Sex pheromone of the stable fly

The cuticular alkenes of the female stable fly,Stomoxys calcitrans (L), which were responsible for inducing male fly copulatory behavior are (Z)-9-hentriacontene, (Z)-9-tritriacontene, 13-methyl-1-hen-triacontene and 13-methyl-1-tritriacontene. The identifications of the branched alkenes and the synthesis of these four compounds are described. Bioassays indicate that these materials in combination with previously described methyl branched alkanes are more active than the individual components.