VISUAL INPUT TO THE EFFERENT CONTROL-SYSTEM OF A FLYS GYROSCOPE

Dipterous insects (the true flies) have a sophisticated pair of equili brium organs called halteres that evolved from hind wings, The haltere s are sensitive to Coriolis forces that result from angular rotations of the body and mediate corrective reflexes during flight, Like the ae rodynamically functional fore wings, the halteres beat during flight a nd are equipped with their own set of control muscles. It is shown tha t motoneurons innervating muscles of the haltere receive strong excita tory input from directionally sensitive visual interneurons. Visually guided flight maneuvers of flies may be mediated in part by efferent m odulation of hard-wired equilibrium reflexes.