Exposure to Sublethal Concentrations of Dinotefuran Induces Apoptosis in the Gut of <i>Diaphorina citri</i> Adults via Activating the Mitochondrial Apoptotic Pathway

<i>Diaphorina citri</i> is a serious citrus pest. Dinotefuran is highly insecticidal against <i>D. citri</i>. To analyze the sublethal effects of dinotefuran on <i>D. citri</i> adults, an indoor toxicity test was performed, which revealed that the lethal concentration 50 (LC₅₀) values were 4.23 and 0.50 μg/mL for 24 and 48 h treatments, respectively. RNA-Seq led to the identification of 71 and 231 differentially expressed genes (DEGs) after dinotefuran treatments with LC₂₀ and LC₅₀ doses, respectively. Many of the DEGs are significantly enriched in the apoptosis pathway. Dinotefuran-induced apoptosis in the gut cells was confirmed through independent assays of 4',6-diamidino-2-phenylindole (DAPI) and TdT-mediated dUTP nick end labeling (TUNEL) staining. Increased levels of reactive oxygen species (ROS) and a loss of mitochondrial membrane potential were observed. Four caspase genes were identified, and dinotefuran treatments resulted in increased mRNA levels of <i>DcCasp1</i> and <i>DcCasp3a</i>. These findings shed light on the sublethal effects of dinotefuran on <i>D. citri</i>.