For a split second, Michael Wise wondered if his eyes were playing tricks on him.
“At first, I thought maybe I had been sitting in the lab by myself for too long,” he joked.
“I had not expected these little guys to be able to jump.”
Wise, a biologist and a professor at Roanoke College, had been in his campus lab methodically dissecting pieces of goldenrod and collecting the fly larvae that was burrowed within waiting to pupate and emerge, fully formed, into the world.
The larvae — teensy maggot-like organisms with an orange hue — were being set aside in the same petri dish.
Then Wise glanced down and realized the dish was nearly empty.
The little guys, without the benefit of leg or limb, had escaped.
Wise gave chase and found the larvae were leaping about the room. A few had nearly reached the wall — a distance many times greater than their diminutive body lengths.
The advent of jumping larvae isn’t unprecedented though neither is it common. Other specimens collected by Wise, who studies plant defenses against insects, showed little to no movement, let alone the ability to launch themselves across relatively wide gulfs.
The secret of how these legless, wingless creatures — a form of gall midge larvae — managed these aerial acrobatics had yet to be pinpointed.
Wise, who first noticed the phenomenon in 2012, shared the puzzle with a team at Duke University led by Sheila Patek, a former grad school classmate of Wise’s who specializes in breaking down the blink-and-you’ll-miss-it movements of the animal world.
Using a powerful high-speed camera, recording at the dizzying rate of 20,000 frames per second, Patek’s lab captured the details of the larval leaping and found it employed an intriguing spring-loaded approach.
A busy larva on the go will start by curling itself into a loop, touching head end to tail end, and latching those together using adhesive patches of microscopic hair-like structures.
The larva then starts churning its internal fluids, pushing them toward its lower end, creating pressure that builds until, snap, the latch springs open and sends it somersaulting through the air.
Specimens, no bigger than a grain of rice, were documented vaulting distances 36 times their body length.
Wise said anecdotally he’s spotted some covering even greater fields while in flight.
“They’re kind of among the champion jumpers,” he said. “And they’ll keep doing it until they run out of energy or dry up or find a good place.”
VIDEO: LEAPING LARVA IN MOTION
Credit: G. M. Farley, M. J. Wise, J. S. Harrison, G.P. Sutton, C. Kuo, and S.N. Patek, 2019, Journal of Experimental Biology
In August, the researchers published a paper in the Journal of Experimental Biology sharing their findings. The paper made a splash, something Wise hadn’t expected, and attracted national attention from a string of outlets including The New York Times, National Public Radio and The Atlantic.
“It’s nice to see something that you think is neat get interest from other people,” said Wise, adding he’s not accustomed to lay people wanting to hear him talk about his larval observations.
Wise said he wasn’t sure what it was about the spunky little leapers that struck a chord with people. “I don’t know if it was the gross factor or the cool factor,” he said. “Or maybe people were just in the mood to see something unexpected.”
The findings could hold significance for other arenas of research, including soft robotics, a field working to develop robots from pliable materials that are more resilient and adaptable than rigid components.
The squishy gall midge larvae, which are able to create these powerful, efficient motions, could help shape experiments in that work. Mechanical engineers are among those interested in the findings.
Wise, who co-authored the research paper, noted there also is more to explore from an ecological standpoint.
Still undetermined is exactly why these restless wanderers send themselves soaring through the air. Could it be a means of evading danger when rousted in their infancy or perhaps a vestigial trait evolved for purposes no longer known?
Wise said the carefully perfected nature of the jumping motion leads him to suspect that it meets some need.
“My sense is that this behavior is so well-honed, so specific and so effective that there must be some selective advantage to doing it,” he said.
“But that’s one of the big questions,” he added. “There’s more to do in terms of nailing down where these midges fit in evolutionarily.”