Innovative Biopesticides: Nanoformulation of  Mentha Piperita L. and Satureja Montana L. Essential Oils for Controlling the Cotton Bollworm, Helicoverpa armigera Hub.

Helicoverpa armigera Hubner, a major agricultural pest, is traditionally controlled by chemical insecticides, which pose environmental and health risks. Eco‐friendly alternatives, such as plant essential oils, are promising but face challenges like volatility and rapid oxidation. Nanoencapsulation offers a novel solution to enhance their stability and efficacy. This study aims to evaluate the insecticidal effects of chitosan (CS) nanocapsules loaded with Mentha piperita L. (M.EO@NPs) and Satureja montana L. (S.EO@NPs) essential oils (EOs) against H. armigera . Bioassay experiments were conducted on third instar larvae using the fumigation method. After 48 h of exposure, the LC 50 values for Mentha piperita essential oil (M.EO) and Satureja montana essential oil (S.EO) were 185 and 30 µL/L air, respectively, while for the nanoencapsulated forms, the LC 50 values were 296 and 44.2 µL/L air, respectively. Sublethal effects were assessed by exposing larvae to the LC 30 concentration of each EOs and EO@NPs. The LC 30 of both EOs and EO@NPs caused adverse effects on the biological parameters of surviving insects. The loaded nanoparticles exhibited a spherical shape, with average particle sizes of 45.5 nm (PDI = 0.544) for M.EO@NPs and 102 nm (PDI = 0.944) for S.EO@NPs. Fumigation toxicity studies of the nanoformulated essential oils demonstrated a slow and persistent release of the active ingredients from the nanomaterials, highlighting the effectiveness of CS nanoencapsulation in prolonging the insecticidal effect. These nanoencapsulated essential oils, with their high biological activity and insecticidal properties, offer an alternative strategy for protecting greenhouse plants against H. armigera and show great potential as part of an integrated pest management (IPM) approach.