How do genital lice look? - briefly
Genital lice are tiny, wingless insects about 1–2 mm long, with a flattened, oval body and six legs adapted for grasping hair; they are usually pale gray or brown and may appear translucent when unfed. Their nymphs look similar but are smaller and lack fully developed wings.
How do genital lice look? - in detail
Pubic lice, scientifically known as Pthirus pubis, are small, laterally flattened insects measuring 1–2 mm in length. Their bodies are broad and crab‑like, giving them a distinctive oval shape when viewed from above. The dorsal surface is covered with fine, translucent scales that can appear light brown or grayish, depending on the degree of blood engorgement.
The head bears a short, triangular antenna composed of five segments. Mouthparts are piercing‑sucking, adapted for feeding on blood. Each of the six legs ends in a pair of sharp claws, enabling the parasite to grasp coarse hair shafts typical of the pubic region. The front legs are longer than the middle and hind pairs, providing additional leverage for clinging to hair.
Color varies from pale ivory in unfed individuals to darker reddish‑brown after a blood meal. The abdomen is slightly convex, with visible segmentation but no distinct segmentation lines. Legs are pale, often matching the body hue, and the claws are transparent.
Nymphs resemble adults but are half the size and lack fully developed genitalia. They undergo three molts before reaching maturity, each stage showing incremental growth in body width and leg length. Nits (eggs) are oval, 0.5 mm long, and firmly attached to hair shafts near the base. Unhatched nits appear white or translucent; after hatching, the empty shells remain attached and may be mistaken for debris.
In contrast to head lice (Pediculus humanus capitis), which are elongated and have longer, thinner legs, pubic lice are markedly broader, with a compact, crab‑like silhouette and robust claws suited for coarse hair. This morphology facilitates rapid movement across the pubic region and enables the parasite to remain anchored during host grooming.