Secondary Sex Pheromone Components of Choristoneura murinana Hb. (Lepidoptera: Tortricidae)

The alkenyl acetates £9-12:Ac, zl l l -12:Ac and Zl l -14:Ac were identified as minor components of the C. murinana female pheromone blend by chemical analyses of volatile pheromone gland constituents and potential pheromone precursors, electrophysiological recordings from single receptor cells, and field trapping tests. Gland washes from virgin females contained these compounds at 3%, 10% and 5%. respectively, the amount of the primary pheromone component Z9-12:Ac already reported. A 0.3% addition of either J l l 1 2 : A c or Z l l -14 :Ac significantly raised trap captures over Z9-12:Ac alone and a 3 3 0 % addition of either minor component revealed maximum captures, not increased further by including both synergists within the same blend. A functional role of the £9-12: Ac could not be established during this study; 3% of it when combined with the pheromonal ratio mixture of the three other components tended to increase trap captures further whereas in various other mixture combinations the £9-12:Ac strongly reduced captures. These inhibitory effects were more pronounced with attractant blends based on Z l l -14 :Ac rather than Zlll-12:Ac. Each blend component activated its own type of antennal receptor cell.