Tuesday, September 16, 2008

DRAGONFLY

A dragonfly is a type of insect belonging to the order Odonata, the suborder Epiprocta or, in the strict sense, the infraorder Anisoptera. It is characterized by large multifaceted eyes, two pairs of strong, transparent wings, and an elongated body. Dragonflies are similar to damselflies, but the adults can be differentiated by the fact that the wings of most dragonflies are held away from, and perpendicular to, the body when at rest.
Dragonflies typically eat mosquitoes, and other small insects like flies, bees, ants and butterflies. They are therefore valued as predators, since they help control populations of harmful insects. Dragonflies are usually found around lakes, ponds, streams and wetlands because their larvae, known as "nymphs", are aquatic. Adult dragonflies do not bite or sting humans, though nymphs are capable of delivering a painful (though otherwise harmless) bite.

Dragonfly characteristics
Male Dragonflies are capable of hovering followed by rapid acceleration. Giant dragonflies can glide for 20 meters at 10 degrees and a speed of 74 cm per second which is similar to some birds.They capture their prey by clasping them in legs studded with spikes. Prey cannot escape by diving away because dragonflies always attack from below.
Life cycle
Female dragonflies lay eggs in or near water, often on floating or emergent plants. When laying eggs, some species will submerge themselves completely in order to lay their eggs on a good surface. Most of a dragonfly's life is spent in the naiad (that is, nymph) form, beneath the water's surface, using internal gills to breathe, and using extendable jaws to catch other invertebrates or even vertebrates such as tadpoles, fish, etc. Some nymphs even hunt on land, an aptitude which could easily have been more common in ancient times when terrestrial predators were clumsier. The larval stage of large dragonflies may last as long as five years. In smaller species, this stage may last between two months and three years. When the larva is ready to metamorphose into an adult, it climbs up a reed or other emergent plant at night. Exposure to air causes the larvae to begin breathing. The skin splits at a weak spot behind the head and the adult dragonfly crawls out of its old larval skin, waits for the sun to rise, pumps up its wings, and flies off to feed on midges and flies. The adult stage of larger species of dragonfly can last as long as four months.
Pictures taken By Spera Gerardo at Pomarico (Italy), text by:

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Hello everyone and welcome in my photoblog. The photos are all taken in italy and specifically in basilicata. My small town called POMARICO is located in the province of Matera, ITALY. Good Vision! Dino.

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