The eyes are very large and usually touch, at least at a point. The larvae have no external lamellae. No, although large dragonflies, if held in the hand, will sometimes try to bite they fail to break the skin. Nor do they attack people, though they are fearsome predators of other flying insects.
At a guess, Bacon had picked up on a folkloric name of that time. Jill Lucas which has a great deal about dragonfly folklore. Some of the larger dragonflies take 6 or 7 years! Most of this time is spent in the larval form, beneath the water surface, catching other invertebrates. The small damselflies live for a couple of weeks as free-flying adults. The larger dragonflies can live for 4 months in their flying stage. 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. Species living in bottom sediments have relatively poor eyesight, but instead use their hairs, long legs and antennae to sense prey.
By contrast, hawkers have large eyes and hunt by sight amongst plants nearer the surface. Dragonflies undergo incomplete metamorphosis ; unlike other winged insects, such as butterflies, dragonflies do not have a pupal stage and transition straight from a larva to an adult. This transition, the final larval moult, takes place out of water.
This metamorphosis is triggered by day length and temperature, and is synchronised in some species, such as Emperor Dragonfly. The final-stage larvae sit in shallow water, near the margins, for several days, getting ready for their final moult and starting to breathe air.
Most species leave the water during the morning, but hawkers do so under cover of darkness. Larvae climb up emergent vegetation, although some may walk several metres over dry land before finding somewhere suitable to emerge. After finding a secure support, they redistribute their body fluids, pushing the thorax, head, legs and wings out of the larval skin.
There is then a pause of about 30 minutes to allow their legs to harden enough for the next stage, when the abdomen is withdrawn. The wings, and then the abdomen, are expanded and start to harden.
This process leaves behind a cast skin, called an exuvia, and the whole process lasts between one hour Damselflies to three hours Dragonflies. At such times, dragonflies are especially vulnerable to predation by birds, such as the Hobby. Other hazards include rainfall, which can damage soft tissue during emergence. Tenerals are newly-emerged adult dragonflies that are weak in flight and pale in colouration. As the body and wings harden off they begin hunting for food whenever fine weather permits.
They spend about a week feeding away from water and gradually acquire adult colouration and sexual maturity. When mature, adults move back to the water to breed.
The males of some species are territorial and battle constantly to obtain and defend a suitable breeding sites. They investigate any male intruders, as well as females, which they will try to seize and mate with. The game is very simple in terms of both graphics and gameplay, but this does not stop it from being worth a look. Luckily for you, the landscape is characterized by lots and lots of hills, which you must use as ramps to gain height, speed and distance.
The ultimate goal is to gain as much ground as possible on the dragon mother, as she pursues you relentlessly. To make Dragon, Fly! The game becomes more addictive because there are various possibilities for upgrading, which result in a greater head start for the small dragon. In order to reach a higher level you must pass three challenges each time, which naturally increase in difficulty.
Gaining levels and upgrading the little dragon is one way of progressing through the game. However, as a player you can also go up in ranks. This online ranking system adds greatly to the game and you are constantly reminded of your progress. All these elements combined make Dragon, Fly! The gameplay is fun for a while, but in the end perhaps too repetitive. Whether the upgrading elements are enough to keep you hooked remains to be seen, but we fear that the game will need something extra to remain interesting in the long run.
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