AN ELECTROPHYSIOLOGICAL STUDY ON HEARING OF THE CICADA CRYPTOTYMPANA ATRATA FABRICIUS (HOMOPTERA:CICADIDAE)

The characteristics in response to sound and directional sensitivity of the' auditory primary meurons and interneurons of the cicada cryptotympana atrata were studied with neurophy-siological techniques. These neurons are tuned to a similar characteristic frequency, which is corresponding with the dominant frequency of calling song of the cicada. They are able to code, sound intensity within the dynamic range of 40 dB above thresholds with an increment of about two spikes per 10 dB. The auditory neurons possess good directional sensitivity with threshold differences of 10-12 dB at the best frequency between contra- and ipsilateral stimulations.