Development of Metal-Organic Framework-Based Emamectin Benzoate Nanopesticides for Effective Control of .

Pine wilt disease is caused by invasion and has a great impact on global pine resources. Injection of emamectin benzoate (EB) into pine trunks is an effective way to control . However, EB has limited aqueous solubility, easily photodissociates, and its long-term use causes resistance problems. In this study, the metal-organic framework material ZIF-8 was prepared, and EB was loaded onto ZIF-8 through physical adsorption, resulting in a pH-responsive EB@ZIF-8 nanopesticide with a high drug loading rate (36.04%). Simulated release experiments of EB@ZIF-8 under different pH conditions showed a cumulative release of 64.43% within 10 h at pH 5.0, which increased as the pH decreased, compared to conditions at pH 7.0 and 9.0. EB@ZIF-8 showed positive insecticidal activity in a laboratory biological test (LC = 52.503 mg/L). In addition, 7 days after trunk injection in , EB residuals were detected in all parts of the branches, with the lowest residue level being 73.39 mg/kg. The proportion of the EB residue in the lower, middle, and upper branches of gradually increased, reaching 43.92% at 28 days after trunk injection, indicating that EB was distributed evenly in the tree. Therefore, EB@ZIF-8 had good morphology, structure, and pH-responsive release performance. EB@ZIF-8 also exhibited a high nematocidal ability due to its smaller particle size and rapid transport in . This study provides a new approach for the development of highly effective EB preparations, improvement of pesticide utilization, and control.