Fungal-mediated nano silver: an effective adulticide against mosquito

Fungi as such are known to be an effective mosquito control agent. In the present investigation, the effect of silver nanoparticles synthesized with Chrysosporium keratinophilum, Verticillium lecanii, and Fusarium oxysporum f.sp. pisi has been evaluated against the adult mosquito of filariasis vector Culex quinquefasciatus. The silver nanoparticles were characterized by using the UV-Vis spectrophotometer and X-ray diffraction techniques. The micrographs of silver nanoparticles were obtained by transmission electron microscope and scanning electron microscope. Elemental analysis on single particle was carried out by EDX analysis. The characterization study confirmed different shapes and sizes of silver nanoparticles. The efficacy test was performed at five different concentrations for a period of 24 h by the probit analysis. The C. quinquefasciatus has shown higher efficacy against the silver nanoparticles synthesized with C. keratinophilum and V. lecanii (lethal concentration (LC)(50) 0.19 and 0.4 mu l/cm(2); LC90 2.4 and 3.2 mu l/cm(2); and LC99 4.0 and 5.6 mu l/cm(2)) after 22 h of exposure. While the silver nanoparticles synthesized with F. oxysporum f.sp. pisi were found to be less effective against the C. quinquefasciatus, the silver nanoparticles synthesized by C. keratinophilum and V. lecanii were found to be more effective than those generated with the help of F. oxysporum f.sp. pisi and C. quinquefasciatus. The use of fungus-mediated silver nanoparticles is a rapid, environmentally safer, and greener approach for vector control strategy and is adaptable globally.