Standardized Synergistic Strategy for Insect Growth Regulators: Incorporation of RNA Pesticides via a Co-Delivery Nanoplatform Achieves High Control Efficacy with Low-Dosage Application

Insect growth regulators (IGRs) face limitations of slow action and high dosage, while RNA pesticides are constrained by the scarcity of effective RNAi targets. Here, we propose a standardized strategy to develop multicomponent nanopesticides by combining IGRs with RNA pesticides via a co-delivery nanoplatform. The star polycation (SPc) nanocarriers and diflubenzuron (DFB) were assembled into nanoscale DFB/SPc complexes, enhancing toxicity against green peach aphids by disrupting chitin biosynthesis. RNA-seq analysis identified chitin synthase (CHS) as a synergistic RNAi target. The hpCHS/SPc complex effectively silenced CHS, inducing more than 50% aphid mortality. Co-loading dsCHS and DFB produced stable nanoparticles with improved leaf adhesion, plant uptake, aphid cuticle contact, and translocation, achieving up to 82.2% mortality at only LC20 of free DFB. This work establishes a generalizable, scalable approach for designing multicomponent nanopesticides with high efficacy and low dosage for sustainable pest control.