Functional response of four Heteropteran predators preying on greenhouse whitefly (Homoptera: Aleyrodidae) and western flower thrips (Thysanoptera: Thripidae)

Abstract

The mirid bugs Dicyphus tamaninii Wagner and Macrolophus caliginosus Wagner and the anthocorid bugs Orius majusculus (Reuter) and O. laevigatus (Fieber) are abundant generalist predators in unsprayed vegetable crops of the Spanish Mediterranean coast. We evaluated the functional response of these predators to greenhouse whitefly pupae and western flower thrips larvae (second instar) on cucumber leaf disks in the laboratory. Parameters of the random-predator equation obtained were compared among all predator-prey combinations to determine the potential role of the predators in the biological control of both pests in cucumber. D. tamaninii was efficient at consuming whitefly pupae at high and low densities and thrips at high densities, and took less time to handle either of these prey than did the other predators. Anthocorid bugs were efficient at consuming thrips at low and high densities, but did not performed well as predators of whiteflies. M. caliginosus was less efficient when consuming whiteflies but performed better when preying on thrips. It is concluded that D. tamaninii may have a good action in the control of both greenhouse whitefly and western flower thrips, whereas M. caliginosus and both Orius species may be slower in controlling whitefly and be similarly efficient in consuming western flower thrips.