Antipupational effect of neem oil and neem seed kernel extract against mosquito larvae of Anopheles stephensi (Liston) Murugan K.1, Babu R., Jeyabalan D.*, Kumar N. Senthil, Sivaramakrishnan S. Division of Entomology, Department of Zoology, Bharathiar University, Coimbatore - 641 046, Tamil Nadu, (India). *Corresponding author.
1Present address: Lab. of Signal Selection, National Institute of Sericultural and Entomological Sciences, Tsukuba, Ibaraki, 305, (Japan). Abstract Antipupational effect of neem oil and neem seed kernel extract (NSKE) was evaluated against Anopheles stephensi. As a result of treatment of water used for rearing, neem oil (5%) was more effective than NSKE, the larval mortality being 99.3% as compared to 65.9% with NSKE (5%). But 10% NSKE gave 89.8% larval mortality. The percentage of pupation and adult emergence appeared to be dose-dependent, being respectively 19.3 and 11.2% with 3% neem oil as compared to 93.7 and 89.6% obtained in control. No pupation occurred with 5% neem oil treatment. With 5% NSKE, the adult emergence was 20.7%, whereas in 3% neem oil it was reduced to 11.2%. With 2.5% NSKE, the adult emergence was 54.8%, but drastically reduced to 3.1% when 10% NSKE was used vis-a-vis control (89.6%). Evidently, the percentage of pupation and adult emergence were markedly reduced by neem oil and NSKE treatments, suggesting the growth regulatory effects and post-ingestive toxicity of neem extractives in mosquito control. Top |