Subgeneric affiliation of Ropalidia thailandia Gusenleitner: a case showing ambiguity of the subgenera of Ropalidia Guérin-Méneville (Hymenoptera: Vespidae: Polistinae)

The subgeneric affiliation of Ropalidia thailandia Gusenleitner, 1994, is reexamined. Gusenleitner (1994) placed this species in the subgenus Icarielia, in particular comparing it with R. decorata. Examination of characters not mentioned by Gusenleitner suggests instead that R. thailandia belongs to the R. stigmagroup, which is not included in the subgenus Icarielia. The case of R. thailandia shows that the subgenera of the genus Ropalidia are still ill-defined.