Selective Responsiveness in Males of Cicada orni to Conspecific and Allospecific Calling Songs (Hemiptera: Cicadidae)

Abstract

Playback experiments with natural and modified signals broadcast to specimens of Cicada orni Linnaeus 1758 were performed in order to understand selective singing responsiveness by males during acoustic chorus activity. Males showed different patterns of response to different kinds of signals. Frequently heterospecific calling signals did not elicit effective response but in several instances they were perceived as appropriate, and males replied to them. This was the case of calling song of Cicada mordoganensis Boulard 1979 which proved to be as effective as the proper song of C orni Modification in the time domain showed that males basically need to hear a minimum signal duration (echeme and interval duration) corresponding to the lowest limit of natural variation in the species. Results supported the idea that males seem to perceive variation in signals in a discontinuous manner and are unable to show selective responsiveness to small differences. Such apparent tolerance and permissiveness in male singing response to heterospecific calling songs may result from lack of selection on the response to allopatric-heterospecific signals.