Modeling Strain Sensing by the Gyroscopic Halteres, in the Dipteran Soldier Fly, Hermetia illucens

Dipteran insects are known to receive mechanosensory feedback on their aerial rotations from a pair of vibratory gyroscopic organs called halteres. Halteres are simple cantilever-like structures with an end mass that evolved from the hind wings of the ancestral four-winged insects form. In most Diptera, including the soldier fly Hermetia illucens, the halteres vibrate at the same frequency as the wings. These vibrations occur in a vertical plane such that any rotation about this plane imposes orthogonal Coriolis forces on the halteres causing their plane of vibration to shift laterally by a small degree. This motion results in strain variation at the base of the haltere shaft, which is sensed by the campaniform sensilla. This strain variation is, therefore, a key parameter for sensing body rotations. In this paper, we present a study of the basic mechanism of soldier fly halteres to demonstrate its use as a vibratory gyroscope. First, we use a static force sensor to determine the stiffness of the haltere,...