Identification and electrophysiological activity of a novel hydroxy ketone emitted by male cereal leaf beetles.

Comparisons of collections of volatiles from male and female Oulema melanopus, feeding on host foliage (oats), revealed an electrophysiologically active male-specific compound, (E)-8-hydroxy-6-methyl-6-octen-3-one (7), which is a new natural product. The structure of 7 was elucidated by spectroscopic and microchemical studies and confirmed by chemical synthesis. Antennal electrophysiology showed the sensitive detection of 7 by both sexes, which is consistent with a male-produced aggregation pheromone.