Unsaturated cuticular hydrocarbons serve as pheromones in insects. In D. melanogaster, these hydrocarbons are sexually dimorphic in both their occurrence and their effects. 7(Z),11(Z)-Nonacosadiene is a cuticular pheromone in female fruit flies that stimulates male courtship behavior. The biosynthesis of this C29 diene appears to be mediated by an elongase with female-based expression.