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

The mirid bugs Dicyphus tamaninii Wagner and Macrolophus caliginosus Wagner and the anthocorid bugs Orius majusculus (Reuter) and O. laevigatus (Fiebe r) are abundant generalist predators in unsprayed vegetable crops of the Sp anish Mediterranean coast. We evaluated the functional response of these pr edators to greenhouse whitefly pupae and western newer thrips larvae (secon d instar) on cucumber leaf disks in the laloratory. Parameters of the rando m-predator equation obtained were compared among all predator-prey combinat ions to determine the potential role of the predators in the biological con trol of both pests in cucumber. D. tamaninii was efficient at consuming whi tefly pupae at high and low densities and thrips at high densities, and too k less time to handle either of these prey than did the other predators. An thocorid 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. tamininii may have a good action in the control of both greenhouse whitefly and western newer thrips, whereas M. ca liginosus and both Orius species may be slower in controlling whitefly and be similarly efficient in consuming western newer thrips.