Pthirus

Pthirus
Pthirus gorillae
Pthirus pubis
Scientific classification Edit this classification
Kingdom: Animalia
Phylum: Arthropoda
Clade: Pancrustacea
Class: Insecta
Order: Psocodea
Suborder: Troctomorpha
Infraorder: Phthiraptera
Parvorder: Anoplura
Family: Pthiridae
Ewing, 1929
Genus: Pthirus
Leach, 1815
Type species
Pediculus pubis
Species
Synonyms
  • Phthirus Leach, 1817

Pthirus is a genus of lice. There are only two extant species, and they are the sole known members of the family Pthiridae. Pthirus gorillae infests gorillas, and Pthirus pubis afflicts humans, and is commonly known as the crab louse or pubic louse. The two species diverged some 3.3 million years ago.

Since 1958 the generic name Pthirus has been spelled with pth rather than phth, despite this being based on a misspelling of the Greek-derived phthirus.

A three-gene phylogeny (largely reproduced in a later phylogenomic analysis, which included fewer taxa of this genus) is:

Polyplax serrata

Pediculus humanus capitis

Pediculus humanus humanus

0.8

Pediculus schaeffi

5.9

Pthirus pubis

Pthirus gorillae

2.9
16.2

Pedicinus hamadryas

Pedicinus badii

Pedicinus pictus

4.3
17.2
27.4
47.6

Labels below nodes are estimated divergence times (Mya).