May 16, 2022 | David F. Coppedge

Dragonfly Cat Trick Explained

An upside down dragonfly can right itself 
faster than the blink of an eye.

 

As every cat-tormenting junior knows, Tabby can flip over quickly and land on her feet if dropped upside down, hopefully over a soft couch. If cats had wings, they might be able to do it much faster. Scientists at Cornell University figured out how dragonflies do it, but the scientists had to use sophisticated imaging equipment and computer models.

Dragonflies use vision, subtle wing control to straighten up and fly right (Cornell Chronicle, 13 May 2022). Years ago, Jane Wang at Cornell became intrigued at the righting behavior of dragonflies. Knowing that dropped airplanes can’t do this, she figured there had to be a mechanism, but it happened so fast she couldn’t see how the living flyers accomplished the feat.

With their stretched bodies, immense wingspan and iridescent coloring, dragonflies are a unique sight. But their originality doesn’t end with their looks: As one of the oldest insect species on the planet, they are an early innovator of aerial flight.

Now, a group led by Jane Wang, professor of physics in the College of Arts and Sciences and professor of mechanical and aerospace engineering in the College of Engineering, has untangled the intricate physics and neural controls that enable dragonflies to right themselves while they’re falling.

A dragonfly eye can have up to 30,000 facets. The head also has an organ for measuring optical flow called the ocellus.

The dragonfly’s cat trick involves not only its wings, but its five eyes, muscles and brain. Five eyes? Yes; dragonflies have a central vision organism called an ocellus. The dragonfly’s three ocelli send “optic flow” information to the brain—that is, a stream of data on pitch, yaw and roll that flows past the head on all sides. Optic flow tells the insect whether it is turning, diving or locking onto a target.

Scientists already knew that dragonflies had this sophisticated flight equipment (see 25 August 2021), but only now did the Cornell team figure out how they perform the cat trick—a feat that is “difficult to engineer.” The research was hard work, Wang says.

“When we looked at their flight behavior, we were simultaneously in awe and frustrated,” she said. “The trajectories are complex and unpredictable. Dragonflies constantly make maneuvers, without following any obvious direction. It’s mysterious.”

First, her team determined that the eyes have it. Blinded, the dragonflies could not right themselves. The secret was revealed with kinematic analysis, high-speed photography, followed by computer models and flight simulations. With working vision, dragonflies do the cat trick rapidly, in about 2 eye blinks.

Amazing FactsThat visual cue triggers a series of reflexes that sends neural signals to the dragonfly’s four wings, which are driven by a set of direct muscles that modulate the left-wing and right-wing pitch asymmetry accordingly. With three or four wing strokes, a tumbling dragonfly can roll 180 degrees and resume flying right-side up. The entire process takes about 200 milliseconds.

The coverage on Phys.org includes a short video clip of the action at 4,000 frames per second. Even so, it is hard to see how the four wings cooperate to pull it off. Wang and her two colleagues from Howard Hughes Medical Institute think that the cat trick is common to other flying insects, too.

Praise Evolution, Darwin Did It Again!

What brought about this exquisite flight engineering? How did nature endow this slender, awe-inspiring insect with the cat trick? We already know what they’re going to say. It’s just sad to keep reading it day after day, with no critical thinking, debate or logic.

“Insects are the most abundant species and were the first to discover aerial flight. And dragonflies are some of the most ancient insects,” Wang said. “Trying to look at how they right themselves in air would give us insight about both the origin of flight and how animals evolved neuro-circuitries for balancing in air and navigating through space.”

Maybe one of the other science news outlets will submit this explanation to critical analysis. Let’s check in with a couple of reporters:

How dragonflies use ultrafast wing movements to flip over in flight (Corryn Wetzel at New Scientist, 12 May 2022).

“I think almost all flying insects have such an ability, because it’s a necessity,” she says. “Dragonflies are one of the most ancient insects. If they have already evolved it, I suspect the modern ones have a similar ability.

How do dragonflies right themselves in mid-air? (Andrei Ionescu at Earth.com, 13 May 2022).

Dragonflies, one of the most ancient insect species, are highly skilled flyers, exhibiting a repertoire of complicated flight maneuvers. For instance, they have evolved sophisticated reflexes that enable them to right themselves when falling or after being flipped upside-down during flight.

The diligent reporter quotes Jane Wang without asking any hard questions:

“Insects have evolved sophisticated reflexes to right themselves in mid-air. Their recovery mechanisms involve complex interactions among the physical senses, muscles, body, and wings, and they must obey the laws of flight. We sought to understand the key mechanisms involved in dragonfly righting reflexes and to develop physics-based models for understanding the control strategies of flight maneuvers,” explained the study authors.

Dragonflies righting the world with impressive aerial dynamics (Qamariya Nasrullah in Cosmos: The Science of Everything, 14 May 22022).

Dragonflies are one of the most ancient groups of insects, originating some 325 million years ago, and are known to be highly skilled flyers. Not only are they long-distance champions, but they perform a repertoire of complex flight manoeuvres.

Nasrullah does not mention evolution, but she implies it with the statement that insects were “originating” 325 million Darwin Years ago.

Is necessity the mother of innovation in Darwin Fantasyland? Did insects get their flight hardware and software because it was “a necessity” as Wang believes? Does Darwin have a delivery service? If so, then I need wings. Do I order them on Darwazon.com? Funny that stick insects got by without this ‘necessity.’

We hope you enjoyed our funny joke—the suggestion that a science news site would apply critical thinking to evolutionary claims. That was a groaner, indeed! Instead, evidence appears to indicate that common sense only evolved in creationists. (Another joke.)

A dragonfly’s four wings make 30 beats per second or 1,800 beats per minute. (Credit: Illustra Media, “Ode to the Animals”).

 

 

 

 

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