Why is the bedbug white? - briefly
The insect appears pale because its cuticle is thin and largely unpigmented in early stages, giving it a translucent, whitish look, particularly after molting. As it matures, the exoskeleton darkens and the white appearance fades.
Why is the bedbug white? - in detail
Bedbugs display a light coloration during specific life stages and conditions. The pale appearance results from several biological factors.
The cuticle of newly hatched nymphs lacks the dark pigments that develop after successive molts. As the insect ages, melanin and hemoglobin‑derived pigments accumulate, giving the familiar reddish‑brown hue. Immature individuals therefore look almost translucent or whitish.
When a bedbug is crushed, the internal hemolymph, which contains red pigments, mixes with the cuticle, creating a darker smear. The remaining exoskeleton, now devoid of blood, appears almost colorless. This effect is often mistaken for a naturally white specimen.
Eggs laid by females are inherently white. The chorion, a protective outer layer, contains no pigment, making the eggs visible as tiny, opaque spheres on fabric or in cracks.
Environmental factors can also influence coloration. Exposure to low temperatures slows pigment synthesis, prolonging the light‑colored phase of nymphs. Conversely, warm, humid conditions accelerate pigment deposition, leading to faster darkening.
Key points summarizing the causes of the light hue:
- Nymphal stage – early instars lack pigment, appear translucent.
- Eggs – chorion is naturally unpigmented, visible as white.
- Post‑mortem – removal of hemolymph leaves a colorless exoskeleton.
- Temperature – cooler environments delay pigment formation.
Understanding these mechanisms clarifies why bedbugs may be observed as white under certain circumstances.