Abstract
In Armadillidium vulgare, the female external genitalia (cuticular copulatory apparatus) consist of a copulatory opening and a spermathecal duct. Adult females change the structure of the genitalia at molting during a reproductive cycle. This study was done to investigate the relationship between the structural change of the genitalia and their reconstruction at the non-parturial (normal) and parturial (reproductive) molts. When females have immature ovaries at molting, they completely cast off the genitalia, together with the old exoskeleton, and reconstruct new genitalia of a non-reproductive type. On the other hand, females with mature ovaries cast off the copulatory openings together with the old exoskeleton at parturial molting. However, the old spermathecal ducts are retained in the oviducts through and after molting. In females with mature ovaries, new genitalia of a reproductive type are not reconstructed at the parturial molt. The present observations demonstrate that adult females change the structure of the genitalia at molting in accordance with the degree of ovarian maturation. The non-reproductive type genitalia are reconstructed at the nonparturial molt but the reproductive type genitalia are not reconstructed at the time of the parturial molt in A. vulgare.
