pubic louse vs Phthirius pubis

pubic louse and Phthirius pubis both are nouns.

Word	Noun	Adjective	Verb	Adverb
pubic louse	Yes	No	No	No
Phthirius pubis	Yes	No	No	No

As nouns, pubic louse and Phthirius pubis are synonyms defined as:

pubic louse and Phthirius pubis: a louse that infests the pubic region of the human body

Other synonyms of pubic louse include crab, crab louse.

pubic louse (noun)	Phthirius pubis (noun)
a louse that infests the pubic region of the human body	a louse that infests the pubic region of the human body