The production of Drosophila cuticular hydrocarbons, including contact pheromones, is under polygenic control. To investigate X-linked loci, EMS mutations were induced in Drosophila simulans flies. A mutant strain was discovered which in both sexes show a reduction in the biosynthesis of both 7-tricosene (7-T) the species contact pheromone and all other linear hydrocarbons. The locus controlling this effect, kété, is recessive and was localized to I, 18.5. Unlike a previously identified gene on the second chromosome of this species, Ngbo, kété does not affect the ratio of 7-T:7-pentacosene (7-P). Other reproductive characteristics are also affected, including egg-hatching. However, courtship behaviors in both sexes appear normal.