Larvicidal and repellent potential of sesamum indicum hull peels extracts against culex pipiens l. (diptera: Culicidae)

Abstract

Pest control is facing economic and ecological challenges around the world as a result of human and environmental threats caused by many synthetic pesticide chemicals. Alternative pest management tools that are biodegradable and less harmful to humans, non-target species, and the environment, in general, are highly required. Plant extracts with significant insecticidal activity hold promising effects. On this basis, this present study intended to assess the efficacy of methanol, acetone, chloroform, and petroleum ether extracts of Sesamum indicum hull peels against the 3rd instar larvae of mosquito, Culex pipiens which are considered as a disease vector. The prepared plant extracts were tested for their ability to repel Cx. pipiens adults. All plant extracts had larvicidal activity against Cx. Pipiens larvae. The petroleum ether extract, on the other hand, was found to be the most efficient. The median lethal concentration (LC50) values of methanol extract were 161.66, 158.17, and 144.52 ppm after 24hrs, 48 hrs, and 72 hrs, respectively. For acetone extracts, LC50 values were 131.88, 117.45, and 104.59 ppm after 24hrs, 48 hrs, and 72 hrs, respectively. While chloroform extracts revealed LC50 values 146.89, 139.86 and 133.20 ppm at 24hrs, 48 hrs and 72 hrs, respectively. Finally, petroleum ether extracts recorded 125.95, 88.32, and 67.25 ppm at 24 hrs, 48 hrs, and 72 hrs, respectively. The extracts were found to have repellent activity against Cx. pipiens adults using LC50. In comparison to chloroform, acetone, and methanol extracts, petroleum ether was the most effective plant extract in terms of antifeedant and repellent action. Those results proved that the four extracts of Sesamum indicum hull peels have the potential to be developed as natural insecticides and repellents for the control of mosquitoes even in their simplest form. Hence, those findings may facilitate the development of low-cost alternatives to expensive organic pesticides that are relatively safe for the environment and living organisms.