Nanodelivery Improves Insecticidal Activity of Hexaflumuron against <i>Apolygus lucorum</i> by Inhibiting the Synthesis of Insect Cuticle Protein

Given the limitations of conventional pesticides, sustainable pest control alternatives are urgently needed. Hexaflumuron (HE), an insect growth regulator, is a potential candidate, yet its efficacy requires enhancement. This study developed a star polycation (SPc)-based nanocarrier to improve HE delivery. The HE/SPc complex was formed via electrostatic and van der Waals interactions, reducing the particle size from 751.21 to 174.62 nm. Compared to HE alone, HE/SPc complex enhanced retention and coverage for effective foliar application, and significantly enhanced insecticidal activity against <i>Apolygus lucorum</i> nymphs. It prolonged nymphal development, increased mortality, and reduced the body weight. Mechanistically, HE/SPc down-regulated cuticle-related genes, impairing cuticle formation and elevated detoxification enzyme activities (CYP450, CarE, GSTs). Additionally, SPc reduced the HE phytotoxicity in bean seeds. This work established a promising SPc-based delivery platform for insect growth regulators and offered a design strategy for novel and efficient pesticide formulations.