The Physiology of the Tettigoniid Ear

Abstract

The thresholds for the spiracle and for the tympanal slits have been determined at a variety of angles to the body axis and show little directionality. A difference in threshold levels of 20 dB exist between the ipsilateral and contralateral whole organs in the frequency range 1− 20 kHz. Single-frame exposures of a video-tape recording show that the spiracular dimensions do not change during stridulation. In the light of the evidence, a new hypothesis for acoustic orientation behaviour is advanced.