Courtship sequence and evidence of volatile pheromones in Phasgonophora sulcata (Hymenoptera: Chalcididae), a North American parasitoid of the invasive Agrilus planipennis (Coleoptera: Buprestidae)

Abstract

AbstractPhasgonophora sulcata Westwood (Hymenoptera: Chalcididae) is a North American parasitoid now using Agrilus planipennis Fairmaire (Coleoptera: Buprestidae) as a novel host, and may prove useful in biocontrol. Unfortunately, information is lacking regarding mating and the presence of pheromones, which may be important when attempting to exploit this parasitoid within a management context. Herein we used olfactometer assays and behavioural observations to determine the courtship and mating sequences of P. sulcata. A significantly higher proportion of males oriented towards females over the control arm containing filtered air in an olfactometer regardless of the age classes of females or males examined. We also observed four pre-copulatory behaviours that were consistent in all mating pairs. Our results indicate that courtship may be mediated by male perception of female-produced pheromones. Understanding the courtship sequence may be useful in rearing laboratory populations, while the putative pheromones may be useful in detection and retention of P. sulcata populations.