What do bed bug larvae look like? - briefly
Bed bug nymphs are tiny, translucent to pale yellow insects measuring 1–5 mm, with a segmented, wingless body, visible antennae, and six legs on each segment. Their color darkens to reddish‑brown as they molt through successive stages.
What do bed bug larvae look like? - in detail
Bed bug nymphs emerge from eggs as tiny, translucent organisms about 1 mm long. Their bodies are oval, dorsoventrally flattened, and lack wings. The cuticle is initially almost colorless, becoming progressively darker with each molt until the adult’s reddish‑brown hue is reached.
Key visual characteristics:
- Size progression:
1st instar – 1.5 mm, translucent;
2nd instar – 2 mm, faint amber tint;
3rd instar – 2.5 mm, light brown;
4th instar – 3 mm, medium brown;
5th instar – 4 mm, dark reddish‑brown, close to adult coloration. - Body segmentation: Six visible abdominal segments; the thorax bears three pairs of short, stubby legs.
- Head features: Small, rounded head with a pair of simple eyes (ocelli) that appear as tiny dark spots; antennae are short, segmented, and hidden beneath the head capsule.
- Mouthparts: Piercing‑sucking proboscis folded beneath the head, not visible without magnification.
- Exuviae: Shed skins retain the previous instar’s coloration and size, often found near hiding places; they appear as empty, translucent shells with faint leg outlines.
The overall silhouette remains consistent across stages: a flattened, bean‑shaped outline without visible wings or cerci. Color intensifies and size increases with each molt, providing a reliable visual cue for identifying the developmental stage of a living nymph.