Phytofabrication of Silver Nanoparticles from Water Hyacinth (Eichhornia crassipes) as a Potential Pest Control Tool for Spodoptera frugiperda 

The invasive fall armyworm (Spodoptera frugiperda) threatens Philippine crops, highlighting the need for sustainable pest management. This study therefore optimizes the green synthesis of silver nanoparticles (AgNPs) from water hyacinth (Eichhornia crassipes), an abundant and problematic aquatic weed, as a potential pest control tool. Methanolic leaf extracts were prepared under varying methanol concentrations, temperatures, and extraction times, and total phenolic content was quantified using the Folin–Ciocalteu method. SEM–EDX confirmed the formation of silver nanoparticles synthesized from Eichhornia crassipes (Ec-AgNPs), with particles observed at ≤100 nm. Optimal extraction occurred at 47 °C, 90% methanol, and 76 min, maximizing phenolic yield. Overall, results suggest phenolic content and extract volume influence nanoparticle size and stability, with larger extract volumes increasing agglomeration risk. Pesticidal efficacy was not evaluated; further work is needed to assess pest control performance.