not in Young The biological effect of plant extracts on the two predators C. carnea and C. undecimpunctata was studied in the laboratory. Treated B. brassicae was offered to the newly hatched larvae of the two predators. The rate of prey consumption and duration of the larval instars of the two predators were slightly affected as a result of the treatments of the plant extracts. Adults of the aphid parasite D. Rapae and the whitefly parasite E. Mundus were exposed to the plant extracts via feeding on treated honey droplets or parasitized treated hosts. Mortality percentages of D. Rapae fed on honey contaminated with plant extracts were 50 and 80% for extracts of Melia fruits in ethanol and in petroleum ether, respectively. Mortalities in parasites developed in hosts treated with plant extracts of Neem fruits in ethanol and Melia flowers in petroleum ether in were 33.3 and 81.5%, respectively. Similar results were obtained when E. Mundus received the same treatments of the plant extrac! ts. Coccinella undecimpunctata (Coccinellidae); Bemisia tabaci (Aleyrodoidea); Brevicoryne brassicae (Aphidoidea); Eretmocerus mundus (Aphelinidae); Diaretiella rapae (Braconidae); Chrysoperla carnea (Neuroptera). Bemisia tabaci, Brevicoryne brassicae, Chrysoperla carnea, Coccinella undecimpunctata, Diaretiella rapae, Eretmocerus mundus: Development, Fertilizers and pesticides, Botanical insecticide effects. Arthropods; Beetles; Hymenopterans; Insects; Invertebrates; True Bugs. none