bluebottle vs blow fly

bluebottle and blow fly both are nouns.

Word	Noun	Adjective	Verb	Adverb
bluebottle	Yes	No	No	No
blow fly	Yes	No	No	No

As nouns, blow fly is a hypernym of bluebottle; that is, blow fly is a word with a broader meaning than bluebottle:

bluebottle: blowfly with iridescent blue body; makes a loud buzzing noise in flight
blow fly: large usually hairy metallic blue or green fly; lays eggs in carrion or dung or wounds

Other hypernyms of bluebottle include blowfly.

bluebottle (noun)	blow fly (noun)
blowfly with iridescent blue body; makes a loud buzzing noise in flight	large usually hairy metallic blue or green fly; lays eggs in carrion or dung or wounds
an annual Eurasian plant cultivated in North America having showy heads of blue or purple or pink or white flowers