body louse vs Pediculus corporis

body louse and Pediculus corporis both are nouns.

Word	Noun	Adjective	Verb	Adverb
body louse	Yes	No	No	No
Pediculus corporis	Yes	No	No	No

As nouns, body louse and Pediculus corporis are synonyms defined as:

body louse and Pediculus corporis: a parasitic louse that infests the body of human beings

Other synonyms of body louse include cootie.

body louse (noun)	Pediculus corporis (noun)
a parasitic louse that infests the body of human beings	a parasitic louse that infests the body of human beings