Scientists believe that theoretically, even this speed is insufficient to keep these insects aloft, and that they must employ some other additional system. In fact, Anarsia, a kind of parasite, makes use of a method known as "beat and shake." When its wings reach the highest point in their lift, they strike against each another and then open down again. As the wings, with their string vein, open the front air current first sets up a vortex around the wings and assist with the wing beat lift force.
Many species of insects, the locusts included, take note of visual data such as the line of the horizon to determine their direction of flight and eventual destination. For determining their position, flies have been created with an even more extraordinary structure. . These insects have only a single pair of wings, but to the rear of each, there is a knob-shaped lobe known as the halter. Although the halters produce no lift force, they vibrate together with the front wings. When the fly changes its direction of flight, these wing extensions prevent it from deviating off course.