How are lice bred? - briefly
Female lice attach eggs to the host’s hair shafts; the eggs hatch in 7–10 days into nymphs that mature after several molts. The complete development from egg to adult requires roughly three weeks under favorable conditions.
How are lice bred? - in detail
Lice reproduction proceeds through a predictable sequence that can be replicated under controlled conditions. Adult females deposit eggs (nits) on host hair or feathers, anchoring each egg with a cement secreted from the abdomen. Egg incubation requires temperatures between 28 °C and 32 °C and relative humidity of 70 %–90 %. Under these parameters, hatching occurs after 7–10 days.
Newly emerged nymphs resemble miniature adults but lack fully developed mouthparts. They undergo three successive molts, each lasting 3–5 days, before reaching sexual maturity. Molting demands the same temperature and humidity range; deviations prolong development or increase mortality. Adult lice feed continuously on blood, supplying the energy needed for egg production. Females can lay 5–10 eggs per day, with a total reproductive output of 100–200 eggs over a lifespan of 20–30 days.
Laboratory propagation of lice follows these steps:
- Host preparation: Secure a suitable animal (e.g., rabbit, chicken) or artificial membrane system that provides a blood source.
- Environmental control: Maintain incubators at 30 °C ± 1 °C and 80 % relative humidity; monitor with calibrated sensors.
- Egg collection: After females have laid, gently detach nits using fine forceps, avoiding damage to the operculum.
- Incubation: Place nits on a sterile substrate within the incubator; record hatching times.
- Nymph rearing: Transfer hatchlings onto the host or membrane, providing continuous access to blood. Replace the host or membrane as needed to prevent overcrowding.
- Molting observation: Inspect daily for exuviae to confirm successful molts; remove dead individuals promptly.
- Adult maintenance: Separate males from females after sexual maturation to control mating frequency if required for experimental designs.
Successful breeding depends on meticulous regulation of temperature, humidity, and host availability. Deviations in any parameter result in reduced hatch rates, delayed molting, or increased mortality, underscoring the necessity of precise environmental management.