Effect of aging on pheromone emission from a commercial beet armyworm (Lepidoptera: Noctuidae) lure and trap efficiency.
The effect of aging on a commercial pheromone-based lure for attractiveness to male adult beet armyworms, Spodoptera exigua (Hübner), 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-ol. In field assays conducted in the Lower Rio Grande Valley, Texas, for 9 wk (June-August 2000) and for 8 wk (March-May) in Tamaulipas, Mexico, 0-1-wk-old lures collected greater than four-fold more male beet armyworm adults than lures that had been aged for 3-4 wk. Using solid phase microextraction and gas chromatographic analysis of the volatiles, mean (Z,E)-9,12-tetradecadienyl acetate emission declined by 32% after 5 wk of aging in a ventilated environmental chamber at 29.4 degrees C, 3.5% RH, to simulate subtropical summers. Mean (Z)-9-tetradecen-1-ol emission was reduced by 62% after 4 wk of aging. Under the tropical and subtropical conditions of this study, the capacity of the lure to attract moths into the trap declined after aging for 3 wk. The blend ratio (Z,E) -9,12-tetradecadienyl acetate: (Z)-9-tetradecen-1-ol declined 29% when the lure was aged for 5 wk. This study will assist in the development of a standard trapping system for assessing adult beet armyworm populations in the tropical and subtropical conditions to which the species is endemic.
Showler
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USDA-ARS APMRU, Weslaco, TX 78596, USA.
Salgado
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Fraser
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Robacker
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D000818:Animals; D007300:Insect Control / Q000379:methods*; D008297:Male; D010675:Pheromones / Q000737:chemistry*; D011156:Population Density; D018411:Spodoptera / Q000502:physiology*; D013997:Time Factors; D014835:Volatilization
D010675:Pheromones; C010411:insect attractants