The effect of green synthesis of silver nanoparticles using Dodonaea viscosa plant extract against mealybugs Phenacoccus solenopsis Tinsley (Hemiptera: Pseudococcidae) as a biocontrol agent

The control of Phenacoccus solenopsis Tinsley (Hemiptera: Pseudococcidae) has traditionally relied on synthetic insecticides that pose significant environmental and health risks, including the development of insecticide resistance. To offer a safer and more sustainable alternative, this study investigated the use of silver nanoparticles (AgNPs) synthesized via a green approach using aqueous extracts of Dodonaea viscosa. The insecticidal efficacy of D. viscosa extract at concentrations of 25%, 50%, 75%, and 100%, along with AgNPs synthesized from the same extract, was assessed against P. solenopsis. Phytochemical profiling of D. viscosa was conducted using GC-MS, and AgNP formation was confirmed through color change, FTIR spectroscopy, AFM, SEM, and EDX analyses. The highest mortality rate from the aqueous extract alone was 18.0% after 9 days at 100% concentration, whereas treatment with 1 mM and 0.5 mM AgNPs (at 50% extract concentration) resulted in mortality rates of 51.0% and 52.22%, respectively. These findings demonstrate the enhanced insecticidal potential of AgNPs compared to crude plant extracts, supporting their use as more effective and environmentally friendly biocontrol agents. This study is among the first to compare the efficacy of D. viscosa-based AgNPs against mealybugs, highlighting their potential as novel tools for sustainable pest control. However, further field trials are required to evaluate their practical applicability.