Target specificity of commercial pheromone lures used for monitoring fall armyworm in South Africa

First reported in South Africa in 2016, Spodoptera frugiperda (the fall armyworm) has the potential to inflict substantial crop losses. Early detection, using pheromone-baited traps that attract male moths, is integral to effective management. Two sex pheromone lures (i.e. pheromone compounds and dispensers) that are commercially available in South Africa attract high numbers of non-target moths. During a three-year trial conducted in maize fields in South Africa, we tested an unregistered lure against the two commercially available lures to compare their target specificity, when used in yellow bucket traps. There were no significant differences in S. frugiperda attracted among the lures. However, the unregistered lure (in a bubble cap dispenser) exhibited a higher degree of target specificity, with significantly fewer non-target Noctuidae attracted, than the two commercially available lures (in red and grey rubber septa). There were no significant differences among the lure treatments and unbaited controls in captures of non-lepidopteran insects, which included pest and beneficial species. Target specificity of S. frugiperda sex pheromones is important in reducing bycatch and improving surveillance efforts.