Abstract

LETHAL EFFECT OF BOTANICALS AND BIO-CONTROL AGENTS ON THE LARVAE OF AEDES AEGYPTI

K. M. Remia, S. Logaswamy and R. Shanmugapriyan*

Abstract

The present study is aimed to evaluate the median lethal dose of botanical extracts of Ocimum gratissimum, Hyptis suaveolens, bio control agent Bacillus thuringensis isralensis against the larvae of Aedes aegypti. The LC50 value of O.gratissimum was 55.28 and 59.62 ppm against third and fourth instar larvae. H. suaveolens required 59.07 and 79.63 ppm to produce fifty percent larval mortality during the age of third and fourth instar. 2.18 and 3.17 ppm of Bacillus thuringensis isralensis registered as LC50 value on second and third instar larvae. The synthetic chemical pesticide chloripyrifos achieved fifty percent kill at 5.79 and 6.41 ppm. Among the treatments, Bacillus thuringensis isralensis required least dose to kill the larvae after 24 hours of treatment.

Keywords: Median Lethal Dose (LC50), Larvicidal Effect, Botanical Extracts, Bacillus thuringensis isralensis.