Effect of certain plant extracts against the mosquito, Anopheles stephensi Liston.

摘要

The effects of extracts of Leucas aspera, Ocimum sanctum, Azadirachta indica, Allium sativum and Curcuma longa on the larval mortality, pupation, adult emergence, repellency, and ovipositional deterrency of A. stephensi at 1-4% concentrations were screened. The leaf, pulp and rhizome extracts of L. aspera, O. sanctum, A. indica, A. sativum and C. longa significantly reduced larval survival. The leaf extracts of L. aspera and O. sanctum were most effective. The percentage mortality at 4% concentration of L. aspera and O. sanctum was 90 and 84%, respectively compared with 71, 68 and 54% for A. indica, A. sativum and C. longa, respectively. Significant reduction in pupation was observed in all the treatments. The leaf extract of L. aspera and O. sanctum at 1% concentration, reduced percentage of pupation and adult emergence significantly more than other treatments. This effect progressed in a dose response manner. The leaf extracts of L. aspera and O. sanctum at 4% concentration, significantly increased adult repellency to 89 and 78%, respectively, but ovipositional deterrency was significantly greater in A. indica, L. aspera and O. sanctum.