May beetle vs May bug

May beetle and May bug both are nouns.

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

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

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

Other synonyms of May beetle include cockchafer, Melolontha melolontha.

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

May beetle and May bug: 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 beetle include June beetle, June bug.

May beetle (noun)	May bug (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.