Ovicidal and larvicidal activities of some plant extracts against Aedes aegypti L. and Culex quinquefasciatus Say (Diptera: Culicidae)

Objective: To evaluate the ovicidal and larvicidal activities of hexane, chloroform and\udmethanol extracts of Gymnema sylvestre, Scilla peruvina, Rubia cordifolia (R. cordifolia) and\udElytraria acaulis roots against the eggs and larvae of Aedes aegypti L. (Ae. aegypti) and Culex\udquinquefasciatus Say (Cx. quinquefasciatus) at different concentrations of 62.5, 125, 250 and\ud500 mg/L.\udMethods: The plant materials were shade dried in the laboratory for one week and then coarsely\udpowdered. The root powder of each plant (500 g) was sequentially soaked in hexane,\udchloroform and methanol for 96 h with intermittent shaking. After 96 h, the solution was\udfiltered and the filtrate was concentrated under reduced pressure by using rotary vacuum\udevaporator. All the crude extracts thus obtained were stored in air tight glass vials and Petri\uddishes.\udResults: The ovicidal activity results showed that the methanol extract of R. cordifolia root was\udthe most potent compared to other with 82.40% and 70.40% activity against the eggs of Cx.\udquinquefasciatus and Ae. aegypti, respectively, at 500 mg/L concentration similarly, methanol\udextract of R. cordifolia root also recorded the highest larvicidal activity with LC50 and LC90\udvalues of 95.69, 347.96 mg/L against Cx. quinquefasciatus and 102.23, 350.20 mg/L against\udAe. aegypti larvae, respectively.\udConculsions: Hence, methanol extract of R. cordifolia root can be probed further for effective\udbiological control of mosquitoes