efficacy of Insecticides and Ecofriendly Options against Spodoptera frugiperda (J E Smith)

The fall army worm Spodoptera frugiperda (J E Smith) is a major pest threatening maize production in Nepal. Field trials were conducted in 2022 and 2023 in Chitwan, Nepal to evaluate the efficacy of chemical and local pest-repellent materials using a randomized complete block design with eight treatments and three replications. Treatments included malathion, azadirachtin, chlorantraniliprole + lambda-cyhalothrin, wood ash, soap solution, sawdust, sugar solution, and an untreated control, applied at 24 and 45 days after maize sowing. Chlorantraniliprole + lambda-cyhalothrin was the most effective in reducing infestation, followed by azadirachtin. Local materials- wood ash, sawdust, and sugar solution- also significantly suppressed pest levels. The highest benefit-cost ratios were recorded for chlorantraniliprole + lambda-cyhalothrin and azadirachtin, with promising returns from local materials. These findings support the integration of chemical and eco-friendly local practices as a sustainable, cost-effective strategy for managing S. frugiperda, particularly for smallholder maize farmers in Nepal.