Spiny bollworm, Earias insulana causes drastic damages in cotton crop. A new safe strategy rather than insecticide is urgent for its control. Copper nanoparticles (CuNPs) and gelatin-copper nanoparticles (G-CuNPs) were biosynthesized safely using fungal filtrates of Aspergillus wentii, Aspergillus mottae and enecillium expansum. The biosynthesized nanoparticles were confirmed by UV–visible spectroscopy, Transmission electron microscope, Dynamic Light Scattering and Fourier Transform Infrared. G-CuNPs were smaller in size and had strong inhibitory activity against E. insulana than CuNPs at all experimental conditions. The treatment with G-CuNPs synthesized by A. wentii released lowest values of LC50 and LC90 and caused the highest value of larval and pupal mortality, pupal mortality and pupation of the insect. There was highly significant decrease in the percentage of hatchability and egg numbers in the case of treatment with all types of experimental nanoparticles, where G-CuNPs was the best at all. G-CuNPs can be used safely in a management program against Earias insulana.