EFFECT OF PLANT-LECTINS ON THE LARVAL DEVELOPMENT OF EUROPEAN CORN-BORER (LEPIDOPTERA, PYRALIDAE) AND SOUTHERN CORN-ROOTWORM (COLEOPTERA, CHRYSOMELIDAE)

Twenty-six plant lectins were tested for anti-insect properties against neonate Ostrinia nubilalis and Diabrotica undecimpunctata howardi larvae. Lectins from wheat Triticum vulgaris, castor beans Ricinus communis and camels foot tree Bauhinia purpurea were lethal to neonate O. nubilalis larvae when applied topically to the diet surface as a 2% solution. LC50's for lectins from R. communis, T. vulgare and B. purpurea incorporated into the artificial diet were 0.29, 0.59 and 0.73 mg/g of diet, respectively. Surviving larvae had a 50% weight loss compared with control larvae at these concentrations. Lectins from R. communis, pokeweed Phytolacca americana and green marine algae Codium fragile were toxic to neonate rootworm larvae when applied topically (2%) to the artificial diet. Several other lectins inhibited larval growth by >40% compared with the control. -from Authors