Abstract
Forests, which cover approximately 30% of the Earth’s land surface, are increasingly threatened by pests such as Odontotermes obesus , causing significant economic and ecological damage. The present study investigated the biosynthesis of silver nanoparticles (AgNPs) using Azadirachta indica (neem) leaf extract and evaluated their insecticidal efficacy against O. obesus. AgNPs were synthesized via a green approach and characterized using UV–Vis spectroscopy (peak at 419 nm), FTIR (functional groups confirming phytochemical involvement), XRD (face-centered cubic structure with a crystallite size of 14 nm), and SEM (spherical morphology with an average size of ~ 5 nm). Bioassays, including a filter paper choice repellency assay, contact-toxicity mortality assay, and behavioral tunneling and antifeedant assessments, were conducted using 20 termites per replicate with three replicates for each treatment. The synthesized AgNPs exhibited strong bioactivity, repelling 93.3 ± 2.35% of termites and causing 100% mortality at concentrations of 25 mg/L, 20 mg/L, and 15 mg/L within 50, 60, and 70 min, respectively. Lower concentrations (10 mg/L and 5 mg/L) resulted in mortality rates of 53.09% and 47.19%, respectively. Statistical analysis indicated significant effects of both concentration and exposure time on termite mortality ( p ≤ 0.05). Furthermore, AgNPs disrupted tunneling behavior and reduced feeding activity, with an antifeedant index of 78.1 ± 2.66%.These findings demonstrate that neem-derived AgNPs are a promising alternative bioinsecticidal agent for integrated forest pest management, offering effective repellency, rapid toxicity, and behavioral disruption.