KNOCKDOWN AND REPELLENT EFFECT OF MOSQUITO COILS FORMULATED FROM CITRONELLA (Cymbopogon nardus), PIGNUT (Hyptis suaveolens) AND AFRICAN BASIL (Ocimum gratissimum) AGAINST AEDES AEGYPTI

Abstract

Abstract Mosquito coils were formulated as insect repellents using Citronella (Cymbopogon nardus), African Basil (Ocimum gratisimum) and Pignut (Hyptis suaveolens) . The mosquito coils were formulated using the crude leaves of the plants at three different concentrations (10 g, 15 g and 20 g). The leaves of the plants were formulated in combination with other ingredients which served as binders, fillers, diluents and preservatives. The efficacy of the repellents produced using the leaves of the plants was determined against Aedes aegypti at three different concentrations (10 g, 15 g and 20 g). The mosquito efficacy assessment test carried out on the formulated mosquito coils showed that the coil with Cymbopogon nardus had knockdown time (KT50) of 40, 45 and 37 minutes for the 10 g, 15 g and 20 g concentrations respectively; Ocimum g ratissimum had KT50 of 80, 69 and 55 minutes at 10 g, 15 g and 20 g concentrations respectively while Hyptis suaveolens had KT50 of 12, 23 and 27 minutes at 10 g, 15 g and 20 g concentrations respectively. The coil with the active ingredient of 10 g of Hyptis suaveolens showed the best activity with KT50 of 12 minutes. Analysis of variance (ANOVA) shows that there were significant differences (P<0.05) among the three different mosquito coils and control. There was also a significant interaction between the knockdown activity of the mosquito coils and time. These results suggest that these plants are potential mosquito repellents and can be used in insect repelling products. They may be alternatives to the commercial mosquito coils of synthetic source> < 0.05) among the three different mosquito coils and control. There was also a significant interaction between the knockdown activity of the mosquito coils and time. These results suggest that these plants are potential mosquito repellents and can be used in insect repelling products. They may be alternatives to the commercial mosquito coils of synthetic source.