Ovicidal and adulticidal activity of nerium oleander extract against anopheles stephensi liston (insecta: diptera: culicidae)

Roni, M., Murugan, K., Christina Mary, S., Sivapriyajothi, S., Suganya, N.A, Dinesh, D., Vivek, S

Objective: To test the smoke toxicity effect of Nerium oleander on biting activity and ensured population of Anopheles stephensi and to prepare different solvent extracts of Nerium oleander to determine it’s ovicidal and adulticidal efficacy against Anopheles stephensi.
Methods: In the present study, Nerium oleander leaves, stem and root were collected, washed and shade dried in enamel trays at room temperature. Then the dried plant parts were powdered with an electric blender. From the powder 200g of the plant material were extracted with 2.5 litres of different solvents such as aqueous solution, ethyl acetate and ethanol for 8 hrs in a soxhlet apparatus. The crude plant extracts were evaporated to dryness in rotary vacuum evaporator. One gram of the plant residue was dissolved in 100 ml of acetone (stock solution), considered as 1% stock solution. From this stock solution concentrations were prepared ranging from 100 to 300 ppm. The extract was tested for its ovicidal and adulticidal activity, and mosquito coil was prepared using different plant parts and its smoke toxicity was noted against the malaria vector under laboratory conditions.
Results: Ovicidal and adulticidal activity was measured by preparing different concentrations of different solvent extracts of N.oleander. Smoke toxicity effect of the plant by preparing Mosquito coil from different parts of N.oleander powder. The mortality rates of crude using solvent extract at 300ppm were higher than all other concentrations when tested against the adult mosquitoes at 24h-48h of exposure. Smoke exposed females have produced fewer eggs when compared to the non-exposed female An.stephensi mosquitoes.
Conclusions:The results indicate promising ovicidal and adulticidal activity against Anopheles stephensi. The plant parts and solvent used for extraction, phototoxic activity and the geographical origin of the plant compound are important factors in the efficacy of a phytochemical and the results showed that the mosquitocidal mortality was dose dependent. The use of plant N. oleander as a biological insecticide is a rapid, environmentally safer, and greener approach for mosquito control.