Foraging for mates in the hyperparasitic wasp, Dendrocerus carpenteri: impact of unfavourable weather conditions and parasitoid age

Males of the aphid hyperparasitoid Dendrocerus carpenteri (Curtis) were att racted by a sex pheromone released by conspecific females. The intensity of this cue, and thus female attractiveness, depended both on the female's ma ting status and her age. Only virgin females younger than 2 h were consiste ntly recognized as mates by foraging males. Male age did not influence fora ging and mating success. Empty mummies, from which females had emerged with in the previous 10 min were attractive to males and examined intensively. R ain reduced the searching success of males, although the host plant Vicia f aba provided sheltered places. Wind did not reduce mating success but preve nted both sexes from leaving the host plant. Since the time of female attra ctiveness seems to be very limited, wind may have an enormous effect on the mating success of D. carpenteri in the field and thus on the population dy namics of this species.