In this investigation with the use of surgical methods the role of accessory reproduction organs in the reproduction of Papilio demoleus has been carried out. The spermathecal gland complex (SPC, spermatheca + spermathecal gland) and accessory gland complex (AGC) are some of the most imprtant reproductive organs of this insect. Extirpation and implantation experiments with these complexes show that whereas the entire SPC regulates oviposition through motile sperms that if stores, the spermathecal gland (SPG)as a part of the complex maintains the motility of the sperm apparently by nourishing them with its secretion. The AGC prorides a gluing substance that enable the eggs to stick to the substratum they are laid on but with no role in oviposition.