Pheromone-mediated mating in the aphid parasitoid,Aphidius nigripes (hymenoptera: Aphididae).

Mating in the aphid parasitoid,Aphidius nigripes, is mediated by a female sex pheromone that stimulates both upwind flight and courtship behavior by males. There is no evidence of any overt behavior associated with the release of the pheromone, but bioassay results, using female extracts, suggest that the pheromone is produced in the abdomen, although it may be actively released from the entire body surface. Age does not appear to have a major influence on either pheromone production by the female or on male responsiveness. However, field data suggest the presence of a strong diel periodicity in the emission of and/or receptivity to the pheromone. Laboratory bioassay results indicated diel changes in the male response but more refined techniques are needed to determine if such periodicity exists in pheromone production by females. Following mating, female pheromone production is significantly reduced. The potential use of the parasitoid sex pheromone in integrated management of aphids is discussed.