EFFECTIVENESS OF 4 BLENDS OF EUROPEAN CORN-BORER (LEPIDOPTERA, PYRALIDAE) SEX-PHEROMONE ISOMERS AT 3 LOCATIONS IN SOUTH-CAROLINA

A field study was conducted at Florence, Newberry, and Clemson, South Carolina, to determine the relative attractiveness of four isomeric blends of 11-tetradecenyl acetate to male moths of the European corn borer (ECB), Ostrinia nubilalis (Hubner). The E and Z isomers were formulated in E:Z ratios of 99:1, 97:3, 65:35, and 3:97. Trap capture data indicated that the E pheromone strain of the ECB was predominant at Florence and the Z strain was predominant at Clemson. Both strains appeared to occur sympatrically at Newberry. Pheromone analysis of 46 ECB female moths at Florence indicated that 43 were the E strain and 3 were hybrids. The 99E:1Z pheromone blend captured over four times as many male moths as the 97E:3Z blend at Florence. The 65E:35Z blend captured 5%, 11%, and 12% of the moths at Florence, Newberry, and Clemson, respectively, indicating the possible presence of hybrid moths. The superior performance of the 99E:1Z blend of 11-tetradecenyl acetate should enhance the development of a more effective lure for the E strain of the ECB.