Effect of Plant Lectins on the Larval Development of European Corn Borer (Lepidoptera: Pyralidae) and Southern Corn Rootworm (Coleoptera: Chrysomelidae)

Abstract

Twenty-six plant lectins were tested for antiinsect properties against neonate European corn borer, Ostrinia nubilalis (Hiibner), and Southern corn rootworm, Diabrotica undecimpunctata howardi Barber, larvae. Lectins from wheat, Triticum vulgaris L., castor beans, Ricinus communis L., and camels foot tree, Bauhinia purpurea L., were lethal to neonate O. nubilalis larvae when applied topically to the diet surface as a 2% solution. The 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. No other lectins affected larval growth or mortality of O. nubilalis. Lectins from R. communis, pokeweed (Phytolacca Americana L.), and green marine algae, Codium fragile (Suringar), were toxic to neonate D. undecimpunctata howardi larvae when applied topically (2%) to the artificial diet. Several other lectins inhibited larval growth by >40% compared with the control. These lectins were from jackfruit, Artocarpus integrifolia Lamarck, hairy vetch, Vicia villosa Roth, osage orange, Maclura pomifera Rafinesque, Bandeiraea simplicifolia (Baillon), and T. vulgaris. Transformation of the genes coding these lectins could be beneficial in the development of insect resistance in important agronomical crops.