Phytofabrication of silver nanoparticles using Elephantopus scaber and Azadirachta indica leaf extract and its effect on larval and pupal mortality of Culex quinquefasciatus

Objective: To synthesize silver nanoparticles by using Azadirachta indica (A. indica) and\udElephantopus scaber (E. scaber) leaf extract as reducing and stabilizing agent and to check the\udefficacy of silver nanoparticles towards mortality of mosquito larval and pupal stages of Culex\udquinquefasciatus (Cx. quinquefasciatus).\udMethods: The silver nanoparticles were synthesized using A. indica and E. scaber leaf extract.\udThe synthesized nanomaterials were characterized using UV-vis spectrophotometer, Fourier\udtransform infrared spectroscopy, transmission electron microscopy and fluorescent microscopy.\udFinally, the synthesized nanoparticles were applied on fourth instar larval and pupal stages of\udCx. quinquefasciatus larvae and pupae and mortality was counted for 48 h. Dead larval bodies\udwere electron dispersive X-ray studied to see whether silver has entered into the body or not.\udPupal hatching under the influence of these nanoparticles were also studied.\udResults: Silver nanoparticles were synthesized from A. indica and E. scaber leaf which were\udstable. Mortality results highlighted that LC50 and LC90 of A. indica and E. scaber induced\udsilver nanoparticle are 1.64, 4.32 mg/L and 1.43, 4.32 mg/L respectively during 48 h of\udincubation. EDX study of dead larval body showed a clear signature of silver in their body\udwhich suppose to be the main cause of their mortality. Pupal hatching is also hampered by the\udsublethal doses.\udConclusions: A. indica and E. scaber may be good source as reducing agent of stable silver\udnanoparticles. Green synthesized silver nanoparticles may be a good eco-friendly alternative to\udcontrol mosquito larvae and pupae of Cx. quinquefasciatus