Head lice revisited: in vitro standardized tests and differences in malathion formulations

The recent article "Permethrin-Resistant Human Head Lice, Pediculus capitis, and Their Treatment" by Yoon and colleagues1 contained valuable information and data, including assessment of knockdown resistance by DNA sequencing. Indeed, the study of insect control is entering a genomic era. For example, I have been investigating 2 features of the head louse that may act as targets for future treatments, namely, the bacterial symbionts within head lice (with 16S rRNA sequencing and molecular phylogenetic analysis) and the glue extruded from the louse (which after deposition upon the hair shafts, oxidizes within seconds and becomes the nit sheath).2 In terms of the sheath, it is composed of 4 major bands of protein with some cross-linking to aliphatic components.2