Arriving on the scene around 300 million years ago, dragonflies are one of the first insects to inhabit this planet. They've had a long time to perfect the art of flying, hunting and just being amazing. Here are seven facts that will change the way you look at these unique, ancient and incredibly varied insects.
Dragonflies can intercept prey mid-air
Dragonflies are flat out terrifying if you're a gnat, mosquito or other small bug. They don't simply chase down their prey. Instead, they snag them from the air with calculated aerial ambushes. Dragonflies can judge the speed and trajectory of a prey target and adjust their flight to intercept prey. They're so skilled that they have up to a 95 percent success rate when hunting.
The New York Times reports:
One research team has determined that the nervous system of a dragonfly displays an almost human capacity for selective attention, able to focus on a single prey as it flies amid a cloud of similarly fluttering insects, just as a guest at a party can attend to a friend's words while ignoring the background chatter. Other researchers have identified a kind of master circuit of 16 neurons that connect the dragonfly's brain to its flight motor center in the thorax. With the aid of that neuronal package, a dragonfly can track a moving target, calculate a trajectory to intercept that target and subtly adjust its path as needed ... As a rule, the hunted remains clueless until it's all over.
Basically, think "stealth fighter jet" when it comes to a dragonfly's ability to nab prey in flight quickly, effectively and intelligently.
Dragonflies have incredibly sharp mandibles
Their hunting strategy is impressive, but dragonflies' ability to rip apart prey takes their predatory prowess to another level.
Dragonflies and damselflies are in the order Odonata, meaning "toothed ones." The reason for the title is their serrated mandibles. When hunting, dragonflies catch prey with their feet, tear off the wings with their sharp jaws so it can't escape, and scarf the sorry bug down, all without needing to land.
Thankfully, dragonflies can't bite humans. The vast majority of species don't have mandibles strong enough to break the skin. Only a small handful of large species are capable of actually biting, but this only occurs as a defensive strategy. So there's no need to worry when you're walking around a dragonfly sanctuary (more on these below!).
Dragonflies are freaky fliers
There are few species in the animal kingdom that can match the dragonfly for spectacular flying ability. Dragonflies have two sets of wings with muscles in the thorax that can work each wing independently. This allows them to change the angle of each wing and practice superior agility in the air.
Dragonflies can fly in any direction, including sideways and backward, and can hover in a single spot for a minute or more. This amazing ability is one factor in their success as aerial ambush predators — they can move in on unsuspecting prey from any direction.
Not only are they agile, but they're fast, with some species reaching a top speed of 18 miles per hour. They're also up for feats of endurance. One species called the globe skimmer, Pantala flavescens, flies across an ocean during migration, logging 11,000 miles and snagging the title of world's longest insect migration.
Between the speed, distance and flexibility when hunting, dragonflies are one of the most exceptional fliers on the planet.
A dragonfly's head is all eyes
If you look at a dragonfly's head, you might notice one thing in particular. Or rather, 30,000 things in particular.
The area of an odonate's head is comprised primarily of its enormous compound eyes, which contain 30,000 facets, each bringing in information about the insect's surroundings. Dragonflies have near-360-degree vision, with just one blind spot directly behind them. This extraordinary vision is one reason why they're able to keep a watch on a single insect within a swarm and go after it while avoiding mid-air collisions with other insects in the swarm.
They not only have an exceptional field of vision, but they can see the world in colors we can't even imagine. According to New Scientist:
We humans have what's known as tri-chromatic vision, which means we see colors as a combination of red, blue and green. This is thanks to three different types of light-sensitive proteins in our eyes, called opsins. We are not alone: di-, tri- and tetra-chromatic vision is de rigueur in the animal world, from mammals to birds and insects. Enter the dragonfly. A study of 12 dragonfly species has found that each one has no fewer than 11, and some a whopping 30, different visual opsins.
Dragonflies live as long as 2 years underwater
Dragonflies lay their eggs in water, and when the larvae hatch, they live underwater for up to two years. Actually, depending on the altitude and latitude, some species may stay in the larval state for up to six years. They'll molt up to 17 times as they grow and get ready to head to the surface and transform into the dragonflies we see in the air.
They are specially adapted for the aquatic life in this stage, with the ability to snag prey at lightning speed. They'll eat a huge variety of food, including other insect larvae, tadpoles and even fish! And yes, they'll feast on other dragonfly larvae as well. These guys are predators to the max. You can learn more about the larvae stage in the video below:
Some dragonfly species lay eggs in saltwater
Entomologist Chris Goforth writes, "There are very, very few insects that live in the ocean. Several ideas have been proposed to explain why ... but one of the obvious reasons is that ocean water is salty and some insects might not be able to handle it. That doesn't seem to be a problem for some dragonflies though! Some species, such as the seaside dragonlet (Erythrodiplax berenicei) can successfully produce offspring in water many times saltier than the ocean."
Indeed, the seaside dragonlet is a stand-out species because its habitat consists of salt marshes, mangroves and saline lakes. It's the only dragonfly species in North America (but not in the world) with a range that's restricted to salty habitats.
You can visit dragonfly sanctuaries around the world
Dragonflies need of protection from the dangers humans have created, from pollution to habitat loss. Thankfully, there are sanctuaries around the world.
The United Kingdom got its first dragonfly sanctuary, The Dragonfly Center, in 2009. According to the Guardian, "Located at Wicken Fen nature reserve in Cambridgeshire, the new center hopes to reverse the decline of the 42 species found regularly in the U.K. Conservationists blame the decline on the loss of wetlands, and pesticides and insecticides drifting from farmland."
Dragonfly enthusiasts can visit a sanctuary in the southwestern United States. The Dragonfly Sanctuary Pond in Albuquerque, New Mexico, is the first sanctuary pond in the country and home to an amazing diversity of dragonfly and damselfly species.
Across the Pacific, enthusiasts can enjoy these odonates in one of several wildlife sanctuaries in Japan created to protect dragonfly habitats and the diversity of the species.
The dragonfly does an amazing job of helping humans by controlling the population of insects, especially those that bug us most, such as mosquitoes and biting flies. They also inspire us to create new technology based on their incredible skills at flight and vision. The least we humans can do to return the favor is support the conservation of their habitats so they can continue on for another 300 million years.