Gamma-Irradiation Assisted Silver Nanoparticles Synthesis Using Silybum marianum Leaf Extract, Its Characterization and Toxic Effect Against the Larvae of Cotton Leaf Worm, Spodoptera littoralis (Lepidoptera: Noctuidae)

We examined the potential of Silybum marianum leaf extract as a “green” stabilizing and capping agent integrated with gamma irradiation for the synthesis of spherical silver nanoparticles (Ag NPs). Synthesized Ag NPs were characterized by transmission electron microscopy (TEM), dynamic light scattering (DLS) and X-ray diffraction analysis (XRD). Characterization revealed stable spherical particles with an average size 8.2 nm for the synthesized Ag NPs at 40 KGy. Gamma irradiation played a significant role in increasing the yield of Ag NPs and decreasing their size. The larvicidal activity of the fabricated Ag NPs was evaluated against the third instar larvae of Spodoptera littoralis. Observed results revealed that LC50 and LC90 of the synthesized Ag NPs were 170.76 and 818.81mg/L, respectively. Overall, the results highlighted the important role of gamma irradiation integrated with plant extract in synthesis and stabilization of Ag NPs and their insecticidal efficacy against S. littoralis larvae.