A closer look at Pthirus pubis

Pthirus pubis, commonly referred to as the pubic louse or crab louse, and delicately designated papillon d'amour by the French, is an insect whose biology has been rather neglected in comparison with the attention lavished on the head louse and clothing louse. Even its name is frequently misspelled. The generic name was intended to be Phthirus, but as a result of a misprint, Pthirus was confirmed as the official name by the International Commission on Zoological Nomenclature.1 It has no close relatives other than a similar species found on gorillas. We present here a number of scanning electron micrographs which demonstrate some of the anatomical features of this parasite. The structure of the mouthparts is demonstrated, and the mechanism of feeding described.