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<i>Chitin synthase 1</i> (<i>CHS1</i>) is an essential gene regulating chitin during different developmental stages of arthropods. In the current study, we explored for the first time the role of <i>CHS1</i> gene regulation in the citrus red mite, <i>Panonychus citri</i> (McGregor) (Acari: Tetranychidae), by silencing its expression using (RNA interference) RNAi-based strategies. The results reveal that <i>P. citri</i> tested in different developmental stages, including larvae, protonymphs, deutonymphs, and adults fed on sweet orange leaves dipped in various concentrations (200, 400, 600, and 800 ng/μL) of dsRNA-<i>PcCHS1</i>, resulted in a continuous reduction in their gene expression, and the extent of transcript knockdown was positively correlated with the concentration of dsRNA. Concentration–mortality response assays revealed a mortality of more than 50% among all the studied developmental stages, except for adulthood. Furthermore, the target gene dsRNA-<i>PcCHS1</i> treatment of larvae, protonymphs, deutonymphs, and females at a treatment rate of 800 ng/mL of dsRNA significantly decreased the egg-laying rates by 48.50%, 43.79%, 54%, and 39%, respectively, and the hatching rates were also considerably reduced by 64.70%, 70%, 64%, and 52.90%, respectively. Moreover, using the leaf dip method, we found that the RNA interference effectively reduced the <i>PcCHS1</i> transcript levels by 42.50% and 42.06% in the eggs and adults, respectively. The results of this study demonstrate that the RNAi of <i>PcCHS1</i> can dramatically reduce the survival and fecundity of <i>P. citri</i>, but the dsRNA concentrations and developmental stages can significantly influence the RNAi effects. These findings indicate the potential utility of the <i>PcCHS1</i> gene in causing developmental irregularities, which could aid in the development of effective and novel RNAi-based strategies for controlling <i>P. citri</i>.