Social insect queen pheromones can be interpreted as the queen’s means of sterilizing her workers, or as an honest signal of queen presence that benefits both parties. Co-mapping worker reproductive behaviour and queen cuticular hydrocarbon (CH) composition and quantity on a phylogeny of 21 stingless bee species showed that there are no associations between these traits. Furthermore, three species that have independently evolved facultative worker sterility are unexceptional in their queen CH. Combined, our analysis suggests that the action of stingless bee queen CHs are best interpreted as a signal of queen presence and not as a chemical contraceptive.
The authors are grateful to E.A.B. Almeida (FFCLRP - Universidade de São Paulo) for his important contributions regarding the interpreting and coding of characters, and the analysis of phylogenetic comparative data, which were crucial to the initial development of this study. The authors are also thankful to T. Heard for providing Australian stingless bees queens. This research was supported by FAPESP (L.G.E. 2013/ 01918-1; T.M.N. 2013/09263-4, N.P.L. 2014/50265-3) and CNPq (T.M.N. 165823/2015-1).
Supporting data and R code.