UNUSUAL ABDOMINO-ALARY, DEFENSIVE STRIDULATORY MECHANISM IN THE BUSH-CRICKET PANTECPHYLUS-CERAMBYCINUS (ORTHOPTERA, TETTIGONIOIDEA, PSEUDOPHYLLIDAE)

The bushcricket Pantecphylus cerambycinus has two types of stridulator y mechanisms and acoustical signals. The elytro-elytral mechanism typi cal for tettigonioid bushcrickets is used to produce a narrow-band cal ling song (peak frequency 15 kHz). An abdomino-alary mechanism is used for disturbance stridulation. Its stridulatory file is situated on th e hind edge of the abdominal tergites and consists of 50-70 parallel r idges, covering the whole width of the tergite. The broad-band sound ( peak frequency 10 IrHz) is produced by the contact between the file an d ribs situated on the upper side of the hindwings which are folded in such a way that their upper side is directed toward the tergites. Def ensive stridulation in bushcrickets is reviewed here, and its function and evolution discussed in the context of predator avoidance strategi es. (C) 1996 Wiley-Liss, Inc.