Abstract
Testicular development and spermatogenesis were studied in Papilio xuthus larvae and pupae of both diapause and non-diapause types. The prompt differentiation of the sex cells was observed during fourth and fifth (final) instar larvae, and eupyrene sperm bundles were first observed on the first day of the fifth instar in both types. In the diapause type, the spherical spermatids began to degenerate at this stage, and on the fourth day of the fifth instar the spermatogenesis stopped completely, and degeneration occurred in all the spermatidal cysts and sperm bundles at pupal stage. In the non-diapause type, however, spermatogenesis proceeded on throughout fifth instar, and apyrene sperm bundles appeared in pupae.
