Sustainable pest management: synergistic mechanisms of mesoporous silica‐mediated Bacillus thuringiensis delivery in Plutella xylostella control

Background Bacillus thuringiensis (Bt) has emerged as a promising biopesticide globally due to its target specificity, environmental safety, biodegradability, and lack of residual toxicity and a low likelihood of inducing insect resistance. However, its practical application faces critical limitations due to UV sensitivity and short‐field persistence, constraining broader commercial development. Results This study developed mesoporous silica nanoparticles (MSN) as nanocarriers for Bt biopesticides, synthesizing MSN‐Bt composites with a high specific surface area (333.08 m 2 /g). The binding process of the two is mainly dominated by hydrogen bonds, and hydrophobic interaction is synergistic. Compared to raw Bt powder, MSN‐Bt significantly enhanced insecticidal efficacy against Plutella xylostella (diamondback moth), offering UV protection and reduced degradation to maintain bioactivity and stability. Anti‐washing experiments show that its wettability, adhesion and rain washing resistance are improved. At the same time, the highest cumulative release rate can reach 97.12% under alkaline conditions. MSN‐Bt further induced reactive oxygen species (ROS) production in the insect midgut, exacerbating damage to epithelial cells and microvilli, thereby accelerating disruption of the digestive system. Bioassays confirmed that MSN‐Bt effectively minimized cabbage leaf damage caused by P. xylostella , whereas pure MSN showed no pesticidal activity. Moreover, MSN and the composites did not significantly affect the non‐target organisms. Conclusion MSN can serve as eco‐friendly and efficient carriers for biological pesticides, offering a novel strategy for the stable delivery of Bt and enhancing its practical application in sustainable agriculture.