Within-Plant Distribution of Frankliniella species (Thysanoptera: Thripidae) and Orius insidiosus (Heteroptera: Anthocoridae) in Field Pepper
We evaluated the within-plant distribution of Frankliniella spp. and the predator Orius insidiosus (Say) in pepper (Capsicum anuum L.), over a range of Þeld conditions, and we conducted behavioral experiments to examine the time budgets of F. occidentalis (Pergande) and F. tritici (Fitch) females on pepper plant parts. In the Þeld experiments Frankliniella species composition varied by season and location. Still, all populations of thrips and O. insidiosus in untreated and insecticide-treated
... secticide-treated pepper were highly concentrated in the ßowers, with 82Ð99% of individuals of each taxa found in ßowers. This preference for ßowers was corroborated by laboratory-choice experiments. Adult females of F. occidentalis and F. tritici showed a strong preference for pepper ßowers over leaves and buds. In laboratory observations, females of F. occidentalis spent 3.6ϫ as much time on ßowers as on all other plant parts, and females of F. tritici spent over 6.3ϫ as much time on ßowers as on all other plant parts. Therefore, the concentration of these thrips in ßowers appears to be behaviorally based and not an artifact of insecticide applications or sampling. Using estimates of populations from ßowers of Þeld pepper is sufÞcient for understanding the local dynamics of Frankliniella spp. and the predator O. insidiosus, and for estimating the beneÞts of biological control in scouting programs based on predator to prey ratios.