Green production of eco-friendly AgNPs and evaluation of larvicidal activity against Cydia pomonella (L.) (Lepidoptera: Tortricidae)

Abstract

Cydia pomonella (L.) is an important apple pest and causes irreversible damage to apples if not controlled. Therefore, different control methods are intensively applied against this lepidopteran pest in apple orchards. Since the larval stage of the pest is very harmful for apples, many studies focus on this life stage and new control techniques are developed every year. After the production of metallic nanoparticles as a new nanotechnological product through green synthesis, it has been proven to be highly effective against the larval stage of many pests in recent years. This study covers the synthesis of silver nanoparticles (AgNPs) from the extract of Windmill palm (Trachycarpus fortunei (Hook.) H. Wendl.) fruits and the efficacy of this synthesised product in larval control of this lepidopteran pest. The morphological and functional structure of the synthesised AgNPs were determined by characterisation tests (UV-Vis, FT-IR, XRD, SEM, TEM, EDS) and it was determined that the synthesised AgNPs were approximately 10-20 nm in size and had high silver ion ratios. The synthesised AgNPs were applied to the 4th stage larvae of the pest by spraying method at 6 different doses (25, 50, 75, 100, 125 and 150 ppm) and larvicidal activity was evaluated in terms of mortality rates depending on the days after application. According to the results obtained, 18% mortality rate was reached at the lowest dose at the end of the 4th day, mortality rate increased as the dose increased and 100% mortality rate was reached at the highest dose. This study proved that the synthesised AgNPs were highly effective against this lepidopteran pest and provided a basis for similar nanotechnological studies in the future.