Behavioural switch in the sex pheromone response of Nasonia vitripennis females is linked to receptivity signalling

The benefits for insects using chemical information may depend on their physiological state and the behavioural context in which the chemical stimuli are perceived. Hence, insect behaviour is often characterized by olfactory plasticity. Mechanisms triggering changes in the postmating behaviour of insect females are typically mediated by constituents of the male ejaculate. Here we show that the behavioural switch displayed by mated females of the jewel wasp Nasonia vitripennis in response to a male abdominal sex pheromone is independent of the transfer of a male ejaculate. Rather, our results suggest a pheromone interaction in that prior exposure of a female to one pheromone and her subsequent receptivity signal modulated her response to a second one. We tested the pheromone response of females that had been experimentally prevented from receiving sperm or from experiencing certain elements of the male courtship behaviour. We show that the behavioural switch in N. vitripennis females is linked to the receptivity signal shown by females in response to a male-derived oral aphrodisiac during precopulatory courtship.