What do a bedbug and its larvae look like? - briefly
Adult bedbugs are tiny (4–5 mm), oval, reddish‑brown insects that lie flat when unfed and become swollen and brighter after a blood meal. Their immature stages are pale, translucent nymphs that look like miniature adults and darken with each successive molt.
What do a bedbug and its larvae look like? - in detail
The adult Cimex lectularius is a flattened, oval insect measuring 4–5 mm in length. Its body is reddish‑brown, becoming paler after a blood meal. The dorsal surface is covered with fine, hair‑like setae and a distinct, smooth exoskeleton. Six legs extend from the thorax, each ending in a claw that aids in clinging to fabric. Antennae consist of four segments, and the head bears a pair of elongated, pointed rostrums used for piercing skin. The wings are absent; instead, the thorax is broad, allowing the bug to glide beneath mattress seams and upholstery.
Immature stages, commonly referred to as nymphs, undergo five molts before reaching adulthood. Each instar resembles the adult in shape but is progressively smaller, ranging from 1.5 mm in the first stage to about 4 mm in the fifth. Nymphal coloration is translucent or pale yellow, darkening with each blood meal and successive molt. Unlike the adult, nymphs lack fully developed genitalia and display less pronounced setae. Their legs and antennae are proportionally shorter, and the rostrum remains functional for feeding. After each feeding, the nymph’s abdomen expands noticeably, indicating engorgement.
Key visual differences between mature and immature individuals include:
- Size: adults 4–5 mm; nymphs 1.5–4 mm depending on instar.
- Color: adults reddish‑brown; nymphs light yellow to brown after feeding.
- Exoskeleton: adults possess a harder, more sclerotized cuticle; nymphs are softer and more translucent.
- Reproductive structures: present only in adults.
Understanding these morphological characteristics aids accurate identification during inspection and control efforts.