SHORT COMMUNICATION Evidence from Mitochondrial DNA That Head Lice and Body Lice of Humans (Phthiraptera: Pediculidae) are Conspecific

The speciÞc status of the head and body lice of humans has been debated formore than 200 yr. To clarify the speciÞc status of head and body lice, we sequenced 524 base pairs (bp) of the cytochrome oxidase I (COI) gene of 28 head and 28 body lice from nine countries. Ten haplotypes that differed by 1Ð5 bp at 11 nucleotide positions were identiÞed. A phylogeny of these sequences indicates that these head and body lice are not from reciprocallymonophyletic lineages. Indeed, head and body lice share three of the 10 haplotypes we found. FST values and exact tests of haplotype frequencies showed signiÞcant differences between head and body lice. However, the same tests also showed signiÞcant differences among lice from different countries. Indeed, more of the variation in haplotype frequencies was explained by differences among lice from different countries than by differences between head and body lice. Our results indicate the following: (1) head and body lice do not represent reciprocally monophyletic lineages and are conspeciÞc; (2) gene ßow among populations of lice from different countries is limited; and (3) frequencies of COI haplotypes can be used to study maternal gene ßow among populations of head and body lice and thus transmission of lice among their human hosts.