Since sequencing the human body louse genome, substantial advances have occurred in the utilization
of the information gathered from louse genomes and transcriptomes. Comparatively, the body louse genome
contains far fewer genes involved in environmental response, such as xenobiotic detoxification and innate
immune response. Additionally, the body louse maintains a primary bacterial endosymbiont, Candidatus
Riesia pediculicola, and a number of bacterial pathogens that it vectors, which have genomes that are
also reduced in size. Thus, human louse genomes offer unique information and tools for use in advanc-
ing our understanding of coevolution among vectors, endosymbionts and pathogens.
In this review, we summarize the current literature on the extent of pediculicide resistance, the avail-
ability of new pediculicides and information establishing this organism as an efficient model to study
how xenobiotic metabolism, which is involved in insecticide resistance, is induced and how insects modify
their innate immune response upon bacterial challenge resulting in enhanced vector competence.