Insects are the most successful animal on earth, and their ability to fly is a large contributor to this fact. Flying allows them to travel great distances in relatively short time intervals. Finding food, mates and favorable habitats as well as avoiding predation are some advantages of flying. It may sound easy to describe how insects fly, however it really is not easy at all. The reason for this is virtually everything about how they accomplish flight is species specific!
A few characteristics shared by flying insects are as follows: proper muscles in the right places, the structure of the skeleton the muscles are attached to which enable a large amount of wing movement with a small change of muscle length, and the ability to control direction while flying. In addition to this, their ability to fly is temperature dependent. If the body temperature is to low sleight muscle contractions in the thorax will raise it up enabling maximum efficiency of muscle contractions. Finally and most important, all flying insects must have wings ( Pechenik, 1996 ).
The physics which permit flight in insects is similar to that of an airplane. The body and wing morphology create a higher air pressure under the wing relative to the air above the wing because the shape of the wing induces a larger air velocity above the wing than under it. It is this that causes the lift the animal needs to fly. Of course an air flow across the wings must be present for this to happen, which is created by moving the wings ( Pechenik,1996).
The types of wings and ways they are moved vary depending on the species of insect. The two major types of motion are direct and indirect movement of the wings. Direct movement involves muscles that are attached directly to the wing base. The down stroke of the dragonfly uses this kind of muscle/wing relationship. The more common indirect movement involves muscles attached to a wing joint.