What do male and female bedbugs look like? - briefly
Both male and female bedbugs are small, flat, reddish‑brown insects about 4–5 mm long. Females are marginally larger and develop a swollen, lighter abdomen after a blood meal, whereas males stay smaller and retain a uniformly colored body.
What do male and female bedbugs look like? - in detail
Bedbugs (Cimex lectularius) are small, wingless insects about 4–5 mm long, oval‑shaped, and dorsally flat. Their exoskeleton is a glossy brown when unfed and turns reddish‑brown after a blood meal. Both sexes share this general coloration and body plan, but several morphological details allow reliable separation.
- Overall size and shape – Males tend to be slightly slimmer; females possess a broader, more rounded abdomen that expands markedly after feeding or during egg development.
- Abdominal tip – In dorsal view the male’s posterior segment ends in a pointed, sclerotized tip (the aedeagus). The female’s tip is blunt and lacks this projection.
- Genital region – The male exhibits a visible pair of genital papillae near the ventral margin of the last abdominal segment. Females have a concealed spermatheca and a subtle ovipositor opening, neither of which is externally prominent.
- Thoracic features – Both sexes have three segmented antennae of equal length; the antennae are not useful for sex discrimination.
- Legs – Six legs end in small claws; leg morphology is identical in males and females.
When observed under magnification, the combination of a pointed male abdomen and a rounded female abdomen provides the clearest distinction. Color, size, and overall body plan remain consistent across sexes, with the abdominal morphology being the primary diagnostic criterion.