Potential use of Dicyphus hesperus knight (Heteroptera : Miridae) for biological control of pests of greenhouse tomatoes

The potential of Dicyphus hesperus Knight as a predator of greenhouse white fly Trialeurodes vaporariorum (Westwood), and two-spotted spider mites, Tet ranychus urticae Koch, was assessed in the laboratory and in a tomato green house. D. hesperus adults fed readily upon both pest species in the laborat ory, and nymphs completed development from egg to adult on either whitefly or mites. Whitefly, however, were a superior food for growth and developmen t of D. hesperus compared to mites. Development time was shorter and result ing adult body size was larger for nymphs reared on whitefly compared to th ose reared on mites. In a greenhouse release, adults oriented to and ovipos ited on whitefly-infested sentinel plants but did not orient to mite-infest ed sentinel plants. D. hesperus adults oviposited on greenhouse tomatoes an d their progeny completed development in a greenhouse in which both whitefl y and mites mere present. The results are discussed as they relate to the u se of D. hesperus for biological control of pests of greenhouse vegetables.