Design, Synthesis, and Insecticidal Activity of Novel Isoxazoline Compounds That Contain Meta -diamides against Fall Armyworm ( Spodoptera frugiperda ).

Fall armyworm () is a major migratory pest around the entire world that causes severe damage to agriculture. We designed and synthesized a series of novel isoxazoline derivatives based on the previously discovered active compound to find new and effective candidates against . Most of them showed excellent insecticidal activity. In addition, a three-dimensional quantitative structure-activity relationship model was established, and compound was designed and synthesized based on the results. The bioassay result showed that compound exhibited excellent activity against (LC = 3.46 mg/L), which was substantially better than that of the positive control fipronil (LC = 78.8 mg/L). Furthermore, an insect γ-aminobutyric acid (GABA) enzyme-linked immunosorbent assay indicated that can upregulate the content of GABA in insects in a manner similar to that of fipronil. Molecular docking showed that the hydrophobic effect and hydrogen-bond interactions are vital factors between the binding of and receptors. All of these results suggest that compound could be employed as a novel isoxazoline lead compound to control .