Unusual pheromone chemistry in the navel orangeworm: novel sex attractants and a behavioral antagonist

Using molecular- and sensory physiology-based approaches, three novel natural products, a simple ester, and a behavioral antagonist have been identified from the pheromone gland of the navel orangeworm, Amyelois transitella Walker ( Lepidoptera: Pyralidae). In addition to the previously identified ( Z, Z)-11,13-hexadecadienal, the pheromone blend is composed of ( Z, Z, Z, Z, Z)- 3,6,9,12,15-tricosapentaene, ( Z, Z, Z, Z, Z)- 3,6, 9,12,15- pentacosapentaene, ethyl palmitate, ethyl-( Z, Z)-11,13- hexadecadienoate, and ( Z, Z)-11,13-hexadecadien-1-yl acetate. The C-23 and C-25 pentaenes are not only novel sex pheromones, but also new natural products. In field tests, catches of A. transitella males in traps baited with the full mixture of pheromones were as high as those in traps with virgin females, whereas control and traps baited only with the previously known constituent did not capture any moths at all. The navel orangeworm sex pheromone is also an attractant for the meal moth, Pyralis farinalis L. (Pyralidae), but (Z, Z)-11,13-hexadecadien-1-yl acetate is a behavioral antagonist. The new pheromone blend may be highly effective in mating disruption and monitoring programs.