Evaluation of Larvicidal Activity of Aqueous Extracts of Leaves, Root, Stem of Plumbago zeylanica Plant on Aedes aegypti

Abstract

The purpose of this study was to determine the larvicidal effect of aqueous extracts of different parts of the Plumbago zeylanica plant on the dengue vector, Aedes aegypti. This research assessed P. zeylanica for its larvicide activity against A. aegypti larvae. Five different concentrations of hot and cold aqueous extracts of root, leaf, and stem powders of P. zeylanica were separately prepared. The larvicidal effect of these extracts was assessed against early 1st, 3rd, and 4th instar larvae of Aedes aegypti. Mosquito larvae were sampled, larval populations were monitored before and after application of aqueous extracts, and larval mortality was monitored after 12, 24, and 48 hours. Three trials were carried out under the same conditions. The percentage mortality of larvae in the sample was calculated, and the mean mortality was obtained for the 3 trials. Then the LC50 value was calculated according to the mean mortality with the SPSS package. The lowest LC50 values were obtained for the hot aqueous extracts on 1st instar larvae: root 122.74 mg/l, leaf 274.95 mg/l and stem 275.92 mg/l, 3rd instar larvae: root 129.37 mg/l, leaf 205.74 mg/l and stem 286.21 mg/l, 4th instar larvae: root 165.52 mg/l, leaf 216.89 mg/l and stem 329.94 mg/l and the root was found to have the highest larvicide activity. Finally, it was identified that by using 165.52 mg/l all three larval instar stages could be killed up to 50% and 90% with 280.921 mg/l. The present study reports that Plumbago zeylanica could serve as a potential larvicidal agent.