Solid-phase microextraction and cuticular hydrocarbon differences related to reproductive activity in queenless ant Dinoponera quadriceps

We extracted the cuticular hydrocarbons from live Dinoponera quadriceps ants (10 colonies collected from Brazil) with the solventless solid-phase microextraction (SPME) technique. Gas chromatography of the SPME samples (N = 233 measurements) compared with pentane extracts (N = 10) resulted in similar profiles. Eighty-one compounds belonging to the main long-chain hydrocarbon families were identified by GC-MS. There is no morphologically specialized queen in D. quadriceps and only one aggressively dominant worker (alpha) mates and reproduces in each colony. The alpha ant (N = 26 individuals) always yielded higher amounts and percentages of g-hentriacontene (9-C-31:1) than her sterile nestmates (N = 47). Since SPME is not destructive, it allowed for the repeated extraction of the same individuals, demonstrating that the alpha ant (virgin or mated) always had higher levels of 9-hentriacontene. This difference appears related to ovarian activity and may function as a signal of the alpha's dominance status.