Controlling fall armyworm (Spodoptera frugiperda) in soybean: a comparative study

Soybeans have become an important crop in Brazil, with production increasing over the years. However, this increase has been accompanied by phytosanitary problems, leading to a decline in productivity due to damage caused by insects. The Spodoptera frugiperda is a caterpillar that has been identified in soybean crops in recent years, causing damage and increasing production costs, which in turn impedes crop growth and decreases overall productivity. This research was carried out to evaluate the effectiveness of traditional chemical insecticides (old products) and modern chemical insecticides (new products) in controlling S. frugiperda in soybean crops. The experiments were carried out in a greenhouse with a controlled environment and in the Agricultural Entomology Laboratory of the University of Passo Fundo (UPF), in Passo Fundo, RS. For the study, third-instar larvae of S. frugiperda were used, raised in the laboratory on a synthetic diet. The study was structured in a completely randomized design and consisted of two trials, each with seven treatments: the first trial tested traditional insecticides, while the second examined modern alternatives. Both trials included a control group. The results were subjected to statistical analysis, which consisted of analysis of variance and comparison of means using the Tukey test, with a significance level of 5%. In conclusion, the results suggest that both traditional and modern insecticides have potential for managing third-instar larvae of S. frugiperda in the Passo Fundo-RS region, when applied in specific sections within soybean fields.