EFFECT OF MANNOSE-BINDING LECTIN FROM PEANUT AND PEA ON THE STEM BORER CHILO-PARTELLUS

A mannose-binding lectin found in vegetative tissues of peanut, Arachi s hypogaea, was compared with mannose-binding lectin from pea, Pisum s ativum, for toxic effects on larvae of the stem borer Chile partellus (Swinhoe). After 10 days, the,mortality of larvae fed on artificial di et containing 0.5% (m/m) peanut lectin was 46.2%. The mortality of lar vae fed on 1.0% peanut lectin was similar (48.1%) but insects were sig nificantly smaller than those of the 0.5% treatment. Larvae of both le ctin treatments stopped feeding within three days. Larval size and mor tality was not significantly reduced by 0.1% peanut lectin and 1% heat -treated lectin did not show toxic effects. The mannose-binding lectin from pea was not toxic to C. partellus at concentrations up to 1%. Pe anut lectin bound to the apical membranes of columnar epithelial cells in the mid-gut of C. partellus. This suggests that peanut lectin has an antinutritive action and that it may protect vegetative tissues of peanut against insect pests.