Poneromorph ants show a remarkable diversity in the morphological specialization of the worker’s reproductive apparatus, that allows to distinguish four types: (1) mated workers that have a functional spermatheca and ovaries, and that reproduce like queens, (2) workers have ovaries and a vestigial spermatheca, (3) workers have ovaries but no spermathecae, and (4) workers lost both ovaries and spermatheca. Therefore, comparative studies on the morphological specialization of the worker’s reproductive apparatus in poneromorph ants can provide an important insight into the evolution of caste specialization in social insects. We investigated morphogenesis of worker spermathecae in 13 species of poneromorph ants by histological examination. In workers of type (1), the morphogenesis of the spermatheca occurs at the beginning of the pupal stage, when the spermathecal disc appears as a dorsal evagination of the common oviduct. The thickness of the spermathecal wall in the hilar region, which is important for a functional spermatheca, increases at the end of the pupal stage. This process is very similar in poneromorph queens. In type (2), the spermathecal disc also differentiates, however, the hilar epithelium of the spermathecal wall does not increase in thickness. Consequently the spermatheca remains vestigial and not functional. In type (3), although adult workers have no spermatheca, they show development of the disc, although it disappears by the end of the pupal stage. In types (2) and (3), the timing of the degeneration process varies among species and seems to be associated with the degree of caste dimorphism. In type (4), no evagination of the common oviduct could be observed, not even at the earliest stage.