Development of bioformulations using plant extracts for the control of dengue vector, Aedes aegypti

Abstract

Dengue fever is a life-threatening illness in humans caused by the dengue virus belonging to Flaviviridae, affecting mainly in tropical and subtropical countries. The spread of this disease is through the dengue vector Aedes aegypti. Development of biodegradable, environmentally safe, low-cost larvicides is essential to overcome the resurgence effects of chemical insecticides. The present study included the development of bioformulations from larvicidal polar solvent extracts of the plant leaves. The solvents used for the extractions were ethyl acetate for Aloe vera (A), ethanol for Carica papaya (B), and methanol for Parthenium hysterophorous (C). Bioformulations in different combinations like A, B, C, A+B, B+C, C+A, and A+B+C with the concentrations of 50ppm, 100ppm, 150ppm, 200ppm, 250ppm and 300ppm were tested against the IVth instar larvae of Aedes aegypti and the results were recorded for every 24h 48h and 72h . The bioformulation extracts B+C (300ppm) showed 90 percent mortality of larvae after 72 h of treatment. It was concluded that the larvae's mortality was caused by the presence of bioactive compounds of B+C extracts. This formulation can be considered an effective biopesticide for the dengue vector Ae. aegypti IVth instar larvae.