46 Fun Facts About Dragonfly

Dragonflies and damselflies make up which insect order?

Odonata: the name, from the Greek for tooth, is thought to point to the insects' serrated jaws. Diptera are the true flies, Mantodea the mantises and Ephemeroptera the mayflies.

Roughly how many species of dragonfly exist?

About 3,000 dragonfly species are known. A first global assessment in 2021 found roughly one in six dragonfly and damselfly species at risk of extinction.

A dragonfly's compound eye has over 20,000 facets, each with its own what?

Lens: each facet is a separate light-gathering unit called an ommatidium, and together they give a dragonfly a field of vision approaching 360 degrees.

At rest, how does a dragonfly hold its wings, unlike a damselfly?

Flat and out from the body. Dragonflies lack the hinge that lets most insects fold their wings back over the abdomen, an ancient limit they share with mayflies.

NASA's rotorcraft mission named Dragonfly was designed to fly across which moon of Saturn?

Titan has air about four times denser than Earth's and roughly a seventh of its gravity, which makes flying the easiest way to move a lander between sites there.

Roughly how long does a typical adult dragonfly live once it takes to the air?

A few weeks, though large species can manage some months. That is the short final act of a life spent mostly underwater, where the nymph can take years to grow.

In which dragonfly mating posture does the male grip the female's head while the female curls her abdomen forward?

The heart or wheel, a posture unique to dragonflies and damselflies. It is needed because the male moves his sperm beforehand to a second set of organs near the base of his abdomen.

Giant 'griffenflies', with wingspans up to 75 cm, first appeared in which geological period?

Carboniferous, about 325 million years ago. Though often called giant dragonflies, griffenflies belonged to an extinct order of their own and were not true dragonflies.

What do adult dragonflies mainly eat?

Other flying insects, mostly midges and mosquitoes seized in mid-air. The bigger species also take butterflies, moths and even smaller dragonflies.

One hypothesis for Meganeura's giant size links it to high levels of what in the ancient atmosphere?

Oxygen: richer ancient air was long thought to let an insect's breathing tubes supply a bigger body. The idea is now disputed, partly because giant griffenflies lived on after oxygen levels fell.

Where are the gills of a dragonfly nymph found?

Inside its rectum: the nymph draws water in and out of its abdomen to breathe. Damselfly nymphs instead wear their gills outside, as leaf-like plates at the tip of the tail.

Which is the only continent with no dragonflies?

Antarctica alone has none. Dragonflies are such strong fliers that they have colonised remote ocean islands, and a single species occurs on every other continent.

Which dragonfly is considered the world's most widespread, turning up in warm regions on almost every continent?

The globe skimmer, Pantala flavescens, breeds in short-lived rainwater pools, so it follows the rains across continents and even over open sea.

Millions of dragonflies ride monsoon winds on a yearly circuit of up to 18,000 km across which ocean?

Indian: successive generations relay from India to East Africa and back, and single insects cover more than 6,000 km of the route.

Dragonfly legs are built for perching and seizing prey, which leaves the insect barely capable of what?

Walking is almost beyond a dragonfly. In flight its spiny legs point forward to form a basket that scoops prey out of the air.

A dragonfly nymph catches prey by shooting out which body part, sometimes called a mask?

Its lower lip, the labium, shoots out at speed, seizes the victim and drags it back to the jaws; tadpoles and even small fish are caught this way.

How can a dragonfly nymph move with sudden speed through a pond?

Jet propulsion from its rear end: the nymph breathes by pumping water through its abdomen, and squirting that water out hard shoots it forward to escape danger.

A newly emerged dragonfly, called a teneral, is easy prey mainly because its wings are still what?

Soft: a teneral is pale and flies weakly until its body and wings harden, so many are picked off by birds on that first flight.

Unlike butterflies, dragonflies skip which stage of life entirely?

The pupa: a full-grown nymph simply climbs out of the water, its skin splits and the winged adult hauls itself free, leaving the empty case behind.

Roughly how fast can a large dragonfly such as a hawker fly?

50 km/h in a sprint, yet the same insect can hover on the spot and even fly backwards.

While a fly flaps by flexing its thorax, what drives a dragonfly's wings?

Muscles attached straight to them: a tug on the wing base just inside its hinge levers the wing up like an oar, and a second set just outside the hinge pulls it down.

In one study, what spoiled more dragonfly attacks on fruit flies than deliberate dodging did?

Random turns: the flies rarely tried to dodge and rarely escaped when they did, but their routine, erratic swerves made more attacks fail than any evasive move.

Which trick do male dragonflies use to sneak up on a rival in mid-air?

Motion camouflage: the attacker keeps itself on a line between its rival and a fixed point, so it looms larger without seeming to move. Stereo cameras caught males doing it in territorial dogfights.

What do cold dragonflies do to heat their flight muscles when there is no sun to bask in?

Wing-whirring: the insect shivers its wings rapidly without taking off, and the working flight muscles heat up. They must be warm to fire properly, which is why dragonflies also bask.

Dragonflies sometimes lay eggs on cars, gravestones and solar panels because these surfaces mimic water how?

They reflect polarised light, just as a pond does: egg-laying dragonflies find water by the horizontally polarised glare off its surface, so dark glossy paint, stone and glass fool them.

Clubtail dragonflies mostly breed in which kind of water?

Flowing rivers and streams: clubtail nymphs need clean riverbeds, so water pollution hits them hard.

Which large migratory dragonfly is the official state insect of Washington?

The common green darner, Anax junius, became Washington's state insect in 1997. Researchers have fitted these migrants with tiny radio transmitters and followed them south in autumn.

One of Britain's largest dragonflies, a hawker with a blue abdomen, is named after which ruler?

The emperor, Anax imperator, is Britain's bulkiest dragonfly and rarely lands, even eating its catch on the wing; since the 1990s it has spread north as far as Scotland.

The helicopter damselflies of tropical America, with wingspans up to 19 cm, feed mainly on what?

Spiders plucked from webs: the giant hovers before an orb web and snatches its builder. Its own young grow up in rain-filled tree holes, so the species depends on old forest.

In the American South, dragonflies were nicknamed 'snake doctors' from a belief that they did what?

Tended sick or injured snakes: Southern folklore had dragonflies following snakes around, nursing the sick back to health in one telling and stitching up the injured in another.

For the Navajo, the dragonfly is a symbol of what?

For the Navajo the dragonfly stands for pure water, and its image is drawn into sacred sandpaintings to represent that element.

In which country are adult dragonflies caught on birdlime-coated poles and fried in oil as a delicacy?

In Indonesia, adult dragonflies are caught on poles tipped with sticky birdlime and fried in oil as a delicacy; in China and Japan they have traditionally been used in medicine instead.

Many sinister old folk names for dragonflies grew from which popular misconception?

That they bite or sting humans: a big dragonfly held in the hand may try to nip but cannot break the skin, and its egg-laying tube is no stinger. 'Devil's darning needle' added a myth of sewn-up eyes.

Which art movement made the dragonfly a favourite motif, especially in jewellery?

Art Nouveau jewellers loved insects: René Lalique's dragonfly-woman corsage ornament, its hinged wings set with enamel and diamonds, was a triumph at the 1900 Paris Exposition.

Which Victorian poet clad a newly hatched dragonfly in 'plates of sapphire mail' in The Two Voices (1842)?

Lord Tennyson has the insect tear open 'his old husk', dry wings that grow 'like gauze' and fly off as 'a living flash of light'.

What did Japanese children sling skyward to catch large dragonflies?

A hair with a pebble on each end: children in Kii province slung this tiny bolas high, a dragonfly pounced on it as prey, the hair wrapped round its body and the weight brought it down.

A 2021 global Red List assessment blamed the worldwide decline of dragonflies mainly on what?

Wetland loss: wetlands such as the marshes and swamps where the nymphs grow up are vanishing about three times faster than forests.

Why do some perched dragonflies point the abdomen straight at a hot midday sun?

To catch less heat: in this handstand, known as the obelisk posture, only the tip of the abdomen faces the sun, so the least possible body surface meets its rays.

Some dragonflies do not drop their eggs into open water; where do these females put them instead?

Inside plant stems: a hawker settles and slits each egg into a stem or leaf with a blade-like egg-laying tube, while darters dip the abdomen and drop theirs loose into the water.

What is the tadpole-like first stage of a dragonfly, which moults within hours of hatching, called?

The prolarva is a tiny, barely active hatchling that soon moults into the true nymph; one that hatches above the waterline first has to wriggle down to safety.

What colour are dragonfly nymphs usually?

Dull brown, green and grey: the drab mix hides a nymph among pond weed and mud, which suits a hunter that ambushes its prey. The bright colours arrive only with the adult.

Which small birds of prey are fast enough to catch adult dragonflies on the wing?

Kestrels, merlins and hobbies are small, agile falcons. A hobby runs a dragonfly down at speed, passes it from talons to beak in mid-air and eats it without landing.

The pterostigma, a dark thickened cell near each dragonfly wingtip, helps flight by acting as a tiny what?

Weight: the cell is heavier than the wing around it, and that speck of mass governs how the wingtip twists on every stroke, which makes the dragonfly's flight more efficient.

What have female moorland hawker dragonflies been seen doing to shake off unwanted males?

Crash-diving and playing dead: a chased female drops out of the air and lies still on the ground until the male loses interest, which spares her a forced mating.

Which parasites use dragonfly nymphs as a stepping stone between pond snails and the frogs whose lungs they infect?

Flukes: their swimming larvae leave a snail, get into a dragonfly nymph and wait there as cysts. A frog that eats the infected dragonfly swallows the flukes, which then settle in its lungs.

In the cyborg 'DragonflEye' project, how are steering commands delivered to the insect's nerve cord?

By light through flexible optrodes: its steering neurons are genetically altered to respond to light, which hits only those cells, so a solar-powered backpack can steer while the insect does the flying.