What does a louse and a clothing louse look like? - briefly
A head louse is a small, wingless insect about 2–3 mm long, with a flattened, elongated body, six legs ending in clawed tarsal segments, and a grayish‑brown coloration; its head is broader than its thorax and it clings tightly to hair shafts. A clothing (body) louse is similar in size but has a slightly longer, more robust body, a darker reddish‑brown hue, and its legs are adapted for walking on fabric rather than grasping hair.
What does a louse and a clothing louse look like? - in detail
The human head louse (Pediculus humanus capitis) is a small, wingless insect measuring 2–3 mm in length. Its body is elongated, dorsoventrally flattened, and covered with fine, translucent hairs that give a slightly mottled appearance. The head is rounded, bearing a pair of short antennae and six legs, each ending in claw‑like tarsi adapted for grasping hair shafts. The abdomen is segmented, typically gray‑brown, and may appear slightly darker after a blood meal. Eyes are reduced to simple ocelli, and the mouthparts form a piercing‑sucking stylet used to feed on scalp blood.
The body louse (Pediculus humanus humanus), also called the clothing louse, is larger, ranging from 2.5 to 4 mm. Its body is broader and more robust than that of the head louse, with a darker brown to reddish‑black coloration. The thorax bears three pairs of legs similar to the head louse, but the legs are proportionally longer, facilitating movement through fabric fibers. The abdomen is convex and may show a distinct, darker posterior segment. Antennae are shorter, and the head is less rounded, presenting a more blunt shape. The mouthparts are likewise adapted for blood feeding, but the body louse typically feeds less frequently, surviving several days between meals.
Key morphological differences:
- Size: head louse 2–3 mm; body louse 2.5–4 mm.
- Body shape: head louse slender and flattened; body louse broader and convex.
- Color: head louse gray‑brown, often translucent; body louse darker brown to reddish‑black.
- Leg length: body louse legs relatively longer, suited for fabric navigation.
- Habitat adaptation: head louse claws optimized for grasping hair; body louse claws adapted to cling to clothing fibers.
Both species possess a three‑segmented thorax, compound eyes reduced to simple ocelli, and a ventral sucking apparatus, but their external morphology reflects distinct ecological niches—scalp hair versus sewn garments.