The post-ovarian genital complex (POGC) is ectodermal in origin and confined to the 8th abdominal segment. It consists of a pair of lateral, elliptical spermathecae, a median, spherical bursa copulatrix and a ventral, pouch-like, rectangular muscular vagina, — In the mature female the spermathecae, bursa copulatrix and vagina are lined with a thick cuticular intima. The vagina is externally wrapped in a thick muscle coat formed of four pairs of sternal muscles. The ducts from the spermathecae open anterolaterally into the bursa copulatrix. The latter opens posteriorly into the vagina through a well defined bursa communis. The fertilization pore is a cuticular tunnel formed from a middorsal and two lateral cuticular plates. The common oviduct opens mid-ventrally into the vagina through a spindle-shaped cuticular orifice. – Soon after ecdysis from the penultimate to the last instar larva, a trilobed epithelial structure is formed from a globular mass of epithelial cells present in the middle of the inner surface of the 8th sternum. By the 4th day the bursa copulatrix and vagina are differentiated from the dorsomedian and ventrolateral lobes of the trilobed structure, respectively. The spermathecae bud off from the lateral walls of the bursa copulatrix. The fertilization pore and bursa communis are formed by the 20th day. Prior to the final moult, the post-ovarian genital complex is fully formed but lies in a collapsed state. In the newly emerged adult, the POGC is lined internally with a distinct, thin cuticle and covered externally with a poorly developed muscle coat.