Seasonal abundance of primary parasitoids and hyperparasitoids associated with Acyrthosiphon pisum (Harris) and Acyrthosiphon kondoi Shinji (Homoptera: Aphididae) on alfalfa

Seasonal abundance of primary parasitoids and hyperparasitoids associated with Acyrthosiphon spp. was studied in an alfalfa field in 2000. Two species of primary parasitoids were recorded: Aphidius ervi and Praon barbatum. Mean parasitism by A. ervi and P barbatu,n peaked at 3.5% on 10 July and 13.0% on 29 June. Six species of hyperparasitoids were also collected. Rates of parasitism of A. ervi and P. barbatum reached over 90% and 80%, respectively. Dendrocerus carpenteri and Asaphes suspensus were the dominant species among hyperparasitoids.