Dragonflies are species of predatory insects belonging to the taxonomic suborder Epiprocta. It is 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 because their larvae, known as "nymphs", are aquatic. Dragonflies do not normally bite or sting humans, though they will bite in order to escape, if grasped by the abdomen. They are valued as predators that help control populations of harmful insects.
Immature dragonflies have six spindly legs, and a body that is only a few times longer than it is wide. They have two fairly big eyes. Some of their mouthparts are modified to shoot forward and grab prey. They breathe water through gills in their abdomen, and can squirt this water out fast to give themselves a quick jet-propelled movement. Adult dragonflies are easy to recognize. They have long thin bodies, very large eyes, and they hold their 2 pairs of wings out flat on either side. Their legs sometimes have many long stiff hairs. Immature dragonflies are usually brown or greenish, and sometimes have algae growing on them. Adult dragonflies can be very colorful, some are red, blue, yellow, or green.
Dragonflies undergo incomplete metamorphosis with the female dragonfly typically laying eggs water. They mate in a circular or "wheel" position. The male dragonfly transfers sperm from its primary set of genitalia at the tip of its abdomen to the secondary set at the base of its abdomen. When the male finds a female it grasps it by the top of its head. The female then reaches the tip of her abdomen around to male's penis. Sperm is transferred to the female's ovipositor and the eggs are fertilized. This can be a long process. Because the female can mate more than once, part of the time is spent while the male removes the sperm of other males with specialized organs called hamules. Only then can it be sure that it is his sperm that has fertilized the eggs. Many species remain linked together until the female is finished laying her eggs. In others, the male hovers nearby to guard the female until she is finished. Dragonflies always perch with their wings flat and spread apart, while Damselflies (close relatives) usually hold their wings together over the body when they are at rest. The exceptions to this rule are the Damselflies known as spreadwings, which keep their wings angled away from their bodies at rest. Dragonflies regulate body temperature by assuming different postures, its a way of holding their bodies, and selecting specific perching sites. In cool weather they land on sun-facing perches. In hot weather they avoid overheating by sticking the abdomen almost straight up in the air to expose the least possible body surface area to the hot sun.
Dragonflies specialize in different kinds of hunting techniques. The larva stage is characterized by three basic strategies. Some stalk their prey in vegetation (climbers). Others lie in the mud and debris at the bottom of a pond and wait for prey (sprawlers). One species burrows itself completely in the mud (burrower). While the prey of the larvae is mostly other aquatic insects, some of the larger nymphs attack tadpoles and small fish. The adult dragonfly is a formidable hunting insect. Incredibly agile, it uses the basket formed by its legs to catch insects on the fly. It eats mainly mosquitoes, midges, and other small flying insects. Dragonflies eat several different kinds of insects. They catch their prey with their six legs. Their favorite prey are flies and mosquitoes. They are high in protein and very good for the dragonfly. The dragonfly will most likely be hunting on sunny days. If there is a day that the dragonfly needs food, and is not sunny, then it may eat a dead fly or mosquito. 
Males are frequently more brilliant than females and often have different colors and patterns as well. They come not only in red, fuchsia, orange, pink, blue, gold, saffron, black, emerald, maroon, earth tones, and more, but also in metallic colors. Some have colored, spotted or banded wings; others may have clear wings but clubbed abdomens or a spike on their tail. And, no, they do not sting or bite. They have mouths that they do use to bite their prey (mostly mosquitoes and gnats) The newly emerged adult (commonly referred to as teneral) may take up to 1-2 weeks to develop its full color.
Common Whitetail male
(Aeshna constricta) Family: Aeshnidae.
- dragonflies written by G. S. Hammond, and T. A. Dewey
- dragonfly anatomy written by Nelson, B., Thompson, R. & Morrow, C
- reproduction of dragonflieswritten by multiple authors
- ecology of dragonflies written by Twin Groves
- colors of dragonflies written by multiple authors
- intro written by enchanted learning