Tannic-Acid-Modified Mesoporous Silica Nanocarriers Enhance Chlorantraniliprole Delivery against Hyphantria cunea by Improving Foliar Adhesion

Abstract

The fall webworm Hyphantria cunea (Lepidoptera: Erebidae) is an invasive pest that severely damages forest resources and disrupts ecological stability. Chlorantraniliprole (CAP) is widely applied to control this pest, yet conventional formulations exhibit poor foliar retention, droplet spreading, and rainfastness. To address these limitations, we prepared tannic acid (TA)-modified mesoporous silica nanoparticles (MSN) loaded with CAP (TA@CAP@MSN) to enhance insecticidal efficacy and foliar adhesion. TA@CAP@MSN were uniform mesoporous nanospheres with 162.95 m2/g specific surface area, 0.241 cm3/g pore volume, 27.83% drug loading, and sustained-release performance. After 72 h of exposure, the LC50 of TA@CAP@MSN against third-instar H. cunea was 2.130 mg/L, corresponding to a 3.66-fold increase in toxicity relative to technical CAP. When sprayed on Populus × euramericana leaves, this nanoformulation achieved 62.33% larval mortality at 120 h. Notably, TA@CAP@MSN exhibited superior retention, wettability, and rainfastness on three representative host plants with distinct leaf surface properties. After simulated rainfall, mortalities under LC50/LC80 were significantly higher than those of pure CAP and CAP@MSN. Sublethal studies revealed that TA@CAP@MSN initially modulated key detoxification and antioxidant enzymes, followed by suppression of superoxide dismutase (SOD) and carboxylesterase (CarE) activities, consistent with altered antioxidant and detoxification responses. This tannic-acid-functionalized mesoporous silica nanocarrier provides an interfacial engineering strategy to construct high-efficiency nanopesticides against H. cunea.