Indian Journal of Agricultural Research

Ovicidal and toxic effects of crude leaf extracts of Clerodendrum inerme, Clerodendrum splendens, Clerodendrum multiflorum, Vitex negundo and Argemone mexicana were evaluated against the castor semilooper, Achaea janata L. (Noctuidae: Lepidoptera) using different bioassay methods. Among the extracts tested, the highest ovicidal activity was observed in C. splendens as well as A. mexicana with LD₅₀ values of 7.65 and 9.14 mg⁻¹, respectively. Leaf extracts of A. mexicana and C. inerme were toxic to both third and fourth instar larvae of A. janata through topical application. However, the extracts of A. mexicana and C. inerme found to be more toxic to third instar larvae with 70 and 73 per cent mortality, respectively. The lowest LD₅₀ value of 5.33 mg⁻¹ was recorded by A. mexicana extract and was followed by C. inerme extract withLD₅₀ valueof 7.26 mg⁻¹. Present results indicated that A. mexicana and C. inerme plants have potential to use in IPM programme.