Green Synthesis of Silver and Copper Nanoparticles for Potential Biopesticide Application Against Oriental Fruit Fly (Bactrocera dorsalis Hendel)

Abstract

Background: The fruit fly species Bactrocera dorsalis (Hendel) is one of the most severe pests affecting most tropical countries' agricultural fruits.The green synthesis of silver and copper nanoparticles from plant extracts is aimed at determining the potential application of nanoparticles against B. dorsalis. Methods: Silver (AgNPs) and copper nanoparticles (CuNPs) were synthesized from reacting AgNO3 and CuSO4.5H2O, respectively, with Cymbopogon citratus and Tridax procumbens extract.Optimization was done by varying the reaction mixture's volume ratio, pH, and temperature. The percent mortality of fruit flies was evaluated after progressive exposure to AgNPs and CuNPs. Results: The formation of AgNPs and CuNPs using plant extracts is favorable in alkaline conditions-pH 11 (C. citratus) and pH 9 (T. procumbens) extract, requiring 50ºC for AgNPs, and <70ºC for CuNPs. AgNPs and CuNPs in agglomerates have approximate sizes of 70 nm and 57 nm, respectively. T. procumbens-AgNP exhibited the highest anti-fruit fly activity, causing 66.7 ± 23.1% mortality. AgNPs have significantly improved the two plant extracts' insecticidal activity, while CuNPs have caused no mortality. Conclusion: This study further proves the effectiveness of AgNPs in pest control.AgNPs can be incorporated into bait stations using natural attractants to prevent environmental concerns.