As nymphs, the dragonfly molts several times under the water. Molting is a process in which an insect sheds its exoskeleton to make room for new growth.
The nymph eventually makes its way to the surface, where it stays and waits for its respiratory system to adjust to the air. Then the dragonfly finds a place to molt, and completes the process into adulthood.
After the dragonfly becomes an adult, it usually only lives for a few months , during which time it reproduces with other dragonflies. Most individuals are caught and eaten by predators. Dragonfly behavior remains mysterious in lots of ways, but there are some notable dragonfly behaviors. They usually stay nearby, defending their territory from other dragonflies or sometimes, other insects. Males in particular are known to be highly territorial , and even more so during breeding season, when females have to mate with them in order to lay eggs in their territory.
Dragonflies are strong and agile flyers. They are capable of flying over large bodies of water. They use a number of different flying techniques, which helps them hunt and cover a lot of ground when looking for mates. They can fly at speeds up to 34mph , though their cruising speed is around 10mph. Dragonflies are also known to hover. Dragonflies are actually carnivorous. They have strong jaws with sharp teeth that they use for catching and eating, and primarily eat other bugs. Their diet consists of smaller bugs like mosquitos, moths, and butterflies.
Dragonflies use their flying skills and excellent eyesight to pursue their prey. When catching larger prey, the dragonfly will subdue it by biting its head and dragging it back to its perch. Nymphs are also aggressive hunters, eating most of the small living things they encounter underwater. The green darner is a North America dragonfly species that migrates each year. However, they migrate individually, not in groups like birds. Dragonflies are a key controller of mosquito populations.
They can eat up to a hundred mosquitoes per day. Some species occasionally meet in swarms. Scientists are unsure about what causes this behavior, but think it has something to do with hunting or mating. Dragonflies are considered near perfect flyers, and they have been studied by scientists to see if replicating their structure is possible. Dragonflies have been around for about million years.
Ancient dragonfly fossils show specimens with wingspans of up to two feet. In Britain, lucky Damsel adults seldom manage more than two weeks and Dragons more than two months. Most Damsels rarely go more than a week, and Dragons two or three weeks. They die from accidents and predation, and large numbers from starvation — in poor weather neither they nor their prey can fly.
No insect has a lifespan of only one day — even mayflies not closely related to dragonflies live for several months underwater as larvae before emerging as winged adults. In the UK dragonflies reach a length of about 85 mm and a wingspan of about mm. Damselflies, which are the much smaller and weaker flying relatives of dragonflies, are much smaller.
The largest in the UK are the Demoiselles. These have a body length of about 50 mm and a wingspan of about 60 mm.
The biggest wingspan of a living dragonfly is the Central American Megaloprepus coerulatus with a wingspan about 19 cm. This is a thin, long-abdomened damselfly.
The bulkiest dragonfly may be Petalura ingentissima from Australia female wingspan to about 16 cm , a central African Anax species or a reported, but apparently uncollected, aeshnid from Borneo. This species is only 15 mm long with a wing span of about 20 mm. In prehistoric times dragonflies were much larger, the largest flying insects ever.
The largest member of the extinct Protodonata was the Permian Meganeuropsis permiana with a reconstructed wingspan based on fragments, scaled to complete fossils of similar animals of about cm. All the links in this answer take you to photos, displayed in a new browser window, outside the BDS web site. Average cruising speed is probably about 10 mph. Small species, and especially damselflies, are generally slower, although many medium-sized species can probably keep up with the largest ones.
When dragonflies and damselflies first emerge from their water-borne larval stage, most have very muted colours. Depending on weather conditions, it can take a few days for them to gain their bright adult colour. Common Blue damselflies are often a pale pinkish-brown rather than sky-blue on first emergence. Some damselflies undergo a gradual colour change as they age, for example the Blue-tailed Damselfly.
The females have several different colour forms and some change from violet to rich brown while others go from salmon-pink to blue. Some of the larger dragonflies also change colour as they age. Older females may start to develop the colouration of the males.
Examples are Common Darter , which goes from yellow-brown to reddish brown, and Black-tailed Skimmer , which goes from yellow-brown to a blueish-grey. Greatly simplified, the life cycle is Egg usually laid under water , Larva free moving, water dwelling nymph and Adult. The larva lives for several weeks or years depending on species underwater and undergoes a series of moults as it grows. Mainly, adult dragonflies eat other flying insects, particularly midges and mosquitoes.
They also will take butterflies, moths and smaller dragonflies. There is one Asian species which takes spiders from their webs! The larvae, which live in water, eat almost anything living that is smaller than themselves.
The larger dragonfly larvae are known to catch and eat small fish or fry. Usually they eat bloodworms or other aquatic insect larvae. Dragonflies certainly do eat large numbers of flying pest species, but using them to control these pests is not really feasible.
There have been a number of studies carried out and only in very restricted and tightly controlled environments have Dragonflies, or their larvae, been shown to be able to control pest numbers. In the open, there is no reason to suppose that Dragonflies introduced to a pest rich habitat will stay there. Indeed, they certainly will not if other aspects of the environment do not suit them.
It follows from this that your best chance of getting Dragonflies to prey on pests is to develop the habitat so that it is particularly suitable for Dragonflies, a worthwhile aim in itself! Dragonflies do have enemies. Among the species that catch and eat adult dragonflies and damselflies are birds e.
Wagtails and Hobbies , Spiders many damselflies are caught in webs , Frogs, and larger species of dragonflies which catch and eat other dragonflies and damselflies. In the larval stage, which is spent underwater, they are preyed on by fish, frogs, toads and newts, other water invertebrates — and Kingfishers see photo below. Their defences include their excellent eyesight and flying skills which can help them to evade capture.
Some are coloured black and yellow, or black and red, which is the universal warning colouration and may deter some of the bird predators. There are many legends and myths about dragonflies and damselflies from all parts of the world.
Many are evident from their common nicknames. This name may come from the way a captured dragonfly curls its abdomen as if in an attempt to sting. Another possible explanation of this name is that the big Aeshnids etc. Here they were actually feeding on the flies attracted to the horses. People seeing it made the inference that it was the dragon, being big and obvious, stinging, rather than an unseen fly biting. Naturally there is no truth in either myth Similar myths are found throughout the world.
You can find more about them by visiting Cultural Odonatology References , a site which has reference material relating to myths, legends, folklore and cultural significance of Odonata throughout the world. For more myths, and mythical names used in Europe you could visit Swedish Dragonflies where you will find a page of such items. Both these links will open in a new window.
Yes, Dragonflies do have a pair of antennae. They are very tiny and difficult to see. If you look at the photo you will just be able to see the antennae between the front of the eye and the front of the face of this Emperor dragonfly. As dragonflies rely much more on their eyesight than on a sense of touch or smell, they do not need the large antennae found on some beetles and moths.
Several species of dragonfly are known to collect in large aggregations or swarms. The wings do not narrow at the base; the forewings and hindwings differ in shape.
When they are resting, the wings are usually spread. What are the biggest dragonfly and damselfly? The Megaloprepus coerulatus damselfly of Central America has a wingspan up to 19 cm. The bulkiest known dragonfly is Petalura ingentissima from Australia, with a wingspan up to 16 cm. Extinct fossil dragonflies with wingspans up to cm have been identified.
What is the smallest dragonfly? Several dragonflies in the genus Agriocnemis have a wingspan of just mm. How strong are their eyes? A dragonfly can see all the way around itself, because its eyes have about 30, lenses. However, the human eye with only one lense can see more sharply, though only front and sides. How long have dragonflies been around? About million years.
Huge dragonflies, with wing spans up to 30 inches, were flying when dinosaurs roamed the earth. Where do dragonflies live? Dragonflies start their life in water, therefore they are often found near water: ponds, lakes, canals, streams, rivers and swamps. Some dragonflies with a short larvae cycle a few weeks also can live in rain puddles.
Since dragonflies are very good flyers they can sometimes be found a very long way from water. Do dragonflies bite? The quick, rational answer to this question is NO, don't worry about it. Just appreciate how many mosquitoes they eat for us! Dragonflies do not have teeth - they use their very strong mandibles to eat their prey. To the insect world, they are considered verocious predators, but most species would not be able to break through human skin.
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