Acoustic signals in cicada courtship behaviour (order Hemiptera, genus Tibicina)

Abstract

During pair formation, cicadas produce acoustic signals that allow sexual partners to meet. The male is generally the emitter, producing calling songs at long range and courtship songs at short range, and the female generally the receiver. The male–female courtship behaviour of seven taxa belonging to the Palaearctic genus Tibicina is described here for the first time. Male courtship songs consisted of a succession of groups of pulses arranged in two sub-groups. They were short in duration with strong amplitude variations. In all taxa, courtship songs were preceded by a series of 1–5 audible wing-flicks. Differences in courtship song structure between two pairs of sympatric species, respectively T. corsica corsica/T. nigronervosa and T. corsica fairmairei/T. tomentosa, suggest that courtship signals could act as distinctive species mating recognition systems. In response to male acoustic signalling, females of T. c. corsica, T. c. fairmairei and T. nigronervosa produced audible wing-flicks such that both sexes established an acoustic duet ending in physical contact. In addition, males and females of T. tomentosa produced silent wing-flicks, a previously unknown behaviour, which could facilitate pheromone diffusion. Females did not exhibit a species-specific temporal pattern in acoustic reply to male courtship song and female wing-flick behaviour does not seem necessary for pair formation. Nevertheless, this strategy through male and female signalling ensured a reciprocal phonotactic approach that probably enhanced the likelihood for the two sexes to meet in complex habitats.