High-speed cameras show maggots forming "transient legs" to leap into the air
Jumping probably isn't an ability that most people would associate with tiny creepy crawlies like maggots, but some, such as the larva of the goldenrod gall midge, can actually leap distances far greater than their microscopic bodies might suggest. By turning advanced cameras to these legless larvae in action, scientists have gained a new understanding of their relatively high-flying antics, including an ability to form what they call a "transient leg."
Modern-day cameras that can capture video at extremely high frame rates are allowing scientists to observe natural phenomena in new and very useful ways. We have seen scientists use this kind of gear to study viper strikes, lightning storms and human sneezes, to list just a few examples.
By using them to investigate the acrobatics of the larva of the goldenrod gall midge, scientists at Duke University hoped to shed new light on a mystery that dates back decades. Legless larvae have actually been know to possess jumping abilities for more than 50 years, the scientists say, but how they actually get themselves off the ground hasn't been so well understood.
High-speed camera technology combined with scanning electron microscopes has now enabled them to unravel some of the secrets. The team's camera captured footage at 20,000 frames per second and was used to film the leaping larvae over "countless hours" of activity. Throughout, the tiny worms often leapt right out of the frame and covered distances up to 30 times their own body length.
The footage revealed that they achieve this by curling their body up to attach their head to their tail and form a ring shape, with two sticky patches of skin forming a bond. This maneuver causes internal fluids to gather and build up pressure in the tail section up until the point that the bond breaks. At this point, a hinge mechanism about a third of the way up its body acts as a transient leg, delivering power to the floor as it is released to propel the worm through the air.
The electron microscope imagery revealed the sticky sections of skin to be rows of finger-like scales, similar in appearance to the sticky surfaces on gecko feet. These might adhere to one another by interlocking, while a weak electromagnetic attraction, like that seen in geckos, is another possibility.
As for why these worms choose to launch themselves into the air rather than simply crawl across a surface, the scientists say this method of transport is around 28 times more energy efficient. It also happens to be a whole lot faster, which could be useful for escaping predators, for example.
The research not only furthers our understanding of legless larvae and similar maneuvers performed by other insects, it could provide guidance in the field of soft robotics, where scientists are constantly turning to the natural world for inspiration.
The research was published in the Journal of Experimental Biology.
Source: Duke University