The male pierces the abdomen of the female with a sclerotized, needle-like paramere and inseminates into her body cavity despite the prescence of a fully functional female reproductive tract … The females of C. lectularius (and most other cimicids) possess an organ called the spermalege. It has two embryologically discrete parts: the ectodermal ‘ectospermalege’ and the mesodermal ‘mesospermalege’. The ectospermalege consists of a groove in the right-hand posterior margin of the fifth sclerite overlying a structurally modified pleural membrane. During traumatic insemination, male bedbugs insert their intromittent organ into this groove, pierce the pleural membrane and so gain access to the female’s haemocoel (body cavity). … Attached to the wall of the haemocoel, directly underneath the external groove, lies its second component: the mesospermalege. During traumatic insemination, sperm and seminal fluid are ejaculated into this haemocyte-containing membrane bound sac. Sperm travel out of the posterior part of the mesospermalege into the female’s haemolymph (blood) from where they migrate to specialized sperm storage structures (the seminal conceptacles) and then on to the ovaries where fertilization takes place.