This work was to evaluate the efficacies of the nanoparticles (NPs) of silver (Ag) and Gold (Au) against the major tropical mosquitoes. In the present study, the Ag and Au NPs were synthesized by using the cell free extract of Fusarium oxysporum f.sp. pisi fungus. The bioreduction of AgNPs and AuNPs was monitored by ultraviolet-visible spectroscopy, and the AgNPs and AuNPs obtained were characterized by transmission electron microscopy and scanning electron microscopy. The synthesized AgNPs and AuNPs were spherical particles ranging in size from 20-40 nm (AgNPs) and 2-10 nm (AuNPs). Further, these synthesized NPs were also tasted as larvicides and pupicides against the larvae and pupae of Cx. quinquefasciatus, An. stephensi and Ae. aegypti. The efficacy test was performed at different concentrations for a period of different hours by the probit analysis. The maximum efficacy was observed in synthesized AgNPs against the larvae of Ae. aegypti (LC50 8, 6, 4, LC90 12.30, 12.58, 11.48, LC99 15.48, 13.48, 12.88 ppm, respectively for first, second and fourth in stars) after 1 h and pupae (LC50, 2, LC90 11 and LC99 13 ppm) after 2 h. The maximum efficacy was observed in AuNPs against the larvae of Cx. quinquefasciatus (LC50 12.58, LC90 30.00 and LC99 42.65 ppm) after 48 h. This suggest that the synthesized Ag and Au NPs could be an environmentally safer, greener and better approach for mosquito control than current approach.
