There are various species of bedbugs with slight differences in the way they reproduce and their lifestyle. This article is an overview of the general lifecycle of most bedbugs, which includes six significant transformations and a unique method of reproduction.
In addition to the egg, there are six main life stages of a bed bug: five immature nymph life stages followed by a final sexually mature adult stage. These life stages of a bed bug are as follows:
- Egg (approximately 1 mm in size)
- 1st stage nymph (approximately 1.5 mm in size)
- 2nd stage nymph (approximately 2.0 mm in size)
- 3rd stage nymph (approximately 2.5 mm in size)
- 4th stage nymph (approximately 3.0 mm in size)
- 5th stage nymph (approximately 4.5 mm in size)
- Adult bedbug (approximately 5.0 mm in size)
At each stage, the bedbugs discard their outer exoskeleton through a process known as ecdysis. They must feed with at least one blood meal before shedding each exoskeleton and must complete this cycle six times before reaching fertile adulthood. Each life stage typically lasts about a week, depending on environmental factors such as temperature and food availability.
Once a bedbug has reached maturation and is classed as an adult, it is possible for the bedbug to mate with another and reproduce.
Reproduction of Bedbugs
Bedbugs mate through a process known as traumatic insemination. The females have a reproductive tract that functions during oviposition, although this is not used for sperm insemination. Traumatic insemination refers to the piercing of the female’s abdomen by the hypodermic penis of the male, with ejaculation into the mesospermalege of the body. The sperm then travels to sperm storage structures known as seminal conceptacles. Over time, fertilization occurs in the ovaries of the female.
In some cases, male bedbugs attempt to mate with other males via traumatic insemination, usually due to sexual attraction related to the size of the bug. Males who are mounted may be severely injured, as they lack the spermalege organ that females have evolved for protection. Instead, males may excrete alarm pheromones to prevent the traumatic insemination.
Fertilization leads to the completion of the ovary development and allows for egg production in the corpus allatum. The sperm can be carried in the conceptacle of the female, where the body temperature is optimal for conservation, for an extended period of time.
The female then lays fertilized eggs until all the sperm in her conceptacle have been used, possibly generating several hundred eggs in this time. Following the depleted supply of sperm, the female lays several eggs that are sterile. The quantity of sterile eggs depends on the nutritional status of the female and is independent of the sperm.
Cimexlectularius males have microbes on their genitals that damage their sperm; rendering them incapable of fertilizing female eggs. However, to cope with this, the males have evolved to ejaculate antimicrobial substances to protect the sperm from damage, so that they can still reproduce.
Reviewed by Susha Cheriyedath, MSc