Calling pattern and properties of neuro-muscular property in black cicadae

The black cicadae (C.atrata Fabricius),the calls are of the complex-and single-pulse types (CP-and SP-call) possessing respectively properties of the calling and courtship song.In the CP-call each sound-pulse consists of three subpulses,while in the SP-call there is only one single pulse.Both are a monotone sound with the principal frequency at about 5000 Hz as the dominant tone,but the amplitudes of principal frequencies in the CP-call are 10.5 dB in average higher than those in the SP-call.Although the waveforms of neuro-musclar activeties of sounding movements are similar in two kinds of calls,the sounding movement of CP-call is characterized by gradual onset of about 50 ms developing into the steady period,while the start of the SP-call is quick.In the sounding movements of SP-call,the neuromusclar activeties are stronger with longer action periods,the duration of action potentials,amplitudes of after potentials and EMG are respectively 52.8%,88.8% and 26.3% in average larger than those within the steady period of CP-call,while the latent priod and repetition period of spund-pulses are 49.5% and 38.5% in avearge slower.