A study of residual toxicity of some plant extracts on rice weevil

Abstract

The rice weevil Sitophilus oryzae attacks mostly stored grains like wheat, maize and rice. Both the adult and larval stages destroy the grain by boring into it and reducing it to husk. The grain loss is huge therefore an eco-friendly approach to control the pest is needed. Plant products are a good solution. Seed extracts of Annona squamosa, Glycine max, Ricinus communis and Helianthus annus were used for control of pest. In the evaluation of residual toxicity it was observed that the seed extract of sunflower (Helianthus annus) was most effective and protects the wheat grain up to 90 days of treatment (90 DAT).