Studies of Persistent Toxicity of Some Natural Products (Neem) against Pyrilla perpusilla (Sugarcane pest) in Bihar

Investigations were carried out to study the persistent toxicity of some natural products (Neem) like neem oil, Nimbecidine, Neemark and Nimbitor against Pyrilla perpusilla. The observatios recorded on mean percent protection against second. Instar larva indicated that the treatments with 2 percent Nimbecidine, 2 percent neemark and 2 percent Nimbitor persisted for five days. In percent Nimbecidine, 2 percent Nimbecidine and 2 percent Nimbitor persisted four days after application.