Optimal Sex Pheromone Composition for Monitoring Spodoptera exigua (Lepidoptera: Noctuidae) in Korea

Abstract

The sex pheromone composition for the Korean population of the beet armyworm, Spodoptera exigua (Hübner) (Lepidoptera: Noctuidae) was determined from the abdominal tip extract of virgin females during her calling period. Gas chromatography of the extracts revealed 3 components; Z,E-9, 12-tetradecadienyl acetate ( Z,E-9,12–14: Ac), Z9-tetradecen-1-ol ( Z9–14: OH), and Z9-tetradecenyl acetate ( Z9–14: Ac). In electroantennogram analyses to males, a main component, Z,E-9,12–14: Ac, evoked significantly higher response than did the other two components. Although male moths were broadly attracted to lures, composed of Z,E-9,12–14: Ac and Z9–14: OH with ratios from 9:1 to 1:9, in Andong and Seosan field areas, the 7:3 blend was found to be the most effective. The optimal height of trap location was 1.5 m above ground. Three minor sex pheromone components including Z9-hexadecenyl acetate ( Z9–16: Ac), Z11- tetradecenyl acetate ( Z11–14: Ac), and Z9-tetradecenyl acetate ( Z9–14: Ac) were reported before from local populations. But, in this study, only Z11–16: Ac showed significant synergistic effect on enhancing the attractiveness of the major component blends at ratios of 7:3:1 and 7:3:5 of Z,E-9,12–14: Ac, Z9–14: OH, and Z11–16: Ac.