Where do lice live and reproduce? - briefly
Lice reside on the hair, fur, or feathers of their hosts, attaching their eggs (nits) to the strands near the scalp or skin. Their complete life cycle—egg, nymph, adult—develops on the host, relying on direct contact for reproduction.
Where do lice live and reproduce? - in detail
Lice are obligate ectoparasites that complete their entire life cycle on a host or in the immediate surroundings created by the host.
Head‑feeding lice (Pediculus humanus capitis) reside on the scalp, attaching their claws to hair shafts. They lay eggs (nits) on the hair close to the scalp, where temperature remains around 33 °C.
Body‑feeding lice (Pediculus humanus corporis) inhabit clothing seams and the skin beneath garments. Females deposit nits on fabric fibers; larvae migrate to the host’s body for feeding.
Pubic lice (Pthirus pubis) colonize coarse hair in the genital region, perianal area, and occasionally chest or facial hair. Eggs are glued to hair shafts near the skin surface.
Reproductive cycle:
- Egg (nit): Female lays 5–10 eggs per day; incubation lasts 7–10 days at typical human body temperature.
- Nymph: Hatch into a six‑stage immature form. Each stage lasts 1–2 days, requiring a blood meal before molting.
- Adult: After the final molt, the adult lives 30–45 days on the host, feeding several times daily. Females become sexually mature within 3–5 days and resume oviposition.
Environmental constraints:
- Minimum relative humidity of 30 % is required for egg viability; excessive dryness leads to desiccation.
- Temperatures below 20 °C slow development; above 35 °C increase mortality.
- Absence of a host for more than 48 hours results in death of nymphs and adults, though eggs may survive up to a week.
Transmission occurs through direct contact with infested hair or clothing, or via contaminated garments, bedding, or towels that retain viable eggs. Control measures target both the adult insects and the attached eggs, as nits remain attached to hair or fibers until they hatch.