The African yam bean seed lectin affects the development of the cowpea weevil but does not affect the development of larvae of the legume pod borer

Artificial feeding assays were used to study the effect of purified galacto se-specific lectins from African yam beans (Sphenostylis stenocarpa) on dev elopment of larvae of the cowpea weevil, Callosbruchus maculatus (Coleopter a: Bruchidae) and the legume pod-borer, Maruca vitrata (Lepidoptera: Pyrali dae). Inhibition of development of C. maculatus was observed when larvae we re fed on artificial cowpea seeds containing 0.2%. 2.0% and 5.0% (wt/wt) of dietary lectin. Larval mortality was between 30% and 88%, while delays in total developmental time ranged between 7 and 13 days. The lectin had no ef fect on development of larvae of M. vitrata, when tested through topical ar tificial diet incorporation assays, except at the extremely high dose of 35 % dietary level. (C) 2000 Elsevier Science Ltd. All rights reserved.