Sensory Control of Abdomen Posture in Flying Locusts

Abstract

1. A flying tethered locust elevates its abdomen slightly in response to increased, and depresses it greatly in response to decreased, velocities of the relative wind over the head. 2. The wind-velocity dependence and time course of abdomen movement are very similar to those of forewing twist control on the downstroke. The two responses probably work in concert to rotate the animal into a dive when flying speed has fallen critically close to staffing speed. 3. The wind-velocity monitor is provided by a specific group of cephalic wind-receptor hairs. 4. The abdomen response is almost completely absent in tethered locusts which are temporarily flightless, suggesting the presence of a neuronal switch operated by the flight mechanism.