Abstract

LARVICIDAL BIOASSAY OF FIVE TROPICAL PLANTS AGAINST AEDES AEGYPTI

Anju R Unnithan* and Geetha Unnikrishnan

Abstract

Background & Objective: Screening of plants for larvicidal activity against Aedes aegypti third instar larvae and chemical characterization of active fraction to identify a promising plant source for ecofriendly larvicides which may solve the problems related with injudicious and over application of synthetic insecticides in nature. Method: The larvicidal potential of Petroleum ether, n-butanol, ethyl acetate, acetone, methanol, ethanol, and water extracts of Lantana camara, Terminalia catappa, Adhatoda vasica, Leucas aspera & Eupatorium odoratum leaf extracts was evaluated against the third instar larvae of Aedes aegypti. Larval mortality was observed after 24 hr, 48hr and 72hr of exposure and LC50 for 24hr exposure time was determined. GC – MS analysis of active fraction was also done. Results: The highest larval mortality was found in Lantana camara petroleum ether leaf extract with an LC50 value of 48.851ppm. GC–MS analysis of Lantana camara petroleum ether leaf extract revealed the presence of around 62 compounds, of which the significant compounds were p-Cymene, Eucalyptol and Beta-Caryophyllene. Conclusion: The preliminary screening and chemical characterization provides a scientific rationale to highlight the importance of Lantana camara petroleum ether leaf extract as a source of larvicidal agents against Aedes aegypti.

Keywords: Larvicide; Aedes aegypti; LC50; GC–MS; Lantana camara; Petroleum ether leaf extract;.