Pantecphylus (Pantecphylus) cerambycinus Karsch, 1891

Calling song and elytro-elytral stridulatory organ
The calling song is produced at night by an elytro-elytral stridulatory mechanism, typi- cal of tettigonioid bushcrickets. The song con- sists of sequences of pairs (often 10-14) of syllables (Fig. 1A; the syllable duration is about 50 ms; intrapair syllable period has a meanof162ms[range115-225 ms;n = 1051; interpair syllable period has a mean of 559 ms [range 313-1,057 ms; n = 931; n = 3 males; T = 2l°C-26°C), separated by inter- vals of several seconds. The frequency spec- trum of the song (Fig. 2A) showed a peak at about 15 kHz (bandwidth 10 dB below peak 6.3kHz).

The stridulatory file on the lower side of the left elytron contains about 90 teeth (Fig. 3A,B; one male studied: 921, that are brought into contact with the scraper on the inner edge of the right elytron (Fig. 3C) for sound production.

Defensive stridulation and abdomino-alary stridulatory organ
A completely different mechanism is used for defensive stridulation than for the calling song. If a n animal is disturbed (e.g., taken a t the pronotum), it moves its abdominal seg- ments backward and forward. During these movements, the sclerotized, broad, and finely serrated hind edges (Fig. 3D-I) of the terg- ites are brought into contact with the small ribs or teeth on several anal veins of the hind wings. The ridges on the tergites (spaced about 5 km) are the file, and the ribs are considered to be the plectra. The ribs are situated on the upper side of the wing. In a resting position, however, the wings are folded in such a way that the upper side lies above the tergites and is directed downward.

Since a regular change of two sounds with different amplitudes in a rhythm of about 1.6 Hz (mean; range 0.8-2.6 Hz; n = 26 move- ments, 1male; Fig. 1B)was observed, sound is probably produced during inward and out- ward abdominal movements. Sound impulses are separated by larger intervals (impulse interval 0.56 k 0.29 ms, mean 2 s.d.; n = 185) during the high-amplitude parts of the song (peak frequency 11.2 kHz, band- width 10 dB below peak 27 kHz), whereas during the low-amplitude part (peak fre- quency 11.2 kHz, bandwidth 10 dB below peak 28 kHz) they follow each other very closely (Fig. 1B). Differences between both parts were also observed in the frequency spectrum. The high-amplitude part was dis- tinctly louder in the low-frequency range (up to 50 kHz), whereas the low-amplitude part was louder in the upper frequency range (Fig. 2B). [1]

References