Dragonflies and Damselflies
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 Blue dragonfly | ||||||||||
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Aeshnidae - Hawkers |
The dragonfly is an insect belonging to the Order Odonata, Suborder Anisoptera and characterized by large multifaceted eyes, two pairs of strong transparent wings, and an elongated body. Dragonflies typically eat mosquitoes, midges and other small insects like flies, bees, and butterflies. They are usually found around lakes, ponds, streams, and wetlands for the reason that their larvae (known as nymphs) are aquatic. Dragonflies do not bite or sting humans.[1] In fact, they are valued as a predator that helps control the populations of insects that do, such as mosquitoes.
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General facts
Much larger dragonfly species existed in the distant past than occur on earth today. The largest, found as a fossil, is an extinct Protodonatanamed Meganeura monyi from the Permian period with a wingspan of 70–75 cm (27.5–29.5 in). This compares to 19 cm (7.5 in) for the largest modern species of odonates, the Hawaiian endemic dragonfly, Anax strenuus. The smallest modern species recorded is the libellulid dragonfly, Nannophya pygmaea from east Asia with a wing span of only 20 mm, or about 3/4 of an inch.
The Common Green Darner dragonfly (Anax junius) is nicknamed "Darning Needle" because of its body shape. It is one of the biggest and fastest-flying dragonflies, able to reach speeds of 85 km/h (53 mph).
Damselflies (Suborder Zygoptera) are often confused with dragonflies, but the two insects are distinct: damselflies at rest hold their wings together above the body, whereas dragonflies at rest hold them out, either horizontally or slightly down and forward. Also, the eyes on a damselfly are separated, while those of the dragonfly are nearly touching. Both are members of Odonata, and their life cycles are similar.
Motion camouflage
It was recently discovered that dragonflies employ an optical illusion to stalk other insects who invade their territory. A dragonfly can move in such a way as to project itself as a stationary object while speedily attacking its victims, new research suggests. These findings illustrate for the first time how dragonflies use complex camouflaging techniques during aerial combat.
Pictures of Dragonflies
- Dragonfly Photographys (http://classroomclipart.com/cgi-bin/kids/imageFolio.cgi?direct=Animals/Insects/Dragonflies)
Some common species
- Emperor Dragonfly, Anax imperator
- Black-tailed Skimmer, Orthetrum cancellatum
- Common Whitetail, Libellula lydia
- Migrant Hawker, Aeshna mixta