LARVICIDAL PROPERTIES OF THREE INDIGENOUS PLANT OILS ON THE MOSQUITO AEDES AEGYPTI

Abstract

Volatile oils of three Nigerian plants Ocimum gratissimum L., [Lamiaceae] Cymbopogon citratus (DC) Stapf [poaceae] and Ageratum conyzoides L. [Asteraceae] were screened for larvicidal activity against laboratory reared larvae of the yellow fever mosquito Aedes aegypti L. Twenty (20) fourth instar larvae per 100 ml solution of each concentration were used and the toxicity of the oils compared with endosulfan, a commercial insecticide. Mortality was observed after 24 hours exposure. All the oils demonstrated complete larvicidal action at varying concentrations but were less potent than endosulfan. The oil from A. conyzoides was the most potent, giving 100% mortality at 120 ppm while oils from C. citratus and O. gratissiumum resulted in complete mortality at 200 and 300 ppm respectively. The study gave an insight into the possibility of formulating suitable preparations from the essential oils of these plants for use in mosquito control programme.


Key Words: Volatile oils, Ocimum gratissimum, Lamiaceae, Cymbopogon citratus, Poaceae, Ageratum conyzoides, Asteraceae, larvicidal activity, Aedes aegypti L.


Nig. J. Nat Prod. And Med. Vol.5 2001: 30-33