Bio-Efficacy of Green Synthesized Silver Nanoparticles and Methanolic Leaf Extracts of Zanthoxylum armatum on Megaselia halterata

Megaselia halterata (Diptera: Phoridae), commonly referred to as the scuttle fly is cosmopolitan insect pest posing a significant threat to agriculture as it can infest wide range of crops particularly Agaricus bisporus, causing 30–70% yield losses. The current research explores the potential use of biosynthesized silver nanoparticles from Zanthoxylum armatum (ZA-AgONPs) against M. halterata on Agaricus bisporus. The biosynthesis of AgONPs was confirmed through various characterization techniques, i.e., UV-visible spectroscopy, X-ray diffraction, Fourier-transform infrared spectroscopy, scanning electron microscopy and transmission electron microscopy. In vivo experiments demonstrated the efficacy of ZA-AgONPs in reducing the adult emergence of M. halterata and minimizing sporophore damage to A. bisporus. The highest reduction in adult emergence (94%) and the least sporophore damage (3.92–4.16%) were achieved at 50 ppm concentration. Additionally, the highest mushroom production (4.92 kg/bag) was recorded at 50 ppm of ZA-AgONPs, surpassing both the methanolic extract application (4.57 kg/bag) and control treatments. Furthermore, in vitro experiments revealed a concentration and time dependent increase in the mortality of M. halterata larvae. The highest mortality rate (98.33%) was observed at 50 ppm after 48 h. The green-synthesized ZA-AgONPs showed greater efficacy as compared to methanolic leaf extract as evident by lower LC50 and LC90 values. These findings suggest that Z. armatum-derived AgONPs presents a promising biocontrol solution for sustainable mushroom cultivation and pest management.