“Dragonflies are prehistoric insects, having flown on Earth since before the dinosaurs!”
Emperor dragonflies patrol ponds, lakes, and slow waterways across Europe and western Asia. Adults intercept insects in flight with independently controlled wings, while aquatic nymphs spend their earlier lives hunting below the surface.
By An Nguyen · Published · Updated
Measured against the 176 species profiled on this site. Each figure is converted to one unit system from the published range on the page, so the ranks are computed, not quoted.
| Measure | This species | Rank here | Exceeds |
|---|---|---|---|
| Body mass | 2 g | #170 of 176#5 of 11 Insecta | 3% |
| Body length | 8 cm | #167 of 176#5 of 11 Insecta | 5% |
| Top speed | 48.3 km/h | #37 of 75 | 46% |
| Lifespan in the wild | 0.17 yr | #168 of 169#10 of 11 Insecta | 1% |
Closest in body mass
Ranks use the upper end of each published adult range, so they compare typical large adults rather than records, and metrics with no published number are left out rather than estimated. The full table is downloadable from the species dataset, and any two species can be put side by side in the comparison tool.
Browse photographs of dragonfly across habitat, behavior, anatomy, and life stages.
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Core article
A closer look at habitat, diet, behavior, reproduction, and conservation.
The Emperor dragonfly (Anax imperator) is a large, iridescent predatory insect whose order predates the first dinosaurs. It is an agile flier, able to hover, fly backward, and make sharp turns at speeds up to 30 mph. Its large compound eyes provide a nearly 360-degree field of vision. As a predator, it consumes large numbers of mosquitoes, midges, and flies in freshwater wetlands.
Scientifically classified as Anax imperator, the Emperor dragonfly belongs to the kingdom Animalia, phylum Arthropoda, and the class Insecta. It is a prominent member of the order Odonata, which encompasses all dragonflies and damselflies, and falls within the family Aeshnidae, known as the "hawkers" or "darners."
The order Odonata has a fossil history extending more than 300 million years. Large Carboniferous relatives such as Meganeura had wingspans exceeding two feet, although they were not members of a modern dragonfly family. Modern dragonflies are much smaller and usually hold their wings open at rest because they lack the folding mechanism used by many other winged insects.
An adult Emperor dragonfly measures about 7 to 8 cm long and weighs roughly 1 to 2 grams. Its long abdomen, blue in mature males and green in females, helps stabilize the insect during turns and acceleration.
Two large compound eyes dominate the head, each containing up to about 30,000 ommatidia. Their broad field of view leaves only a small blind area and helps the dragonfly track moving prey in flight.
Dragonflies have two pairs of transparent, heavily veined wings controlled by thoracic muscles. Varying the timing and angle of the forewings and hindwings allows rapid acceleration, hovering, backward flight, and abrupt turns. The legs sit far forward and carry stiff bristles that form a basket around airborne prey; they are less suited to prolonged walking.
Anax imperator is widely distributed across Europe, parts of Asia, and Africa, with records from the United Kingdom, France, Germany, South Africa, and other countries across its range.
Emperor dragonflies breed around slow-moving rivers, large ponds, marshes, and other freshwater wetlands. Because most of the life cycle is spent underwater as a nymph, successful development depends on suitable water quality and aquatic vegetation such as reeds and submerged plants.
Dragonflies are obligate carnivores that eat other flying insects, including mosquitoes, flies, gnats, moths, butterflies, and smaller dragonflies. Their predation can reduce local numbers of some insect prey, although it does not by itself control every pest population.
The praying mantis is another insect predator, but it usually waits on vegetation rather than intercepting prey over open water.
Dragonflies often intercept prey rather than following directly behind it. Visual tracking helps the insect steer toward a predicted meeting point, where the bristled legs close around the target. Reported capture rates can be high in controlled observations, but they vary by species, prey, and conditions. The dragonfly may consume small prey in flight using serrated mandibles.
Adult dragonflies are generally solitary. Male Emperor dragonflies patrol sections of water used for breeding and chase other males from those areas.
They establish territories around breeding sites, usually sections of a pond with abundant aquatic vegetation. A resident male may chase an intruding male through rapid turns and short aerial contact until one leaves the area. Adults are generally solitary outside mating, spending much of their time hunting and defending access to breeding habitat.
Dragonflies undergo incomplete metamorphosis, developing from egg to aquatic nymph and then to winged adult without a pupal stage. After mating, a female Emperor dragonfly uses her ovipositor to place eggs in submerged plant tissue.
After incubation, the eggs hatch into aquatic nymphs (naiads). A nymph uses an extendable lower jaw to catch mosquito larvae, tadpoles, and small fish. Depending on species and water temperature, this stage can last from several months to several years. At maturity the nymph climbs emergent vegetation, its exoskeleton splits, and the winged adult emerges. The adult stage commonly lasts weeks to a few months.
(Population and conservation trend data sourced from the IUCN Red List of Threatened Species)
The Emperor dragonfly is assessed by the IUCN as Least Concern, supported by its broad geographic range and use of artificial water bodies such as garden ponds and reservoirs.
Dragonfly communities can help indicate the condition of wetland ecosystems. Agricultural runoff, pesticides, and wetland drainage can reduce suitable freshwater habitat. Because nymphs develop underwater, sustained pollution or oxygen loss can prevent a local generation from reaching adulthood.
Kingdom
Animalia
Phylum
Arthropoda
Class
Order
Odonata
Family
Aeshnidae
Genus
Anax
Species
A. imperator
Dragonflies are prehistoric insects, having flown on Earth since before the dinosaurs!
They can hover, fly backward, and briefly fly upside down.
A dragonfly has nearly 360-degree vision, with two giant compound eyes containing up to 30,000 lenses each.
They are expert hunters, catching up to 95% of the prey they target in mid-air.
Baby dragonflies, called nymphs, live underwater for up to 5 years before emerging as flying adults.
Dragonflies can move each of their four wings independently, allowing them to make sharp turns in a split second.
Select a question to reveal the answer.
Dragonflies live near freshwater habitats such as ponds, lakes, marshes, and slow-moving streams where they can find plenty of insects to eat.
They are carnivores that eat other flying insects, including mosquitoes, flies, gnats, butterflies, and moths. They catch their food in the air using their legs.
Dragonflies have two pairs of wings that can move independently, letting them hover, turn sharply, and fly backward.
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