Energy mobilization in Asian ladybug under extreme flight stimulation: Sexual differences in behaviour and metabolism

Harmonia axyridis Pallas is an important predatory insect in biological control. Understanding the relationship between the flight performance and energy metabolism of H. axyridis can optimize its field release strategies and enhance the efficiency of biological control. This study analysed the differences in flight ability, energy metabolic substances and the expression of genes related to these traits under different flight durations between male and female individuals of native H. axyridis using tethered flight assays. Results showed that the pre‐flight body weight, reserves of triglycerides and three types of carbohydrates in female individuals were significantly higher than those in males. The long‐duration and long‐distance flight ability of females was also superior to that of males. In addition, based on gene expression results, it was inferred that in terms of energy metabolism, females primarily consumed glycogen and trehalose for energy during the early flight phase and compensated with minor triglyceride mobilization in the later phase. In contrast, males enhanced trehalose levels through glycolipid conversion to maintain energy supply during the mid‐to‐late flight phases. At the same time, two trehalase activities and related gene expressions indicated that males may primarily rely on increasing soluble trehalase activity to promote trehalose decomposition, while females may mainly depend on membrane‐bound trehalase. In summary, our results indicate that the flight energy metabolism of H. axyridis may follow a ‘carbohydrate‐first, lipid‐subsequent’ pattern. Females performed better in long‐duration and long‐distance flights due to higher initial energy reserves, while males narrowed the later gap through lipid metabolism mobilization. The study not only fills the research gap in the coupling mechanism between flight and metabolism of the H. axyridis but also provides an important theoretical basis for its application and strategy optimization in biological control.