Efficacy of Novel Insecticides against Fall Armyworm, Spodoptera frugiperda (J. E. Smith), in Maize

Background: Fall armyworm, Spodoptera frugiperda (J. E. Smith), is an invasive pest of maize, making evaluation of insecticidal treatments important under local field conditions. Aim: This study assessed the efficacy of broflanilide 20% suspension concentrate (SC) against fall armyworm in maize and compared it with two other insecticides. Methods: Field experiments were conducted at Vallampadugai village, Cuddalore district, Tamil Nadu, during Rabi 2023–2024 and Kharif 2024. Seven treatments, including broflanilide at 30, 50, 70 and 90 g active ingredient/ha, emamectin benzoate, chlorantraniliprole and an untreated control, were evaluated in a randomised block design with three replications. Two sprays were applied at 15 and 30 days after sowing. Larval populations and whorl damage were assessed after treatment, and grain yield was recorded. Results: Broflanilide at 90 g active ingredient/ha consistently showed the greatest efficacy among the treatments. At 14 days after the second spray, larval populations were 0.43 and 0.37 larvae per plant in Rabi and Kharif, respectively, corresponding to reductions over the control of 90.65% and 91.72%. Whorl damage after the second spray was 5.43% in Rabi and 3.88% in Kharif. Grain yields reached 13.03 and 12.55 t/ha, compared with 9.38 and 9.24 t/ha in the respective untreated controls. Conclusion: Under the conditions examined, broflanilide 20% SC at 90 g active ingredient/ha provided the strongest suppression of fall armyworm and the highest grain yield among the evaluated treatments.