Guiding BeeHow Insects Fly

Flapping Flight

The ancient order Odonata, one of the oldest extant insect groups and comprising the dragonflies and damselflies, flaps both pairs of wings separately, the two pairs beating in opposite phase. The Megasecoptera, early members of this order, probably tended to fly along a straight path with only gentle turns. Ancient dragonflies had wings spans ranging up to about one metre (the largest of all time) and were gliders. Modern dragonflies and damselflies, however, are capable of flying in any direction without turning their bodies. They are aerial predators and, despite the primitive arrangement of their wings, they are excellent fliers. It is this arrangement of the wings which causes the clacking sound which is often heard in marshes. When a dragonfly turns, its fore and aft wings hit each other, producing a characteristic clacking.
Below is a diagram illustrating one full wing-beat of the dragonfly Aeschna juncea. The upper surface of each wing is shaded.

Shown below are the flapping motions of a single wing beat of three types of insect: locust, butterfly, and beetle. The locust (top row) beats its four wings out of phase, but not as dramatically so as the dragonfly (above). The butterfly bottom row) flaps its wings in phase, because it holds them together in one aerodynamic surface. The beetle (middle row) only beats two wings, the forward pair being shields and held out of the way of the rear pair.

Beetles, in fact, prefer running to flying when they have a choice. Beetles generally are not good fliers, as the aerodynamics are spoiled by the shells which they must hold wide open, as a June beetle does as it flies around the patio lamp in summer. Several beetle species cannot fly at all, but rely on their armor and their legs to protect them.

How Insects Fly...3, March 1996