15 Awesome Facts About Dragonflies

Dragonflies are essentially harmless.

There are over 3,000 known dragonfly species living on nearly every continent in the world.

They're the oldest insect, have three main body segments and six legs, their vision and flight is unmatched, and they're pretty damn beautiful too!

Here we're going to explore 15 awesome facts about dragonflies that you probably didn't know!

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1. Damselflies are often confused with dragonflies.
The Odonata family of insects only has two main species, the dragonfly and damselfly.
The key to identifying them is in their wings. A dragonfly has four wings, while a damselfly only has two. When a dragonfly rests, they spread their wings out horizontally, whereas damselflies tuck their wings in against their bodies.
Another indicator is their eyes. All damselflies' eyes are separated, while most dragonflies' eyes are together.

2. Dragonflies are older than dinosaurs.
It sounds shocking, but dragonflies roamed the earth long before dinosaurs came to the scene. Scientists have placed their existence at 300 million years, more than 60 million years ahead of the dinosaurs.

3. Dragonflies can be found worldwide.
Different species of dragonflies can be found in almost every corner of the world.

4. Male dragonflies fight for territory.
Male dragonflies will protect an area from other male dragonflies of their species so that they will have the best chance at mating with as many females as possible.

5. Male dragonflies have multiple sex organs.
Their copulatory organs are on the underside of the abdomen, up around the second and third segments. Dragonfly sperm, however, is stored in an opening of the ninth abdominal segment. Before mating, the dragonfly has to fold his abdomen in order to transfer his sperm to his penis.

6. Dragonfly nymphs live underwater.
Female dragonflies deposit their eggs on the water's surface, or in some cases, insert them into aquatic plants or moss. Once hatched, the nymph dragonfly spends its time hunting other aquatic invertebrates. Larger species even dine on the occasional small fish or tadpole. After molting somewhere between six and 15 times, a dragonfly nymph is finally ready for adulthood and crawls out of the water to shed its final immature skin.

7. Nymphs breath through their anus.
The damselfly nymph actually breathes through gills inside its rectum. Likewise, the dragonfly nymph pulls water into its anus to facilitate gas exchange. When the nymph expels water, it propels itself forward, providing the added benefit of locomotion to its breathing.

8. Dragonflies are incredibly skilled in flight.
Dragonflies are able to move each of their four wings independently. They can flap each wing up and down, and rotate their wings forward and back on an axis. Dragonflies can move straight up or down, fly backward, stop and hover, and make hairpin turns—at full speed or in slow motion. A dragonfly can fly forward at a speed of 100 body lengths per second (up to 30 miles per hour).

9. Dragonflies are some of the most efficient hunters in the world!
Adult dragonflies are predators, living off an almost exclusively carnivorous diet based on other insects such as mosquitoes, flies, moths, as well as smaller dragonflies.
While hunting prey, dragonflies have a catch rate of 95%, higher than any other animal observed. The secret to their success lies in the many unique adaptations they have accumulated throughout their evolution, including aspects of their eyesight and flight.

10. Dragonflies are calculated killers.
In other words, dragonflies ensure a kill by flying to where their prey is going to be.
That indicates that dragonflies calculate three things during a hunt: the distance of their prey, the direction it's moving, and the speed it's flying.

11. Dragonfly eyes are a sight to behold.
Relative to other insects, dragonflies have extraordinarily keen vision that helps them detect the movement of other flying critters and avoid in-flight collisions. Thanks to two huge compound eyes, the dragonfly has nearly 360° vision and can see a wider spectrum of colors than humans. Each compound eye contains 28,000 lenses or ommatidia and a dragonfly uses about 80% of its brain to process all of the visual information it receives.

12. Some species of dragonflies migrate further than you'd think!
A number of dragonfly species are known to migrate, either singly or en masse. As with other migratory species, dragonflies relocate to follow or find needed resources or in response to environmental changes such as impending cold weather.
Green darners, for example, fly south each fall in sizeable swarms and then migrate north again in the spring. Forced to follow the rains that replenish their breeding sites, the globe skimmer—one of several species that's known to spawn in temporary freshwater pools—set a new insect world record when a biologist documented its 11,000 mile (17,702 km) trip between India and Africa.

13. Dragonflies can regulate their body temperature.
Dragonflies, like all insects are cold-blooded, or ectothermic, the preferred term these days. In short, they are not able to regulate their internal body temperature in the same way that mammals and birds do, and depend in large part on sunlight and ambient air temperature.
They're able to warm themselves up by a process called wing-whirring, where they vibrate their wings at such a speed that it generates heat!
Conversely, during hot spells, some dragonflies strategically position themselves to minimize sun exposure, using their wings to deflect sunlight.

14. Dragonflies have long been considered evil in Western culture.
Swedish folk legends accused dragonflies of poking out people's eyes and referred to them as "blind stingers" for this reason. From Germany to England, people associate dragonflies with the devil, giving them nicknames like "water witch," "hobgoblin fly," "devil's horse," and even "snake killer."

15. Dragonflies aren't considered to be sinister everywhere, though.
In Japanese culture, dragonflies hold a special significance and are often seen as symbols of courage, strength, and happiness.


Sources
Britannica / MNN / Smithsonian Mag / Wikipedia / ThoughtCo
Image credit: unknown