Monitoring of the Fall Armyworm (Spodoptera frugiperda Walker) Moth for the Determination of Efficient Chemical Control in Zea mays L.

Abstract

Objective: To determine the population dynamics of the fall armyworm (FAW), identify the critical period of highest infestation and to determine the number of agrochemicals applications for its control.

Design/methodology/approach: A monitoring and capture of male FAW moths was conducted using plastic traps with sexual attraction pheromones. A daily count of captured moths was performed during the crop season, the data were plotted to determine the period of highest infestation and the optimal timing for chemical control. Additionally, the number of insecticide applications for FAW control was evaluated, with treatments including none (T0), one (T1), two (T2), three (T3), and four (T4) applications. A randomized complete block design with nine repetitions was used. Before each application, the number of plants with visible damage and its intensity were counted using the Davis visual scale. Statistical analysis of the measured variables was conducted.

Results: The results showed that moths were evenly distributed across the planted surface, and two periods of higher infestation were identified: between 32 to 35 and 70 to 76 days after planting, respectively. The biological cycle of the FAW was between 38 to 41 days. The analysis of variance showed statistical differences (p ≤ 0.001) among the treatments.

Findings/conclusions: Using plastic traps with sexual attraction pheromones is an efficient method for capturing, monitoring, reducing the population, estimate the length of the biological cycle, and identifying the highest infestation period of the FAW. Moreover, two insecticide applications during the periods of highest infestation resulted in optimal control of FAW.