Comparison of pheromone trap design and lures for Spodoptera frugiperda in Togo and genetic characterization of moths caught

• Published in: Entomologia experimentalis et applicata 2019-06, Vol.167 (6), p.507-516
• Main Authors: Meagher, Robert L., Agboka, Komi, Tounou, Agbeko Kodjo, Koffi, Djima, Agbevohia, Koffi Aquilas, Amouze, Tomfeï Richard, Adjévi, Kossi Mawuko, Nagoshi, Rodney N.
• Format: Article
• Language: English
• Subjects: Agricultural economics; Butterflies & moths; COI gene; Diagnostic systems; fall armyworm; Field tests; Genetic markers; host strain markers; integrated pest management; IPM; Lepidoptera; Leucania loreyi; maize; monitoring; Noctuidae; Pheromone traps; Pheromones; rice; Spodoptera frugiperda; Tpi gene; Western Hemisphere
• ISSN: 0013-8703; 1570-7458
• DOI: 10.1111/eea.12795

Fall armyworm, Spodoptera frugiperda (JE Smith) (Lepidoptera: Noctuidae), is a pest of grain and vegetable crops endemic to the Western Hemisphere that has recently become widespread in sub‐Saharan Africa and has appeared in India. An important tool for monitoring S. frugiperda in the USA is pheromone trapping, which would be of value for use with African populations. Field experiments were conducted in Togo (West Africa) to compare capture of male fall armyworm using three commercially available pheromone lures and three trap designs. The objectives were to identify optimum trap × lure combinations with respect to sensitivity, specificity, and cost. Almost 400 moths were captured during the experiment. Differences were found in the number of S. frugiperda moths captured in the various trap designs and with the three pheromone lures, and in the number of non‐target moths captured with each lure. The merits of each trap × lure combination are discussed with respect to use in Africa. A nearly equal number of COI‐CS (161) and COI‐RS (158) moths was captured with no differences found in COI marker proportions among traps or lures. However, the diagnostic rice strain marker Tpi was rarely found. Overall, the genetic characterization of the pheromone trap collections indicated a consistent distribution of genetic markers from 2016 to 2017, suggesting a population at or near equilibrium. In Togo (West Africa), bucket traps with either 2, 3, or 4 pheromone components captured more fall armyworm moths (Lepidoptera: Noctuidae) than sticky traps. A locally produced trap, which is much less expensive, did well in capturing moths. Genetic analysis of moths suggested frequencies of host strain similar to larval collections in Togo in 2016. This consistent distribution of genetic markers suggests a population at or near equilibrium.