What does a male louse look like?

What does a male louse look like? - briefly

Male head lice are slightly smaller than females, with a broader, blunt abdomen and no egg‑carrying shape. They have three pairs of legs, a pair of antennae, and a translucent yellowish body.

What does a male louse look like? - in detail

Male head lice are small, wingless insects measuring approximately 2 mm in length, slightly shorter than females that average 2.5–3 mm. Their bodies are elongated and flattened, facilitating movement through hair shafts. The dorsal surface is typically gray‑brown, sometimes appearing translucent when unfed; after a blood meal the abdomen darkens to a reddish hue.

The head region bears a pair of short, segmented antennae, each composed of five antennomeres. Compound eyes are absent, but the head bears a pair of simple eyespots (ocelli) that detect light intensity. Mouthparts form a piercing‑sucking stylet used to ingest blood.

The thorax consists of three distinct segments, each bearing a pair of legs. Legs terminate in sharp claws that grasp hair fibers, while the tibiae feature a row of comb‑like spines (pretarsal setae) that aid in locomotion. The legs are proportionally shorter than those of the female, reflecting the male’s reduced need for extensive movement during mating.

The abdomen is segmented into seven visible tergites. In males, the terminal abdominal segment expands into a small, rounded genital capsule. The external genitalia include a pair of elongated, curved parameres and a median aedeagus that houses the reproductive organs. These structures are clearly visible under magnification and differentiate males from females, whose abdomens terminate in a broader, more rounded posterior with a visible ventral opening for egg‑laying.

Key distinguishing characteristics:

  • Size: ≈2 mm, slightly smaller than females.
  • Color: gray‑brown to translucent; abdomen reddens after feeding.
  • Antennae: five‑segmented, short.
  • Legs: three pairs, each with claw and spines; shorter than female legs.
  • Abdomen: terminal genital capsule with visible parameres and aedeagus.

These morphological traits enable reliable identification of male head lice in microscopic examinations.