Chemical identification and behavioral characterization of male wing pheromone of Ephestia elutella (Pyralidae)

Behavioral and chemical evidence is presented for the identity of the male wing pheromone of Ephestia elutella (Hübner) and the role of this pheromone in courtship success is evaluated. Males with the forewing removed experienced a mating success rate less than half of that of either intact males or males that had only the wing gland area remaining of their forewings. GC-MS analysis and microchemical reactions indicated the presence of (E)-phytol and a series of saturated γ-lactones in a methylene chloride extract of the wings. Using an assay of female courtship behavioral response, (E)-phytol was found to evoke an intermediate level of response in females when presented alone, while the complete array of insect-derived γ-lactones produced no significant response. The combination of either γ-decalactone or γ-undecalactone with (E)-phytol in a 1:2 ratio, however, elicited a female response equivalent to that produced by the unfractionated wing extract.