June bug vs figeater

June bug and figeater both are nouns.

Word	Noun	Adjective	Verb	Adverb
June bug	Yes	No	No	No
figeater	Yes	No	No	No

As nouns, figeater is a hyponym of June bug; that is, figeater is a word with a more specific, narrower meaning than June bug:

June bug: any of various large usually brown North American leaf-eating beetles common in late spring; the larvae feed on roots of grasses etc.
figeater: large greenish June beetle of southern United States

Other hyponyms of June bug include green June beetle.

June bug (noun)	figeater (noun)
any of various large usually brown North American leaf-eating beetles common in late spring; the larvae feed on roots of grasses etc.	large greenish June beetle of southern United States