Abstract
The relationship between the responses of female grape borer Xylotrechus pyrrhoderus and the blend ratios of two synthetic male sex pheromone components, (2S, 3S)-octanediol (S, S-diol) and (2S)-hydroxy-3-octanone (S-ketol), and their synthetic stereoisomers was examined in a wing tunnel. Females were much more attracted by certain mixtures of S, S-diol and S-ketol than by the individual components alone, and sometimes exhibited a hovering style of flying typical of the female to the pheromone-releasing male. The optimum blend ratio of the two components was approximately 80 : 20 of S, S-diol and S-ketol. Females responded similarly to mixtures of R, R-diol or S, R-diol and S-ketol (80 : 20 ratio), but weakly to the mixture of R, S-diol and S-ketol. Furthermore, the mixture of S, S-diol and R-ketol did not elicit notable behavioral response in females; instead, R-ketol acted as an inhibitor.
