CONTROLE QUÍMICO ASSOCIADO A CONTROLE BIOLÓGICO PARA SPODOPTERA FRUGIPERDA (J.E. SMITH) (LEPIDOPTERA: NOCTUIDAE)

Abstract

The fall armyworm Spodoptera frugiperda (Lepidoptera: Noctuidae) is one of the most significant agricultural pests, causing considerable yield losses in various crops, especially maize. Managing this pest is challenging due to its behavioral habits and resistance to different chemical groups, which calls for effective control alternatives. Two studies were conducted under laboratory conditions to evaluate different control strategies. The first study assessed the chemical insecticide Cyclaniliprole (anthranilic diamide group) at doses of 200 and 400 mL.ha⁻¹, applied to small (1.5 to 2.0 cm) and large (3.0 to 3.5 cm) larvae, monitoring daily mortality and overall efficacy. Results showed that the 400 mL.ha⁻¹ dose was effective, achieving 100% control efficiency in small larvae and 93% in large larvae ten days after application being the only treatments to exceed 80% efficiency. It was also observed that small larvae were more susceptible than large larvae, regardless of the insecticide dose. In the second study, the efficiency of the entomopathogenic bacterium Bacillus thuringiensis (Bt) was tested, applied alone and in combination with a surfactant at different concentrations (0.1%, 0.5%, 1.0%, and 1.5%), and compared to the surfactant alone and the chemical insecticide Cyclaniliprole (anthranilic diamide group), totaling 11 treatments. Daily mortality and efficacy were also evaluated. It was found that B. thuringiensis alone caused 100% mortality eight days after application and was the only treatment with efficiency above 80%. The combination with surfactant did not provide a synergistic effect. Thus, it can be concluded that both the use of B. thuringiensis and Cyclaniliprole at the higher dose are effective alternatives for the control of S. frugiperda under laboratory conditions.