How does lice fertilization occur? - briefly
Male lice copulate by inserting their aedeagus into the female’s genital opening, delivering sperm directly into her oviducts. Fertilization occurs internally, after which the female deposits eggs (nits) on the host’s hair.
How does lice fertilization occur? - in detail
Lice reproduce through internal fertilization. Males possess a short, hardened aedeagus equipped with paired claspers that grip the female’s abdomen during copulation. The male mounts the female from behind, aligns the genital openings, and inserts the aedeagus into the female’s reproductive tract. Sperm are transferred directly into the spermatheca, a storage organ that can retain viable sperm for several weeks.
After mating, the female’s ovarioles produce oocytes that travel through the oviduct. As each oocyte passes the spermatheca, stored sperm are released, allowing fertilization to occur within the oviduct. The fertilized egg is then encased in a protective shell and deposited as a nit, firmly attached to hair shafts with a cement-like substance. Eggs develop over 7–10 days, depending on temperature and species, before hatching into nymphs.
Key anatomical features involved in the process include:
- Male aedeagus – hardened tube for sperm delivery, ending in a small opening.
- Claspers (cerci) – structures that secure the male to the female during mating.
- Female spermatheca – sac for sperm storage, enabling multiple fertilizations from a single copulation.
- Ovipositor – short, flexible organ that positions eggs for attachment to the host’s hair.
Mating behavior varies among species. Head lice (Pediculus humanus capitis) typically mate on the host’s scalp, with males seeking receptive females that are not yet carrying eggs. Body lice (Pediculus humanus corporis) exhibit similar mechanics but may encounter more frequent host movement, influencing copulation duration.
Sperm competition is limited because females usually mate only once or twice in their lifespan, and the spermatheca’s selective environment favors the first male’s sperm. Nonetheless, some studies report occasional remating, which can introduce additional genetic material into the egg pool.
Overall, the reproductive cycle proceeds from direct male‑female contact, through internal sperm transfer and storage, to fertilization within the female’s oviduct, culminating in the deposition of adhesive eggs that develop into the next generation.