Silencing expression triggers three-level pheromonal feminization in males.

Doublesex (Dsx) has a conserved function in controlling sexual morphological differences in insects, but our knowledge of its role in regulating sexual behaviour is primarily limited to . Here, we show with the parasitoid wasp that males whose gene had been silenced (-i) underwent a three-level pheromonal feminization: (i) -i males were no longer able to attract females from a distance, owing to drastically reduced titres of the long-range sex pheromone; (ii) -i males were courted by wild-type males as though they were females, which correlated with a lower abundance of alkenes in their cuticular hydrocarbon (CHC) profiles. Supplementation with realistic amounts of synthetic ()-9-hentriacontene (9C31), the most significantly reduced alkene in -i males, to -i males interrupted courtship by wild-type conspecific males.