First synergistic application of nanocarrier-loaded metaflumizone and parasitic wasps: A high-efficiency green pest control strategy.

The improper use of chemical pesticides threatens ecosystems and human health, highlighting the need for sustainable alternatives. Nano-pesticides and biological control agents offer a solution, and their combination can reduce pesticide usage and improve pest control efficacy. This study utilized a star polycation (SPc) to prepare a metaflumizone nano-pesticide and combined it with the egg parasitoid (Telenomus remus) for synergistic pest management. SPc exhibited minimal toxicity to T. remus at working concentrations but caused mortality at extremely high doses, with an oral LC50 of 4.23 mg/mL. RNA-seq analysis revealed that the stress responses in T. remus induced by SPc included enhanced phagocytosis, exocytosis and energy synthesis. The SPc self-assembled with metaflumizone through hydrogen bonding and Van der Waals forces, reduced the particle size to the nanoscale (467.25 nm). The nano-pesticide increased stomach toxicity against Spodoptera litura by over 30 %, which showed no significant toxicity to T. remus eggs or adults and maintained parasitic capacity. The combined application of metaflumizone/SPc complex and T. remus achieved over 90 % pest control efficacy, providing a novel and effective strategy for sustainable pest management.