Toxicity of luteolin on Hyphantria cunea larvae: construction of plant‐derived microcapsule pesticide

BACKGROUND Hyphantria cunea , a major global quarantine pest, poses significant threats to agroforestry ecosystems and sustainable economic development. This study investigated the formulation of luteolin microcapsules via a single coacervation method, based on biotoxicity analysis of luteolin against H. cunea larvae. RESULTS Luteolin effectively induced toxic effects on H. cunea larvae, including reduced body weight and survival rate, as well as the disruption of growth‐regulatory genes (e.g. FOSL1 , BIRC6 and MYC ). Notably, marked activation of the detoxification enzyme system [e.g. glutathione S ‐transferase (GST) and carboxylesterase CarE)] and antioxidant system [e.g. superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD)] was observed in luteolin‐treated H. cunea larvae. However, luteolin treatment still disrupted physiological homeostasis through a dual pathway: (i) inducing oxidative stress, evidenced by elevated levels of malondialdehyde and hydrogen peroxide; and (ii) inhibiting glycolysis and the tricarboxylic acid cycle, leading to the depletion of glucose, free fatty acids and other essential nutrients. The luteolin microcapsules demonstrated favorable sustained‐release properties, thermal stability and resistance to photolysis. Furthermore, they exhibited lower toxicity to non‐target organisms, such as Danio rerio and Arma chinensis nymphs, indicating their environmental safety. Both laboratory and field bioassays confirmed that the luteolin microcapsules displayed similar growth toxicity and lethal effects on H. cunea larvae, with insecticidal activity surpassing that of the unencapsulated luteolin. CONCLUSION This study for the first time identified the core insecticidal mechanism of luteolin as a plant‐derived insecticide, with the developed microcapsules offering an efficient, eco‐friendly and safe solution for controlling H. cunea larvae.