The male genital tract and aedeagal components of the Diptera with a discussion of their phylogenetic significance Sinclair, Bradley J. Borkent, Art Wood, D. Monty Zoological Journal of the Linnean Society 2007 2007-08-31 150 4 711 742 6277P 79304 [349,551,400,424] Insecta Ptychopteridae Animalia Diptera 14 725 Arthropoda family   Description ( Fig. 6D, E)  Testis:Each testis is long, slender, and spindleshaped, often yellowish-orange in dissections. The testes of  Ptychopteranr  japonicaAlexanderand  Ptychoptera contaminata(L.) are positioned far posteriorly, lying near the accessory gland complex.  Epididymis:Not differentiated.  Vas deferens:In  Ptychoptera lacustrisMeigen( Fig. 6E), the vasa deferentia extend posteriorly to the level of the posterior chambers of the accessory gland complex, where they turn medially, fuse, and run anteriorly before arching abruptly into the accessory gland complex ( Just, 1973). In  Ptychoptera contaminata, the vasa deferentia appear little differentiated from the testes, extending first anteriorly dorsal to the testes. The vasa deferentia of  Ptychopteranr  japonica( Fig. 6D) also run immediately anteriorly and empty into the apex of a large three-chambered accessory gland complex.  Accessory gland and seminal vesicle:In  Ptychoptera lacustris, the accessory gland complex is divided into an elongate and slender anterior section connected to a rounded posterior gland by a short duct ( Fig. 6E). The accessory gland complex of  Ptychopteranr  japonica( Fig. 6D) is fused along the midline, forming a three-chambered gland. In  Ptychoptera contaminata, the genital tract is folded over itself several times and what appear to be vasa deferentia could in fact be additional sections of the accessory gland complex lying beneath paired, rounded chambers. In this species, the vasa deferentia are quite elongate, extending anteriorly before strongly arching posteriorly as clear, thin-walled ducts that separately enter the paired posterior chambers.  Ejaculatory duct:The ducts are short, lined with thick muscles, and unite prior to entering the sperm pump ( Just, 1973). The ejaculatory ducts of  Ptychopteranr  japonicaand  Ptychoptera contaminataare bent sharply upon exiting the seminal vesicles and then arch to the sperm pump.  Ejaculatory apodeme, sperm pump, and aedeagus: Ptychoptera lacustrisand  Ptychoptera contaminatapossess a large median ejaculatory apodeme and a pair of apodemes extended from the paramere, which compress the sperm pump [see explanation in Just (1973)]. In contrast,  Ptychopteranr  japonicapossesses a large sclerotized, spherical sperm sac and lacks an ejaculatory apodeme [similar to that of  Bittacomorpha clavipes(Fab.); see Wood (1991: fig. 10)].  Remarks:The genital tract is quite variable in the genus  Ptychoptera.The configuration of the vasa deferentia is similar to that observed in Bibionomorpha and Culicomorpha. The accessory gland complex comprises a number of chambers that are separated, connected by slender ducts or fused into a single gland.