in Diptera, intromittent organ as a whole (Tuxen, after authors), intromittent organ as far as fused with penis valves (Tuxen, after Abul Nasr), or distiphallus, q.v. (Tuxen, after authors, Snodgrass); in Chironomidae (Diptera), intromittent organ resulting from combination of gonapophyses IX and surrounding phalli (Saether); in Culicidae (Diptera), central body of phallosome or distal part of phallus (Harbach and Knight); in Siphonaptera, the external part of the phallosome including the end chamber that bears a large basal apodeme (Rothschild and Traub); in Hymenoptera, bilobate intromittent organ (Gauld and Bolton), penis and penis valves (Tuxen, after Beck), or entire genitalia (Tuxen, after Timberlake).
An aedeagus (plural aedeagi) is a reproductive organ of male insects through which they secrete sperm from the testes during copulation with a female insect. The sperm contains capsules called spermatophores, which contain the spermatozoa. In addition to the spermatophores, in some insect species the aedeagus also discharges a spermatophylax, which serves as a nutriment to the female.