STM Article Repository

Mosquitoes are vectors of several diseases of public health importance. Their control with synthetic insecticides has faced challenges of resistance by target insects and consequent environmental pollution. There is therefore need to find alternative ecofriendly plant derived insecticide. Therefore toxicity activities of Jatropha curcas seed extract against the 4th instar larvae and pupal stages of Aedes aegypti was studied in vitro with increasing doses of Jatropha curcas seed extract for 96 hours. The result showed significant difference between mortality among treated animal and control (P< 0.05). Mortality of both larvae and pupae of Aedes aegypti treated with Jatropha curcas seed extract was dose and time dependent. At the highest (9%) concentration (wt/vol), mean larval mortality was 100%, while at the lowest (1%) concentration, the mortality decreased to 50%. Mean pupal mortality increased to 100% at highest concentration of 9% (g/100ml) but decreased to 40% at lowest concentration. The duration of incubation also influenced mortality. At 72 and 96 hours of incubation all treated larva died in highest concentrations of the extract (9% and 7%) while the entire treated pupa died out in 96 hours of incubation at the highest concentration (9%) of the extract. Survived larva and pupa after 96 hours in lower concentration could not develop to adult stage. In conclusion Jatropha curcas seed water extract has toxicity effects on larvae and pupae of Aedes aegypti and can be deployed for the control of the insect.