Application of bio-based nanopesticides for pine surface retention and penetration, enabling effective control of pine wood nematodes

The Pine wood nematode disease is a significant biological threat to forestry management and ecological restoration worldwide, with chemical control remaining the primary approach. However, the cryptic nature of pine wood nematodes (PWN) limits the effectiveness of conventional pesticides. This study explores the development of a cellulose network carrier-based nanopesticide (Se@CSM/PDA@AZO-CNF) loaded with selenium nanoparticles, offering dual responsiveness to light and temperature. This innovative design enables the precise release of pesticides under natural conditions, supporting a controlled response. Incorporating selenium nano- particles into the cellulose-based nanopesticide improved pesticide permeability and deposition in pine trees. The contact angle of pesticides on pine needles decreased by 23 degrees, their resistance to washing increased by 39 %, and cumulative release was significantly enhanced under UV light and low temperatures. Fluorescence tracer experiments demonstrated efficient uptake of Se@CSM/PDA@AZO-CNF nanopesticide by PWN. The hydrogel displayed an LC50 value of 29.1 mg/L against PWN. These findings highlight the potential of this nanopesticide to improve pesticide delivery and efficacy in controlling pine wood nematode disease.