Nonanal, a new fall armyworm sex pheromone component, significantly increases the efficacy of pheromone lures

Authors: SAVEER, AHMED - North Carolina State University; HATANO, EDUARDO - North Carolina State University; WADA-KATSUMATA, AYAKO - North Carolina State University; Meagher, Robert - Rob; SCHAL, COBY - North Carolina State University

Submitted to: Pest Management Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/15/2023
Publication Date: 3/19/2023
Citation: Saveer, A.M., Hatano, E., Wada-Katsumata, A., Meagher Jr, R.L., Schal, C. 2023. Nonanal, a new fall armyworm sex pheromone component, significantly increases the efficacy of pheromone lures. Pest Management Science. 79(8): 2641-2968. https://doi.org/10.1002/ps.7460.
DOI: https://doi.org/10.1002/ps.7460

Interpretive Summary: Fall armyworm (Lepidoptera: Noctuidae) is a highly polyphagous insect pest, native to the Western hemisphere but has invaded much tropical and subtropical areas of the Eastern Hemisphere. An efficient way to detect new invasions at early stages and monitor and quantify the status of established infestations of this pest is to deploy species-specific synthetic sex pheromone lures in traps. However, fall armyworm lures have limited utility in the field, possibly because of missing sex pheromone components in commercial lures. Scientists with North Carolina State University, in collaboration with a scientist from USDA-ARS, Center for Medical, Agricultural and Veterinary Entomology in Gainesville, Florida, discovered a new compound (nonanal) produced by female moths that when added to traditional pheromone lures, attracted more fall armyworm males in laboratory tests and doubled collections in the field. Thus the addition of nonanal to pheromone lures, can greatly enhance surveillance efficacy of fall armyworm moths ultimately leading to more effective control and decreased crop damage.

Technical Abstract: The fall armyworm (FAW), Spodoptera frugiperda (J.E. Smith), is a global noctuid pest that feeds on more than 350 plant species and limits production of cultivated grasses (e.g., maize, rice, sorghum, sugarcane and wheat), vegetable crops and cotton. An efficient way to detect new invasions at early stages and monitor and quantify the status of established infestations of this pest is to deploy species-specific synthetic sex pheromone lures in traps. Sex pheromones can also be used to control resurgent populations using a mating disruption strategy. However, FAW lures have limited utility in the field, possibly because of missing sex pheromone components in synthetic lures. We reexamined the compounds in the sex pheromone glands of FAW females by GC-EAD, GC-MS, behavioral, and field assays. A new bioactive compound from pheromone gland extracts was detected in low amounts (1% relative to (Z)-9-tetradecenyl acetate (Z9-14:OAc), the main pheromone component) and identified as nonanal. This aldehyde significantly increased attraction of male moths to a mix of Z9-14:OAc and (Z)-7-dodecenyl acetate in olfactometer assays. Adding nonanal to this 2-component mix also doubled male trap catches relative to the 2-component mix alone in cotton fields; however, nonanal alone did not attract any moth. The addition of nonanal to each of three commercial pheromone lures also increased male catches by 30–60% in sorghum and cotton fields. Therefore, pheromone lures that include nonanal should be more effective for surveillance, detection, monitoring and control of FAW populations.