What are corpse lice? - briefly
Corpse lice are tiny, wingless insects that colonize dead or decomposing bodies, consuming tissue and bodily fluids. They differ from head and body lice and are frequently noted in forensic examinations of human remains.
What are corpse lice? - in detail
Corpse lice, scientifically known as Pthirus pubis when referring to the human pubic louse, are a distinct species of ectoparasite that colonize the hair of dead bodies. Unlike the more common head louse (Pediculus humanus capitis), they prefer coarse body hair and are adapted to feed exclusively on human blood. Their life cycle comprises three stages: egg (nit), nymph, and adult. Eggs are cemented to hair shafts and hatch after 6–10 days; nymphs undergo two molts over 10–14 days before reaching maturity. Adult females lay 6–10 eggs per day, sustaining a rapid population increase under favorable conditions.
Morphologically, corpse lice are small, flattened insects measuring 1–2 mm in length. Their bodies are broader than those of head lice, with a crab‑like appearance caused by short, robust legs that enable clinging to thick hair. Mouthparts are specialized for piercing skin and extracting blood, leading to localized itching, erythema, and secondary bacterial infection if the host is alive.
Ecologically, these parasites are obligate human parasites; they do not survive long without a host. In a deceased individual, the lack of blood flow and rising body temperature cause the insects to die within a few days. However, their presence on a corpse can provide forensic investigators with valuable information about post‑mortem interval, body handling, and possible contact with living individuals prior to death.
Forensic relevance includes:
- Estimating time since death by assessing the developmental stage of the lice.
- Determining whether the body was moved, based on the distribution of lice on different body regions.
- Inferring recent sexual contact or close personal interaction, since transmission typically occurs through direct contact.
Control measures focus on eliminating infestations in living populations through topical insecticides (permethrin, pyrethrins) and thorough washing of clothing and bedding at temperatures exceeding 50 °C. In a forensic context, preservation of lice specimens involves careful collection in ethanol for morphological or molecular analysis.