Pthiridae

Definition

A family of sucking lice (order Psocodea) comprising the single genus Pthirus. The family contains only two extant species: Pthirus pubis, the crab or pubic louse of humans, and Pthirus gorillae, a parasite of gorillas. Members are distinguished by their broad, crab-like body form and relatively short antennae compared to other sucking lice, with claws adapted for grasping coarse body hair.

Etymology

From the genus name Pthirus + -idae (family suffix).

Example

Molecular dating suggests Pthirus gorillae and P. pubis diverged approximately 3.3 million years ago, roughly coinciding with the divergence of their respective hominoid hosts.

Related Terms

• Pthirus
• Phthiraptera
• Psocodea
• Pediculidae
• crab louse
• Sucking lice
• Ectoparasite

Usage Notes

Sometimes misspelled 'Phthiridae' with an added 'h'. The family is morphologically and ecologically distinct from Pediculidae (head and body lice), with Pthiridae species showing greater host specificity and more specialized claw morphology for gripping pubic or coarse body hair rather than scalp hair.