gadfly
Pronunciation:
/ˈɡædflaɪ/noun
Definitions
Any dipterous insect of the family Oestridae, commonly known as botflies.
Synonyms:botflyA horsefly: any of various species of fly, of the family Tabanidae, noted for buzzing about animals and sucking their blood.
Synonyms:horseflystoat-flystoutOne who upsets the status quo by posing upsetting or novel questions, or attempts to stimulate innovation by proving an irritant.
One who merely irritates without making useful suggestions.