Sexual calling behaviour, and the effects of immediate mating history and consexual presence in the seven-spot ladybird, Coccinella septempunctata

Pheromones perform a variety of functions in intraspecific communication in insects, including the identification of conspecifics, aggregation, alarm and mate-finding. Calling behaviour, in which generally females release volatile sex pheromones to attract the opposite sex, has been studied in several coleopteran families. Within the Coccinellidae, a putative calling behaviour has thus far only been identified in one species, Harmonia axyridis. In this study, a postulated calling behaviour in the seven-spot ladybird Coccinella septempunctata L. is described. We also investigated the effects of immediate mating history and the presence of conspecifics on this behaviour. Calling only occurs in females, and significantly fewer females called immediately after mating (observation started within 5 min). Of mated females that called, the number of calling bouts, durations per bout and total calling duration were not significantly different from females that had not immediately mated before. The presence of conspecific females or males did not significantly affect calling. This study provides a key step in furthering our understanding of the reproductive biology of ladybirds. Given that C. septempunctata is a widespread coccinellid, it is surprising that this behaviour has so far remained undescribed. This may be partly due to the infrequency of calling.