Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/5/2004
Publication Date: 4/1/2005
Citation: Showler, A., Salgado, E., Fraser, I., Robacker, D.C. 2005. Effect of aging on pheromone emission from a commercial beet armyworm (Lepidoptera: Noctuidae) lure and trap efficiency. Journal of Economic Entomology. 98(2):373-377. Interpretive Summary: Although beet armyworm lures containing the male sex pheromone have been compared in terms of the trend of trapping efficiency, the trend of trapping efficiency has not been assessed under subtropical field conditions. This evaluation measured a commercial lure's efficiency relative to exposure time in the Lower Rio Grande Valley of Texas and Tamaulipas, Mexico, and changes in emissions of the lure's two principal chemical components. The results will contribute to the development of a standard trapping system that assesses adult beet armyworm activity in subtropical conditions, which is particularly important relative to possible secondary pest outbreaks associated with boll weevil eradication efforts in the Lower Rio Grande Valley of Texas.
Technical Abstract: The effect of aging on a commercial sex pheromone-based lure for male beet armyworm adults was assessed in terms of trapping efficiency and volatile emissions of two key components, Z, E-9, 12-tetradecadienyl acetate; and Z-9-tetradecen-1-o1. In the field assays conducted in the Lower Rio Grande Valley of Texas for nine weeks, June-August 2000, and for eight weeks, March-May in Tamaulipas, Mexico, non-aged lures collected >/=4-fold more male beet armyworm adults than lures that had been aged for three weeks. Using solid phase microextraction and gas chromatographic analysis of the volatiles mean Z, E-9, 12-tetradecadienyl acetate emission declined by 32% after five weeks of aging in a ventilated environmental chamber at 29.4°C. Mean Z-9-tetradecen-1-o1 emission was reduced by 62% after four weeks of aging. Emissions of Z-9-tetradecen-1-o1 from the differently aged lures were correlated with cumulative trap captures in Texas and Tamaulipas, but Z,E-9,12-tetradecadienyl acetate probably also played an important role. Under the subtropical conditions of this study, the lure maintains efficiency for two weeks, after which interpretation of trap capture data should account for declining efficiency.