INSECTICIDAL ACTIVITY OF OLDENLANDIA CORYMBOSA (L) ON THE LARVAE AND PUPAE OF ANOPHELES STEPHENSI (L)

A preliminary study was conducted in which the methanol extracts of Oldenlandia corymbosa L. leaf were tested for their larvicidal and pupicidal activities against Anopheles stephensi L under the laboratory conditions. Larvicidal activity of the crude extract or phytochemicals against different cases of vector has been studied extensively when compared to other related aspects. The 50 ppm plant extract exhibited the larval mortality of about 44.50% in the 1st instar larvae and it was reduced to 35.76%, 17.26% and 17.26% in the 2nd, 3rd and 4th instar respectively. The pupal mortality in the case of Anopheles stephensi L. was ranging from 17.26% to 78.58% after having treated with 50 to 300 ppm over the period of 24h. The present study evidents that, the higher concentration of plant products promoted high degree of mortality in the case of larvae and pupae of Anopheles stephensi L after 24h treatment. And the results suggests that the methanol extract of Oldenlandia corymbosa L. have a good potential as larvicidal and pupicidal agent against Anopheles stephensi L. As naturally occurring insecticides, these plant derived materials could be useful as an alternative for synthetic insecticides controlling field populations of mosquitoes