Sex pheromone biosynthesis in Ostrinia zaguliaevi, a congener of the European corn borer moth O. nubilalis

In order to clarify the biochemical basis to the divergence of sex pheromones in the genus Ostrinia (Lepidoptera: Crambidae), the pheromone biosynthetic pathway in O. zaguliaevi, a close relative of the European corn borer O. nubilalis, was investigated. Deuterium-labeled hexadecanoic or tetradecanoic acids were topically applied to the surface of the pheromone gland, and the incorporation of the label into pheromone components and their putative precursors was determined. It was suggested that the two components shared by O. zaguliaevi and O. nubilalis, (E)-11- and (Z)-11-tetradecenyl acetates, are biosynthesized from hexadecanoic acid through one round of chain shortening, Δ11 desaturation, reduction, and acetylation. An additional component specifically found in O. zaguliaevi, (Z)-9-tetradecenyl acetate, is likely to be produced by Δ11 desaturation of hexadecanoic acid, one round of chain shortening, reduction, and acetylation. Non-production of (Z)-9-tetradecenyl acetate in O. nubilalis was suggested to be due to the blockage of chain shortening from (Z)-11-hexadecenoate to (Z)-9-tetradecenoate.