Popillia japonica vs Japanese beetle

Popillia japonica and Japanese beetle both are nouns.

Word	Noun	Adjective	Verb	Adverb
Popillia japonica	Yes	No	No	No
Japanese beetle	Yes	No	No	No

As nouns, Popillia japonica and Japanese beetle are synonyms defined as:

Popillia japonica and Japanese beetle: small metallic green and brown beetle native to eastern Asia; serious plant pest in North America

Popillia japonica (noun)	Japanese beetle (noun)
small metallic green and brown beetle native to eastern Asia; serious plant pest in North America	small metallic green and brown beetle native to eastern Asia; serious plant pest in North America