Evaluation of novel insecticides against fall armyworm (Spodoptera frugiperda) via laboratory bioassay and field experiment findings

Fall armyworm ( Spodoptera frugiperda ) is a major agricultural pest responsible for significant economic losses globally. Due to the rising concerns over the overuse of synthetic insecticides, there is an increasing demand for safer and more sustainable alternatives. This study evaluated the efficacy of various chemical and biorational insecticides: neem (5 mL L⁻¹), timur extract (5 g L⁻¹), Btk + S. spinosa (2 mL L⁻¹), spinosad (0.3 mL L⁻¹), emamectin benzoate + abamectin (0.4 g L⁻¹), and chlorantraniliprole (0.4 mL L⁻¹) against fall armyworm under both laboratory and field conditions, with water spray serving as a control. Laboratory bioassays were conducted using a leaf dip method in a Completely Randomized Design (CRD) with four replications per treatment and 20 larvae per replication (total = 560 larvae). Leaves were dipped in each insecticide solution at recommended concentrations. Complete mortality within 12 h was observed for Btk + S. spinosa, spinosad, and Ema. + Aba., while chlorantraniliprole and neem required 42 and 84 h, respectively. Field trials followed a Randomized Complete Block Design (RCBD) with seven treatments and three replications. Insecticides were applied at specific label-recommended rates at 25, 35, and 45 days after sowing (DAS) when infestation exceeded the economic threshold level. Ema. + Aba., chlorantraniliprole, and spinosad significantly reduced larval population and foliar damage, while enhancing maize growth and yield. These findings suggest that selected insecticides, particularly spinosad, Ema. + Aba., and chlorantraniliprole, are effective and economically viable options for integrated fall armyworm management in maize.