May bug vs May beetle

May bug and May beetle both are nouns.

Word	Noun	Adjective	Verb	Adverb
May bug	Yes	No	No	No
May beetle	Yes	No	No	No

As nouns, May bug and May beetle are synonyms defined as:

May bug and May beetle: any of various large European beetles destructive to vegetation as both larvae and adult

Other synonyms of May bug include cockchafer, Melolontha melolontha.

As nouns, May bug and May beetle are synonyms defined as:

May bug and May beetle: any of various large usually brown North American leaf-eating beetles common in late spring; the larvae feed on roots of grasses etc.

Other synonyms of May bug include June beetle, June bug.

May bug (noun)	May beetle (noun)
any of various large European beetles destructive to vegetation as both larvae and adult	any of various large European beetles destructive to vegetation as both larvae and adult
any of various large usually brown North American leaf-eating beetles common in late spring; the larvae feed on roots of grasses etc.	any of various large usually brown North American leaf-eating beetles common in late spring; the larvae feed on roots of grasses etc.