Mating disruption of Spodoptera frugiperda (Smith, 1797) (Lepidoptera: Noctuidae) using microencapsulated pheromone in cotton.

The fall armyworm (FAW), Spodoptera frugiperda, has increased in importance as a pest over the past decade in Brazilian cotton fields. The limited efficacy of conventional management tools and rapid development of insecticide/ insecticidal proteins resistance is forcing growers to search for new and more sustainable solutions. Here, we report the results from two studies utilizing a microencapsulated sprayable pheromone formulation in Brazilian cotton fields. The first study aimed to define optimal timing to initiate spray applications, optimal number of spray applications and appropriate intervals between spray applications. The second study was a large-scale effort to estimate the efficacy provided by the pheromone sprayable formulation in reducing mating (using trapping reduction as a surrogate measure) and subsequent damage to cotton plants. The highest FAW male moth suppression was achieved when pheromone was sprayed 10 times at an interval of 7-10 days between applications starting at the cotton first headpin square. In large-scale plots (e.g. 40-200 ha), overall median trapping reduction was estimated as 82% (95% CI: 76-87%) in pheromone-treated areas compared to the control plot, over the evaluated period. Additionally, pheromone treatment resulted in an overall median of 27% less damaged reproductive structures (95% CI: 17-37%) when compared to nontreated areas. Our results demonstrate the effectiveness and feasibility of mating disruption as a selective and nontoxic behavioral tool to manage FAW in cotton as an area-wide approach. It represents a key step for developing more sustainable methods for pest management. © 2025 Society of Chemical Industry.