Evaluation of the seasonal fluctuation of populations of the armyworm, Spodoptera frugiperda (J. E. Smith, 1797) (Lepidoptera: Noctuidae) and its natural enemies in maize crops in Togo

Abstract

ABSTRACT Objective: to evaluate the seasonal fluctuations of S. frugiperda and its natural enemies in maize farming in Togo. Methodology and Results: It consisted in surveying fields in twenty-seven (27) prefectures during the period from October 2019 to November 2021. It consisted in surveying fields and collecting data such as egg, larva and pupa clusters, infestation rates and the main natural enemies encountered according to the FAO "W" method. Then, the collected data were reared in the laboratory for the emergence of potential natural enemies over two seasons. Conclusions and application of findings: It was found that infestation rates; number of egg clusters and larvae; emergence rate and natural enemies of S. frugiperda varied not only according to the survey area, but also and especially according to the season. The infestation rates over the two seasons ranged from 62.55 to 32.55%. On average, the number of larvae was higher in the great season (0.87) compared to the short season (0.41). Meanwhile, the adults emergence ranged from 38.22 to 100.00%; therefore, there are many natural enemies obtained such as Cotesia icipe; Campotelis sp., Trichogramma pretiosum, Winthemia trinitatis, Doru luteipes, Geocoris punctipes and Hexamermis sp. candidate to control S. frugiperda. Additional experiments are however necessary to evaluate climatological aspects on the life table parameters of the main candidate natural enemies. Keywords: maize, S. frugiperda, natural enemies, sustainable management, Togo.