Dragonflies: First In Flight

I’ve been hooked on YouTube videos about biology these days. It’s an excellent format: about 20 minutes is all you need to digest a topic. The content is often well-produced, it’s free, and personal. I don’t know why I started getting curious about Dragonflies, but I loved this one by PBS Terra.

 

Dragonflies, or at least their predecessors, were the first creatures that actually flew. That was only about 400 million years ago, not long in the lifespan of Earth. Until then, we were mostly a soup of microbes and viruses. That’s also fascinating, but how did we get to flight after being on land for so long?

Image credit: Dragonfly ran-384 by R. A. Nonenmacher, licensed under CC BY-SA 3.0.

The Evolution and Advantages of Flight

We don’t really know, but there are many hypotheses, like so many evolutionary advantages in nature, that flight emerged slowly. One popular hypothesis, called the plural origin hypothesis or the gill or exite hypothesis, states that wings and flight likely evolved from leg-gill structures (exites) that fused with the body wall, giving insects movable, jointed wings. 

 

At first, the wings could have simply been used to glide from place to place, perhaps for temperature regulation, or for use as camouflage or a protective shield, or for something else entirely. 

 

But eventually, these turned into flight. Despite it being a beta version for animal flight, it is still one of the most advanced flight designs around. 

Unique in the Insect World: Independent Wings

By far the majority of insects have modified or reduced one pair of wings or even mechanically coupled their fore and hind wings. 

 

As you have probably noticed, dragonflies are unique in the insect world for having two pairs of wings (forewings and hindwings) that, unlike most insects, can be moved independently, thanks to their direct flight muscles attached to the base of each wing that most insects do not possess. Only dragonflies and damselflies have maintained their four-winged independent control for over 350 million years of evolution. 

 

But what does that mean for the dragonflies? Previous studies showed that dragonflies’ independent wings result in a significant reduction in lift, suggesting a hindrance rather than a benefit. However, the benefits are substantial in terms of improving aerodynamic efficiency. Dragonflies achieve this by reducing up to 22% energy wasted from the wake as swirl compared with a single pair of wings, in a manner not unlike the coaxial contra-rotating helicopter rotors, which are now being investigated in the future development of biomimetic micro air vehicles.

 

This enables dragonflies to be highly successful aerial predators, boasting remarkable agility and endurance in flight. This gives them the speed of a plane with the control of a helicopter, allowing them to hover, assess, and scoop. They can fly at low speeds or exceed 30 miles per hour, but also stop on a dime, hover, move backward, and even fly upside down. They are true masters of the sky.

95% Predator Kill Rate

But dragonflies aren’t just amazing in flight. Their prey: mosquitoes, horseflies, and even wasps don’t stand a chance. With their exceptional vision, compound eyes with a nearly 360-degree view, predictive hunting, aerial acrobatics, motion camouflage (making them appear stationary in flight), and ability to capture prey in mid-flight, scooping them with their six legs without having to stop, they can snatch up prey with an amazing 95% success rate, virtually unheard of in the natural world. 

 

As a sci-fi nerdy kid, I understood just how bad-ass they were. With their giant eyes and exceptional acrobatic skills, they just looked so cool! They’d appear on the scene, buzz around, and then take off. We even see the dragonfly flight design in popular culture, such as the ornithopter in Dune.

Ornithopter ship in Dune

Flying Sperm Scoopers?!

I’d sometimes see two dragonflies having sex while flying, and I thought to myself, How can they do that? It was comical, and as kids, seeing animals reproduce was funny, curious, and deconstructed sex as a hidden or shameful act.

 

Dragonflies often mate in flight, where the male will grasp the female’s neck with specialized claspers and form a tandem linkage where the female folds her abdomen forward to meet the male’s reproductive organ, should she choose to accept him and his genetic offerings. 

 

Why mate in flight? It shows off their acrobatic abilities, demonstrating their flight skills and making them more appealing as a genetic partner. Some males will even continue to fly with the female afterwards, known as ”contact guarding,” to prevent other males from approaching. 

 

Still, some dragonflies have yet another trick up their sleeve, er, abdomen. When mating, before passing his own sperm, the male uses specialized penile structures, backward-facing hooks or barbs on their penises, to scoop out or displace sperm from rivals, so that they have the best chance of fertilizing the eggs. 

 

Flying sperm scoopers? Badass indeed.

Why Dragflies Endure The Test of Time

Dragonflies have been buzzing around for hundreds of millions of years, but they still feel futuristic to me. Watching them hover, dart, and outmaneuver anything is like seeing a perfect blend of fighter jet and sci-fi spaceship. Maybe that’s why they’ve always caught my imagination, from childhood curiosity to late-night YouTube rabbit holes. They aren’t just prehistoric relics of a distant past; they’re living proof that some designs are perfect enough that they just don’t need updating.