Use of human lice in forensic entomology.

Hematophagus arthropod bloodmeals may be useful in identifying individual hosts. To examine the application of human lice as a forensic tool, that is, as evidence of physical contact between individuals, body lice from a laboratory colony and head lice, collected from the head of infested children, were studied. The DNA profile of an individual was detectable in the pooled bloodmeals of two body lice, up to 20 h postfeeding. A mixed DNA profile of two hosts was identifiable in the pooled bloodmeals of three lice, for 3 h postfeeding. By pooling the bloodmeals of three adult and three nymphal head lice, a mixed DNA profile was obtained. These results indicate that, in criminal cases where there has been close contact between assailant and victim, louse bloodmeals should not be overlooked as potentially critical evidence.