gadfly vs warble fly

gadfly and warble fly both are nouns.

Word	Noun	Adjective	Verb	Adverb
gadfly	Yes	No	No	No
warble fly	Yes	No	No	No

As nouns, warble fly is a hyponym of gadfly; that is, warble fly is a word with a more specific, narrower meaning than gadfly:

gadfly: any of various large flies that annoy livestock
warble fly: hairy bee-like fly whose larvae produce lumpy abscesses (warbles) under the skin of cattle

Other hyponyms of gadfly include botfly, cleg, clegg, horse fly, horsefly.

gadfly (noun)	warble fly (noun)
any of various large flies that annoy livestock	hairy bee-like fly whose larvae produce lumpy abscesses (warbles) under the skin of cattle
a persistently annoying person