Trapping spodoptera frugiperda (lepidoptera: noctuidae) moths in different crop habitats in Togo and Ghana

Authors: KOFFI, DJIMA - University Of Ghana; AGBOKA, KOMI - University Of Lome; ADKEVO, ANANI KOSSI MAW - University Of Lome; FENING, OKWAE - University Of Ghana; OSAE, MICHAEL - Ghana Atomic Energy Commission (GAECGH); ABOAGE, EBENEZER - University Of Ghana; Meagher, Robert - Rob; Nagoshi, Rodney

Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/17/2021
Publication Date: 4/3/2021
Citation: Koffi, D., Agboka, K., Adkevo, A.U., Fening, O.K., Osae, M., Aboage, E., Meagher Jr., R.L., Nagoshi, R.N. 2021. Trapping spodoptera frugiperda (lepidoptera: noctuidae) moths in different crop habitats in Togo and Ghana . Journal of Economic Entomology. https://doi.org/10.1093/jee/toab048.
DOI: https://doi.org/10.1093/jee/toab048

Interpretive Summary: The fall armyworm is the primary pest of corn production in South America and in portions of the southeastern United States. In 2016, severe outbreaks of fall armyworm were reported in several western and central African countries, representing the first indication of the species establishing itself in the Eastern Hemisphere, where it now poses a significant threat to African agriculture. The ability to reliably and efficiently identify the presence of this moth on crops depends on the specificity of the pheromone traps used to attract the moths. Scientists at USDA-ARS, Center for Medical, Agricultural and Veterinary Entomology, Gainesville, Florida, in collaboration with colleagues in the African institutions of the University of Ghana, the Université de Lomé (Togo), Ghana governmental agencies collected and genetically characterized moth specimens from maize and sorghum fields in Togo and Ghana to compare the efficacy and specificity of two different classes of fall armyworm pheromone lures. This study confirms previous indications that a three-component (3C) lure is more attractive to the fall armyworm found in Togo than a two-component (2C) blend and extends this finding to show that this effect is consistently true in multiple maize and sorghum habitats. Equally important for more efficient pheromone trapping are the findings on lure specificity. While the 3C lure attracted significantly more non-target species in both maize and sorghum habitats, this was more than offset by the higher attractiveness to fall armyworm. As a consequence, the 3C lure displayed a lower percentage of non-target captures relative to fall armyworm than the 2C in both maize and sorghum habitats. Based on these observations, we can propose the best pheromone blend for use in grain crops in these countries.

Technical Abstract: The economic impact of the invasion of Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) into Africa has so far been limited to maize agriculture but could potentially impact many other crops. Trapping based on pheromone lures provide a cost-effective method for detecting this important pest (commonly known as fall armyworm) and will be essential for large-scale monitoring of populations to determine geographical distribution and migration behavior as the species equilibrates to its new environment. However, the effective use of pheromone trapping requires optimization for a given location for accurate and efficient monitoring. This study expands on an earlier report comparing different fall armyworm lures by examining trap performance in two different crop habitats at multiple locations in Ghana and Togo. Comparisons were made between two-component and three-component lures that previously showed regional differences in efficacy in the United States. The results describe differences in the sensitivity and specificity of the lures depending on location, with the information identifying the optimal lure for use in the Togo and Ghana regions. In addition, the temporal trap capture profiles over two growing seasons provide insight into how the population dynamics of the fall armyworm in Togo and Ghana might influence the timing and magnitude of infestations in the two countries.