Traumatic Insemination


Mating in C. lectularius is a process which is divided into three stages. The male bedbug seems to have no other mechanism of distinguishing a female other than by trial and error, although it is able to recognise its own species over a distance of 10-15mm. If the male accurately locates a female and she is receptive, then the first stage called spermalege commenses. Both the female and the male must have taken a full blood meal before mating, and if the female has not met this prerequisite, she will attempt to hide her reproductive area from the male (see figure below, from Siva-Jothy 2006).


Assuming the female is prepared, the first stage will involve the female guiding the male intromittent organ to her reproductive area, wherein the male "tastes" her with his intromittent organ. This intromittent organ is about xxxx in length, among the most prominent features of the bug.

The intromittent organ bears sensillae, tiny hairs with receptors which allows the males this sense of taste (see figure below). They can determine whether their current mate has recently copulated and then adjust copulation duration and ejaculate size acordingly. The male ejaculatory pump is connected to the vasa deferentia (the male sperm reservoir) and regulates the transfer of sperm during insemination (Siva-Jothy 2006).


Assuming the female is prepared to mate, she will allow repeated entry in short bouts into her mesospermalege, the female reproductive organ area. Female physiological and anatomical adaptation have directed this penetration into the mesospermalege because it is replete with phagocytic hemocytes. Specifically, notch and cuticular thickening of the right side of the 5th sternite lies directly over a distinct pocket filled with hemocytic cells on the inner surface of the abdominal wall. These hemocytes likely function to protect the female against potential pathogens in the accesory seminal fluid. Accessory gland fluid that is also injected by the paramere goes directly to the blood, leaving visible melanized scars. Multiple wounds will result in the expression of a cuticle repair system. 

After insemination occurs, approximately 30 minutes pass before the sperm become mobile. Once mobile they move forward into the haemocoele, a process that takes some three to four hours. This movement into the haemocoele is the second stage. The spermatozoa then penetrate into the seminal receptacle and gradually move up the oviduct wall. The egg is fertilised in the ovariole before the chorionic membrane is formed, marking the intragenital phase. Eggs are then laid away from the host in the places where the adults reside during the day, with each female laying 2-3 eggs a day throughout her lifespan. If a female is able to take a blood meal at a minimum of twice a week, then egg laying will be continuous, such that her first batch will consist of six to nine usually laid singularly, and then she will immediately begin to develop another batch. These will be laid the following week, with an average of six to seven eggs per week being laid for around 13 weeks. The cream coloured eggs (1mm in length) are cemented on rough surfaces of hiding places, and will hatch within around 10 days at room temperature. This process is temperature-dependent and will take longer in cooler conditions. C. lectularius females stop laying fertile eggs approximately 35 to 50 days after sexual isolation. (Siva-Jothy 2006).