With the evolution of material science, researchers are deeply concerned about the utility of sustainable resources for multifaceted advanced applications. Here we project an abundant, nonedible bioresource-based carbon dot–silver nanohybrid as a highly competent larvicidal agent against Culex quinquefasciatus. Mosquitoes have been the closest enemy of humankind for a very long time. Tropical areas around the globe suffer severe ailments due to mosquito-vector-borne diseases. Japanese encephalitis, lymphatic filariasis, etc. are such fatal threats spread by Culex species. With the emergence of nanotechnology, the perspectives of conventional antivector materials have changed dramatically. The C-dot precursor used here was the roots of Cyperus rotundus, a very abundant grass species found in South Asian countries. The nanohybrid was synthesized by a simple thermal approach without the application of additional reducing agent. The nanohybrid was distributed within a narrow size window of <10 nm. The materia...