The E and Z pheromonal strains of the European corn borer, Ostrinia nubilalis, are characterized by female production of and male preference for opposite blends of (E)-11-and (Z)-11-tetradecenyl acetate. It is known that the pheromone production is controlled by an autosomal gene and that the males' behavior is determined by a sex-linked gene. A third gene, autosomally inherited, has been shown to determine the organization of the male pheromone receptors. In the present study the linkage relationship between the autosomal genes controlling sex pheromone production and male olfactory sensilla was investigated. A recombination experiment showed unequivocally that the genes determining the variation in pheromone production and male pheromone receptors are not closely linked and are most likely inherited independently.