In

…subspecies,Pediculus humanus capitis, the head louse, andP. humanus humanus, the body louse, or cootie.

…insecticidal shampoos for control, the head louse has developed resistance to many insecticides and is exhibiting a resurgence in many areas of the world. Heavy infestations of lice may cause intense skin irritation, and scratching for relief may lead to secondary infections. In domestic animals, rubbing and damage to hides…

…names, depending on whether the head louse is considered as a distinct species or as a variety or subspecies of the body louse. At present they are probably best referred to under one name,Pediculus humanus, but if separated subspecifically they must be calledPediculus humanus humanus (the body louse)…