Maize is a critical component of global food security; however, pests like the oriental armyworm (Mythimna separata Walker) cause significant yield losses to this crop. Conventional control approaches for managing this insect rely on pesticide applications, which pose environmental risks and can lead to pest resistance. Thus, the necessity for alternative management strategies is emphasized. Silicon (Si) is proposed as a pesticide substitute due to its ability to mitigate a plethora of biotic and abiotic stresses in plants. To evaluate the effectiveness of Si in controlling the armyworm, maize plants were treated with three Si concentrations (T1: 500 mg/L, T2: 750 mg/L, T3: 1000 mg/L) and then infested with armyworm larvae. The performance of the insect pest was assessed by evaluating its larval feeding and oviposition preference, mandibular morphology, survival rates, and weight gain. Results showed a mean larval survival rate of 63% in T3 plants compared to 96% in control. The weight of larvae fed on control leaves was twice that of those fed on Si-treated leaves. Likewise, the incisor length of larvae fed on Si-treated leaves was significantly shorter (177 µm) than those fed on control leaves (447 µm). Moreover, Si-treated leaves were less favorable for egg laying, with only 20% of eggs laid on them. These findings indicate that Si supplementation enhances maize resistance to the infestation of the oriental armyworm. This Si-mediated resistance of maize plants against the oriental armyworm underscores the potential of Si supplementation as a sustainable alternative to chemical pesticides in integrated pest management strategies.

Maize plants (SMC-5 variety) were grown in a greenhouse under a completely randomized design with four silicon (Si) treatments (0, 500, 750, 1000 mg/L). Si accumulation was quantified using a colorimetric assay. Mythimna separata larvae, collected from maize fields, were reared under controlled conditions. No-choice feeding assays measured larval biomass and survival, while dual-choice oviposition assays recorded egg counts. Mandibles of larvae fed Si-treated leaves were imaged using stereo zoom and scanning electron microscopy to assess incisor wear. Antioxidant enzyme activity (SOD, CAT, POX) in maize leaves was determined using phosphate buffer homogenization and spectrophotometry.