Bioefficacy of Duranta erecta leaf extract on yellow fever and dengue vector, Aedes aegypti Linn. in Nigeria

Ovicidal and Larvicidal Activities of Ethanolic Leaf Extracts of Three Botanicals Against the Malaria Vector - Anopheles Gambiae

“…The complete ovicidal activity might be as a result of the plant extract being able to block the micropyle region of the egg, thereby preventing the exchange of gases, which eventually killed the embryo in the egg. The disturbance with egg cytoplasm was reflected in the form of dead eggs with black spot stage due to the arrest of further development of embryo inside the egg [19]. T. procumbens and P. purpureum in this study, also displayed a potential of being used an ovicide in mosquito control.…”

“…The phytochemicals could have either exhibited synergistic or additive effects when used in their crude form. Secondary compounds of plants may jointly or independently have activity against mosquito targets from their ovicidal and pupicidal, activity against the adult and inhibition of growth activity [19]. D. erecta showed the highest larvae mortality in all the tested plant which predisposed it as potential larvicide for mosquito control.…”

“…Few studies have been published on the bio-efficacy of D. erecta against some different developmental stages of mosquitoes. The bio-efficacy of its leaf extracts only on the eggs and larvae of the yellow fever and dengue vector-Aedes aegypti [19] and its efficacy as a larvicidal agent against Culex quinquefasciatatus [20] have been reported. Pennisetum purpureum commonly known as napier grass or elephant grass, is a native grass species in the tropical grasslands of Africa which is spreading rapidly in many parts of the world.…”

“…The mosquito larvae were hatched from the egg colony using modified methods of Agwu et al [19]. The eggs were washed with 5 ml of 0.01% formaldehyde solution for 30 minutes in a 500ml distilled water, as a precaution against possible microsporidian infections which might interfere with the normal development of the immature stages of mosquitoes and soaked in water to facilitate hatching.…”

“…Similar studies on the ovicidal activities of plants belonging to different families against Anopheles mosquitoes have been reported by various authors with a concentration dependent increase. In the test of the ovicidal potential of D. erecta aqueous leaf extracts against the Dengue vector, Aedes aegypti a concentration dependent increase was recorded with an LC50 value of 340.085 PPM [19]. Similar findings have been documented in Boswellia dalzielii leaf extracts [61], ethanolic extract of Artemisia annua [62], leaf acetone, ethyl acetate, and methanolic extracts of Aegle marmelos, Andrographis lineata and Cocculus hirsutus [63], methanolic leaf extract of Cassia fistula [64], leaf extract of Acalypha indica [65] and those of crude hexane, benzene, chloroform, ethyl acetate, and methanol solvent extracts of Delonix elata [60] against Anopheles species.…”