Acoustic mimicry and disruptive alternative calling tactics in an Australian bushcricket (Caedicia; Phaneropterinae; Tettigoniidae; Orthoptera): does mating influence male calling tactic?

摘要

Male calling and searching tactics are described for a duetting Australian bushcricket, Caedicia sp. 12 (Phaneropterinae; Tettigoniidae; Orthoptera). The repertoire of Caedicia sp. 12 consists of the calling song and, by nonduetting males, a series ofcalling tactics that include short-click calling, disruptive over-singing and a call mimicking the entire duet. Nonduetting males respond to the production of a duet by another male and a female with short-click calls that mimic the female call at the conclusion of a duet. By manipulating the male's mating history, it is found that this form of calling behaviour is more likely to occur within the male's 6-day postmating refractory period; the low cost tactic allows males to re-mate during spermatophorereplenishment. Males also produce disruptive calls in response to a duet, where the male may over-sing the duetting male's signal or produce a call that appears to mimic the entire duet; the male produces a calling song followed by a short signal that has the same latency as the female's reply within a duet. Males also over-sing crucial elements of the duetting-male's song that are normally critical for the female's conspecific recognition. There is no evidence that females search for the duetting malepartner, but males unable to enter a duet will search for the call of a responding female. Searching by males is more common when these males are producing disruptive calls. Alternative male calling tactics are discussed as a set of conditional strategies for securing unmated females.