How do lice mate? - briefly
Male head lice locate a receptive female by tactile cues, climb onto her thorax, and align their abdomens to transfer sperm directly through the genital opening. Fertilization is internal, after which the female begins laying eggs within a few days.
How do lice mate? - in detail
Lice are obligate ectoparasites that reproduce sexually. Males and females possess distinct genital structures; the male’s aedeagus and the female’s ovipositor are adapted for direct sperm transfer. Reproductive activity occurs on the host’s body surface, where both sexes remain firmly attached to hairs or skin.
Mating proceeds through the following sequence:
- Locating a partner: Males detect females by chemical cues released from the female’s cuticle and by tactile signals transmitted through the host’s hair.
- Approach and mounting: The male climbs onto the female from the dorsal side, aligns his abdomen with the posterior region of the female’s body, and secures his grip with his forelegs.
- Genital coupling: The aedeagus is inserted into the female’s genital opening. Sperm are transferred in a single ejaculate; no spermatophore is produced.
- Sperm storage: The female retains sperm in a spermatheca, allowing fertilization of multiple eggs over several days without additional copulations.
- Separation: After a copulation period ranging from a few minutes to half an hour, the pair disengages and resumes feeding.
Following insemination, the female lays eggs (nits) at intervals of 1–2 days. Each egg is cemented to a hair shaft near the scalp, typically within 1 mm of the skin. The embryonic development period lasts 7–10 days, after which the nymph hatches and begins feeding immediately. A single female can produce 30–50 eggs during her lifespan of approximately 30 days, resulting in rapid population growth under favorable conditions.
Environmental factors such as temperature and host grooming behavior influence mating frequency and egg viability. Higher temperatures accelerate developmental rates, while frequent removal of nits by the host reduces reproductive success. The combination of direct sperm transfer, internal sperm storage, and continuous egg deposition defines the efficient reproductive strategy of lice.