The vast majority of ant colonies contain a fully-functional queen (are queenright). In these colonies direct reproduction by workers is usually prevented by queen-induced regulatory mechanisms. However, some ant colonies inhabit multiple nests sites (are polydomy), with the queen present in only one nest and only workers inhabiting other nests. This might allow workers to escape queen control and to reproduce. However, whether worker-produced brood survives after colony reunion in seasonally polydomous species remains unclear. In several species, worker-produced eggs and male-destined larvae are selectively destroyed in queenright colonies. Giehr et al. (2020) tested whether workers discriminate between queen- and worker-produced larvae during colony reunion. They examined the reproductive success of workers in queenless subcolonies of Temnothorax crassispinus. They show that present brood did not inhibit worker reproduction but had a positive effect on worker lifespan. Larvae produced by workers were readily integrated into queenright subcolonies during colony reunion and these larvae successfully developed into adult males (Giehr, Wallner et al., 2020).
Giehr, Senninger et al. (2020) found that while male quality traits varied considerably among colonies they differed only slightly between queen- and worker-produced males. They also found that worker-produced males outnumbered queen-produced males and males also had longer lifespans, but under certain rearing conditions sperm from queen-produced males had a higher viability.
Shimoji et al. (2018) found that in at least some Diacamma species worker-based policing of the reproductive activity of other workers depends strongly on the colony growth stage. Reproduction by workers was suppressed by worker policing when the colony was small and in the growth phase, whereas in large, mature (reproductive) colonies worker policing was relaxed and worker-produced males emerged.
- Giehr, J., Senninger, L., Ruhland, K., Heinze, J. 2020. Ant workers produce males in queenless parts of multi-nest colonies. Scientific Reports 10, 2152 (doi:10.1038/s41598-020-58830-w).
- Giehr, J., Wallner, J., Krüger, T., Heinze, J. 2020. Body size and sperm quality in queen‐ and worker‐produced ant males. Journal of Evolutionary Biology 33, 842–849 (doi:10.1111/jeb.13616).
- Shimoji, H., T. Kikuchi, H. Ohnishi, N. Kikuta, and K. Tsuji. 2018. Social enforcement depending on the stage of colony growth in an ant. Proceedings of the Royal Society B-Biological Sciences. 285:6 (doi:10.1098/rspb.2017.2548 10.1098/rspb.2017.2548).