Bioacoustics and neurobiology of communication in the tettigoniid Neoconocephalus robustus.

The production and reception of biologically significant sounds was examined in Neoconocephalus robustus males and females in order to better understand their mechanisms of communication.Wave form and spectral analyses were made on the stridulatory signal by using a computer-based digital signal processing system. MITSYN. The results revealed a narrow band of carrier frequencies with a peak energy level at X kHz, which derives mainly from the rate of scraper-file contact on the wings. The call signal remains unmodulated in frequency and amplitude, and uninterrupted for periods of up to 28 min. The sound pressure level of the call signal ranges from 104 to 121 dB at 1 to 10 cm. Estimates of the amount of metabolic energy expended during stridulation suggest that N. robustus males are highly efficient organisms which are capable of converting a significant portion of this energy to sound power. Auditory sensitivity of male and females was studied by electro-physiological recordings from the tympanic nerves and cervical connectives anterior to the prothoracic gang-Iron. The results revealed a high frequency audiogram, showing greatest sensitivity in the range of the carrier band and heighten sensitivity from about 6 to 25 kHz.