Zoology

Dragonfly Life Span



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The dragonfly ("Odonata Anisoptera") leads a fleeting, yet intense existence. It's life span ranges from less than a year to four or five years, even when you add the larva and adult stages together, despite being one of the greatest hunters in the insect world. It is built for speed, however, so a dragonfly's time on earth is anything but dull.

== Larva ==

A female dragonfly will lay her eggs in water, sometimes attaching them to aquatic vegetation in a lake, pond, swamp or other fresh water source. A nymph (larva) can take anywhere from a few months to three or four years to grow to adulthood, depending on the species. Most of a nymph's time is spent eating other aquatic creatures, including some small fish, and molting (shedding skin) several times as it grows.

When the nymph has grown enough to transform into an adult, it climbs above the water's surface and expands its body with air, molting one last time. After crawling out of the nymph shell, the new adult expands its wet wings and then must wait a few hours as the sun dries its body and hardens the wings, preparing them for flight.

This direct larva-to-adult change bypasses the normal cocooning pupa stage that most other insects endure, such as butterflies and moths.

== Adult ==

An adult only lives about four to seven weeks, but some have been known to survive for up to six months if the weather is optimal and predators do not eat them. However, usually the first cold spell of autumn will kill it off, allowing just enough time to find a mate, copulate, and lay eggs.

The dragonfly is a voracious eater and fills its waking hours hunting, primarily using its large compound eyes. It can see the slightest movement of its prey from a distance, and it eats only other flying insects, including the bane of human existence, mosquitoes.

Dragonfly wings are quite strong, reportedly allowing speeds of 19 to 38 miles/hour (30 to 60 kilometers/hour). Dragonflies are the helicopters of the insect world, as they are able to hover, fly backwards, and perform various other aerial feats. One must wonder if this amazing agility evolved out of necessity, due to the short life span.

One of the earliest and (formerly) largest insects on earth, dragonflies have been around for about 300 million years. One Prehistoric dragonfly fossil sported a wingspan of approximately 30 inches - more than two feet!

== Dragons vs. Damsels ==

Do not confuse the dragonfly with its frailer cousin, the damselfly ("Odonata Zygoptera"). The best way to tell them apart is the watch the wings when at rest: The dragonfly will spread its wings to the sides, while the smaller damselfly will tuck them over its back, like many other insects. Also, the dragonfly's wings do not narrow at the base, like those of the damselfly.

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