Dual oxidase is essential for moulting, hatching and feeding in the brown planthopper

Dual oxidase (Duox) is well-known for its role in immunity and tyrosine cross-linking activity across various biological processes from mammals to holometabolous insects. Nevertheless, its function in hemimetabolous insects remains poorly understood. In this study, we explored the physiological roles of the Duox gene in a hemimetabolous insect, the brown planthopper, one of the most devastating rice pests. A comprehensive analysis of the spatiotemporal expression pattern of the Duox gene was conducted. RNA interference (RNAi)-mediated silencing of the Duox gene led to moulting defects in nymphs, wing abnormalities and impaired feeding in adults and reduced hatchability in eggs. Additionally, Duox knockdown significantly reduced hydrogen peroxide (H₂O₂) levels in premoulting nymphs and female ovaries. These findings highlight the indispensable role of Duox in moulting, hatching, wing expansion and feeding behaviours in the brown planthopper, shedding light on the relationship between H₂O₂ production and cuticle structural stability.