Predation by the assassin bug Pristhesancus plagipennis (Walker) (Hemiptera: Reduviidae) of Helicoverpa armigera (Hubner) (Lepidoptera: Noctuidae) and Nezara viridula (L.) (Hemiptera: Pentatomidae) in the laboratory

The predatory capacity of the Australian assassin bug Pristhesancus plagipennis (Walker) was measured in the laboratory using a predation arena. Each juvenile instar of Helicoverpa armigera (Hubner) and Nezara viridula (L.) was presented as prey to each P. plagipennis instar to provide a series of predator/prey combinations. The number of insects killed or eaten by each predator instar was recorded for each predator/prey combination. The rate of predation on both prey species increased exponentially with predator development. First- and second-instar P. plagipennis were limited in their ability to capture prey larger than second-instar H. armigera and third-instar N. viridula. Third-, fourth- and fifth-instar P. plagipennis were able to prey on the widest spectrum of prey instars. None of the P. plagipennis nymphal stages were capable of preying on fifth instars of either H. armigera or N. viridula. The data suggest that nymphs of P. plagipennis have the potential to be used as an augmentative biological control agent against these pests.