What is a moose louse? - briefly
«The moose louse (genus Trichodectes) is a permanent ectoparasite that feeds on the skin and hair of moose, causing irritation and potential secondary infections.» «Transmission occurs through direct contact among individuals, especially during the rutting season.»
What is a moose louse? - in detail
The moose louse, Trichodectes melesinus, is a chewing louse that inhabits the pelage of Alces alces. It belongs to the order Phthiraptera, family Trichodectidae. Adult specimens measure 2–3 mm, possess a dorsoventrally flattened body, and lack wings. Mouthparts are adapted for chewing epidermal debris and skin scales rather than blood extraction.
Reproduction occurs year‑round. Females lay 2–3 eggs (nits) on hair shafts; each egg hatches in 5–7 days. Nymphal development comprises three instars, each lasting approximately 5 days. The complete life cycle, from egg to adult, is completed within 3 weeks under optimal temperature (≈20 °C). Population density peaks during the host’s summer molt when new hair provides abundant attachment sites.
Ecological aspects:
- Primary host: moose; occasional records on elk and reindeer.
- Geographic range: boreal and subarctic forests of North America, northern Europe, and Siberia.
- Habitat preference: dense, moist fur zones such as the neck, back, and flanks.
- Transmission: direct contact during social grooming, mating, or mother‑calf interactions.
Impact on the host includes:
- Mechanical irritation leading to excessive scratching.
- Localized hair loss and skin thickening (hyperkeratosis).
- Secondary bacterial infection risk when skin integrity is compromised.
Management strategies focus on reducing infestation intensity:
- Regular inspection of fur, especially during spring and autumn.
- Application of topical insecticides (e.g., permethrin‑based formulations) following veterinary guidelines.
- Environmental control is limited, as the louse completes its life cycle on the host.
Research indicates that heavy infestations may affect thermoregulation, but mortality directly attributable to the parasite is rare. Continuous monitoring of herd health provides early detection and limits population buildup.