How do bed bugs of all species look? - briefly
All bed‑bug species are small, flat, oval insects measuring roughly 4–7 mm in length, reddish‑brown when unfed and paler after a blood meal, with six legs, two antennae, and no wings. Their segmented abdomen expands and darkens after feeding, revealing a characteristic swollen appearance.
How do bed bugs of all species look? - in detail
Bed bugs belong to the family Cimicidae, and despite geographic and taxonomic diversity they share a core body plan. All species are dorsoventrally flattened, oval‑shaped insects lacking functional wings. The head is concealed beneath the pronotum, and a short, needle‑like rostrum projects forward for piercing skin and sucking blood. Six jointed legs end in tiny claws that cling to fabrics and mattress seams. Antennae consist of four slender segments, each bearing sensory hairs. Compound eyes are reduced to simple ocelli, giving a matte appearance.
The most widely encountered species, the common bed bug (Cimex lectularius), measures 4.5–5.5 mm in length, 1.5–2 mm in width, and displays a reddish‑brown hue after a blood meal, fading to a lighter tan when unfed. The tropical species (Cimex hemipterus) is similar in size but often exhibits a slightly darker, mahogany coloration and a more pronounced, glossy dorsal surface. Both species lack distinct markings; subtle variations in the pattern of the dorsal punctures can be observed under magnification.
Other cimicids differ mainly in size and coloration:
- Leptocimex boueti – 3.5–4 mm long, pale cream to light brown; dorsal surface smoother, with fewer punctures.
- Afrocimex constrictus – 5–6 mm, dark brown to black; pronounced ridges along the thorax, giving a “constricted” appearance.
- Cimex pilosellus – 4 mm, uniformly light brown; fine setae cover the pronotum, giving a slightly fuzzy texture.
Nymphal stages across all species progress through five instars. Early instars are translucent, measuring 1.5–2 mm, and become progressively more pigmented after each blood meal. Eggs are ovoid, 0.5 mm long, and white, laid in clusters of 10–50 on seams or crevices.
Key morphological differences useful for identification:
- Size range – smallest species under 4 mm, largest exceeding 6 mm.
- Color after feeding – reddish brown (C. lectularius), darker mahogany (C. hemipterus), deep brown/black (A. constrictus).
- Dorsal sculpturing – smooth (L. boueti) versus ridged (A. constrictus).
- Setae presence – noticeable on C. pilosellus, minimal on others.
All species possess a hard exoskeleton, enabling them to survive long periods without feeding. The consistent anatomical features—flattened oval body, winglessness, piercing rostrum, and five‑instar development—allow reliable identification even when coloration varies due to recent blood meals.