CreatureData

Crab louse

Pthirus pubis (Linnaeus, 1758)

Status not recordedinsects

The crab louse (Pthirus pubis) is an insect in the family Pthiridae, which belongs to the suborder Troctomorpha of the order Psocodea. Other English names for the crab louse are Crab-louse, Pubic louse and Human pubic louse.

Crab louse (Pthirus pubis)
Photo: Credit at source · Public domain · Wikimedia Commons

Quick facts about the crab louse

Its scientific name carries the authority (Linnaeus, 1758), and it is placed in the genus Pthirus, class Insecta and phylum Arthropoda. The Catalogue of Life lists the crab louse as living, not extinct.

Weight
Not recorded
Length
1.3 mm – 2 mmsrc for Length
Lifespan
Not recorded
Main food
Not recorded
Habitat
Not recorded
Egg incubation
6 days – 8 dayssrc for Egg incubation
Young per litter or clutch
Not recorded
Reproduction
Eggssrc for Reproduction
Conservation status
Not recorded
Countries on record
Not recorded

How big is the crab louse?

CRAB LOUSE · LENGTH 2 MMADULT HUMAN · HEIGHT 1.7 M
At 2 mm, the recorded maximum length of the crab louse is about 0.1% of the height of an adult human (1.7 m, a fixed reference used for scale).

Photos of the crab louse

Only freely licensed photos are shown. Each carries its creator and licence.

Crab louse (Pthirus pubis)
Ed Uthman from Houston, TX, USA · CC BY 2.0 · Wikimedia Commons
Crab louse (Pthirus pubis)
Jbjensen1 · CC BY 4.0 · Wikimedia Commons
Crab louse (Pthirus pubis)
Laboratoires Servier · CC BY-SA 3.0 · Wikimedia Commons
Crab louse (Pthirus pubis)
Centers for Disease Control and Prevention · Public domain · Wikimedia Commons

Where does the crab louse live?

Not recorded

Where has it been introduced?

Also listed for parts of: United States (Hawaii).

Introduced means brought by people and now present; invasive means the country's checklist records an impact. A species can be native to one part of a country and introduced in another. Source: Global Register of Introduced and Invasive Species (CC BY 4.0).

What is the crab louse?

Quoted from WikipediaCC BY-SA 4.0

The crab louse or pubic louse (Pthirus pubis) is an insect that is an obligate ectoparasite of humans, feeding exclusively on blood. The crab louse usually is found in the person's pubic hair. Although the louse cannot jump, it can also live in other areas of the body that are covered with coarse hair, such as the perianal area, the general body hair, and the eyelashes (in children).

Humans are the only known hosts of the crab louse, although a closely related species, Pthirus gorillae, infects gorillas. The human parasite is thought to have diverged from Pthirus gorillae approximately 3.3 million years ago. It is more distantly related to the genus Pediculus, which contains the human head and body lice and lice that affect chimpanzees and bonobos.

From the Wikipedia article “Crab louse” (en.wikipedia.org/w/index.php?title=Crab_louse&oldid=1337571889), by Wikipedia contributors, licensed under CC BY-SA 4.0 (creativecommons.org/licenses/by-sa/4.0). This block is kept separate from our own text.

Is the crab louse endangered?

No conservation assessment is recorded for this species in our sources. That is not the same as being safe: it has not been matched to an assessment.

How is the crab louse classified?

  1. kingdomAnimalia
  2. phylumArthropoda
  3. classInsecta
  4. orderPsocodea
  5. familyPthiridae
  6. genusPthirus
  7. SpeciesPthirus pubis (Linnaeus, 1758)

Synonyms Pediculus ferus, Pediculus pubis, Phthirus chavesi, Phthirus pubis, Pthirus inguinalis, Pthirus inquinalis

Other names and names in other languages (24)
  • Crab-louseEnglish
  • Human pubic louseEnglish
  • Pubic louseEnglish
  • pioyu púbicuAsturian
  • veš muňkaCzech
  • FladlusDanish
  • FilzlausGerman
  • LadillaSpanish
  • satiainenFinnish
  • MorpionFrench
  • Pou du pubisFrench
  • PiattolaItalian
  • Pidocchio del pubeItalian
  • ケジラミJapanese
  • 사면발이Korean
  • PlatluisDutch
  • SchaamluisDutch
  • Wesz łonowaPolish
  • Лобковая вошьRussian
  • voš lonováSlovak
  • flatlusSwedish
  • Kasık bitiTurkish
  • İnsan Kasık BitiTurkish
  • 陰蝨Chinese

Catalogue of LifeWikipediaiNaturalistITISTAXREFWikidataWoRMS

Relatives of the crab louse

Other species in the same genus Pthirus.

CompareCrab louse vs Gorilla louse

Common questions

Each answer is written from the sourced facts on this page, and only where they hold the answer.

What kind of animal is the crab louse?

The crab louse is an insect. It belongs to the family Pthiridae in the order Psocodea.

What is the scientific name of the crab louse?

The scientific name of the crab louse is Pthirus pubis, in the genus Pthirus.

What are other names for the crab louse?

The crab louse is also called Crab-louse, Pubic louse and Human pubic louse.

Who named the crab louse and when?

The crab louse was named by Linnaeus in 1758, written as (Linnaeus, 1758).

Is the crab louse extinct?

No. The Catalogue of Life lists the crab louse as living, not extinct.

What phylum and class does the crab louse belong to?

The crab louse belongs to the phylum Arthropoda and the class Insecta.

Sources and how to cite this page

Data as of 2026-11-14. How this page is put together.

Embed a card for this animal on your own site

Copy this code. The card shows the photo with its credit, key facts and a link back to this page.

Preview the card

APA

CreatureData. (2026). Crab louse (Pthirus pubis). Retrieved from https://creaturedata.com/animals/crab-louse

MLA

“Crab louse (Pthirus pubis).” CreatureData, 2026, https://creaturedata.com/animals/crab-louse.

BibTeX
@misc{crab_louse_2026,
  title = {Crab louse (Pthirus pubis)},
  author = {{CreatureData}},
  year = {2026},
  url = {https://creaturedata.com/animals/crab-louse},
  note = {Data as of 2026-11-14}
}