Predation by Orius insidiosus (Heteroptera: Anthocoridae) on Life Stages and Species of Frankliniella Flower Thrips (Thysanoptera: Thripidae) in Pepper Flowers

We compared predation of Orius insidiosus (Say) on adult and second instars of Frankliniella occidentalis (Pergande) andon adults ofF. occidentalis andF. tritici (Fitch) in arenaswith pepper ßowers. Also, we compared the dispersal of these thrips in the presence and absence of the predator. For each experiment, two densities of thrips (10 and 20 total thrips) and two time exposures (10 and 34 h) were tested. Second instars were more likely to move from the ßower where they were released than were F. occidentalis adults. F. tritici dispersed more than F. occidentalis. The presence of the predator enhanced movement by thrips from ßowers in which they were released. Despite differences in preymovement,O. insidiosus successfully preyed on all types of prey that were offered. However, O. insidiosus appeared to deal differently with each type of prey. Predation of both larvae and adults was most likely to occur inside ßowers. In trials with adults and second instars of F. occidentalis, larvaewere signiÞcantlymorevulnerable topredation thanwereadults.F. tritici, themore active species, may have been vulnerable to predation because of higher rates of encounter with the predator; however, O. insidiosus may have had greater attack success against the less active F. occidentalis. The ability ofO. insidiosus to prey successfully ondifferent life stages and species of thrips in complex environments indicates that it is an efÞcient predator of thrips and an important biological control agent.