Abstract
Chemical analyses of hexane extracts from the male grape borer Xylotrechus pyrrhoderus BATES were performed to clarify the hourly change in contents of sex pheromone components, (2S, 3S)-octanediol (S, S-diol) and (2S)-hydroxy-3-octanone (S-ketol), and the location of the pheromone galnds. The maximum contents were detected at the 8th hr of the photophase where the females responded most frequently to the males. The contents of S, S-diol and S-ketol per male at this time were 240.9 ng and 68.0 ng, respectively. The quantitative ratio of these compounds was about 4 : 1. Analyses of the seven parts of the male insect (i.e., head, prothorax, mesothorax, metathorax, abdomen, legs and elytra) indicated that both compounds were detectable only in the extract from the prothorax. Microscopic observations showed that many pores were present over the entire surface of the male prothorax. These pores were connected to ducts by reservoirs in the cuticle with glandular cells lining the endocuticle. This suggests that the pheromone is produced in the prothorax glands and secreted from the pores.
