Next-gen nanoformulations for insect growth regulation: Reducing environmental load with targeted lufenuron delivery

The growing demand for sustainable pest control necessitates advanced delivery systems that enhance insecticidal efficacy while minimizing environmental impact. In this study, we developed and evaluated polycaprolactone (PCL)-based nanoparticles for encapsulating lufenuron, an insect growth regulator, with the primary aim of developing and characterizing the nanoformulation and the secondary aim of assessing its potential efficacy against Rachiplusia nu relative to conventional formulations. The nanoparticles were synthesized via nanoprecipitation and characterized by particle size (264 ± 5 nm), zeta potential (–44 ± 1.2 mV), encapsulation efficiency (>99 %), and surface morphology, with atomic force microscopy confirming uniform spherical structures. Stability studies over 90 days showed negligible size and surface charge variation, ensuring formulation robustness under storage conditions. In vitro release assays revealed an erosion-controlled release profile, with the nanoencapsulated formulation releasing the active compound up to eight times more slowly than free lufenuron. Biological performance was validated through in vitro (artificial diet) and in vivo (semi-field) assays conducted in duplicate trials. The nanoformulated (NP_PCL_LFN) and commercial lufenuron (LFN) achieved nearly 100 % larval mortality at the highest tested concentrations. NP_PCL_LFN maintained effective control at a reduced application rate, showing equivalence to the commercial formulation under low-concentration conditions. In semi-field trials, both treatments provided > 76 % control at full dose, with nanoencapsulation sustaining comparable efficacy at lower levels. These results underscore the potential of PCL-based nanoformulations to enhance pesticide stability, control release kinetics, and reduce application rates, offering a promising route for precision agriculture and resistance management in integrated pest control strategies.