LARVICIDAL EFFICACY OF THE SYNERGISTIC COMBINATION OF ALLIUM SATIVUM AND CYMBOPOGON CITRATUS AGAINST AEDES SPECIES LARVAE

ABSTRACT

Mosquitoes are tiny flying insects of great importance as vectors to many pathogenic organisms, including viruses. Aedes species is a primary vector of the dengue virus that causes dengue fever, which is a globally important disease, threatening people in developing countries. Resistance of vectors to larvicides and insecticides have brought about different attention like using natural botanicals as a means of controlling mosquito vector population. In this research, the larvacidal efficacy of the synergistic combination of Allium sativum and Cymbopogon citratus against Aedes larvae was investigated and the phytochemical constituent present in this combined solution was also evaluated. Ten healthy larvae breeded in the insectary section were tested with three different concentrations (500ppm, 750ppm, 1000ppm) and one control. Larvae was exposed to test concentration for a total of 72 hours under recorded temperature and relative humidity. Mortality of these larvae was recorded after 24, 48 and 72 hours respectively. The results revealed that this synergistic activity showed high larvicidal activity in each concentration. 1000ppm of test concentration recorded 100% larval mortality after 72 hours of exposure. Probit analysis which was done at 95% confidence limit after 72 hours, version 21.0 and it recorded  to be 123.792ppm and value to be 459.086ppm. Phytochemical screening revealed the presence of Carbohydrate, Flavonoids, Alkaloids, Steroids and Tannins in the synergistic combination of Garlic and Lemon grass. The synergistic activity as seen from the study showed a good larvacidal potency. There is need for more research to discover the synergistic activity of the combination of other plant extracts and identify specific phytochemicals that show larvacidal activity against Aedes larvae.