It is very difficult to estimate the speed of insects in flight but it is thought that some dragonflies can reach 30 miles an hour. Dragonflies are easily the most skilled fliers of the insects. You may have seen them on a summer’s evening along the river bank, flitting and darting in vivid flashes of beautiful iridescent colour. You can see from their shape that they are well adapted for strong flight and acrobatic manoeuvres to catch other flying insects. They are equipped with two pairs of powerful wings. The very elongated body streamlines the dragonfly and helps to stabilize it in flight. As you might expect, a predatory insect that weaves and dives after its prey in the air must have good eyesight. The dragonfly’s head is dominated by an enormous pair of compound eyes.
The dragonfly is another insect that develops by incomplete metamorphosis. This is to say that, on hatching, the larva resembles its parent with only slight modification so that it can lead a life in a different environment. The female dragonfly lays her eggs in water. The larvae, or nymphs, lead an underwater life for two years before they finally emerge to change into adults. The nymph is as much a greedy predator as its flying parent although not so active. It creeps stealthily among aquatic vegetation and catches the fry of fishes, tadpoles and other insects. It seizes its prey using a especially extendable jaw called a mask. At rest this is folded up under the head and partly covers the face. Once a young fish swims within range the mask is flashed out and pair of claws closes on to the prey to secure it.