthoppers.

Nature provides examples of gear-like structures on other animals, such as the cogwheel or spiny turtle (Heosemys spinosa), but those "gears" are ornamental, according to Burrows. The planthopper's gear wheels, however, serve a crucial function in their locomotion.

Burrows speculates that the inability of adults to replace lost gear teeth might be the reason for their abandonment of gear wheels. This raises interesting questions about the evolution of movement mechanisms in different stages of an animal's life cycle.

This discovery not only sheds light on the unique mechanics of planthoppers but also underscores the potential contributions that even the youngest researchers can make to science.