Polistes wasps are primitively eusocial insects with less specialized female castes. In their societies, aggressive behaviors among females play important roles to regulate their reproductive hierarchies. In addition, cuticular hydrocarbon profiles (CHCs) reliably provide information about the fertility differences among the females. Previous studies have suggested that unmated egg-laying workers in orphaned colonies produce CHCs resembling to those of queens. It has been predicted that caste determination in Polistes wasps should be absent or occur in post-emergence period because workers seem to be totipotent.

Workers of Polistes snelleni are capable of reproducing female offspring directly via fertilized eggs. We compared behaviors and CHCs of females in queenright and orphaned colonies. Egg-laying workers in orphaned colonies showed aggressive behavior more frequently than queens. In addition, there were differences in CHCs between queens and workers. Although mated egg-laying workers showed rather similar CHC profiles to queens’ CHCs, those of other workers were far distinct from queens’. These results suggest that the CHC profiles of the female wasps are honest signals reflecting their fertility and caste differences. Because there were behavioral and chemical differences between queens and workers, mating status seems to be determinant effect on the females status in P. snelleni.