Influence of species of host plants on the predation of thrips by Neoseiulus cucumeris, Iphiseius degenerans and Orius laevigatus

A leaf-disc bioassay was used to compare the predation levels of two specie s of predatory mites (Neoseiulus cucumeris (Oudemans) and Iphiseius degener ans (Berlese)) and a predatory bug (Orius laevigatus (Fieber)), on the thri ps Frankliniella occidentalis (Pergande) and Heliothrips haemorrhoidalis (B ouche), feeding on a range of susceptible plant species from twelve plant f amilies. The predatory bug, O. laevigatus, reduced the number of thrips to a greater extent than the predatory mites and all three predators showed gr eater levels of predation on F. occidentalis than on H. haemorrhoidalis. Th e level of predation caused by each predator varied among the species of pl ants; the variation was greater on the plant hosts of H. haemorrhoidalis th an of F. occidentalis.