Etymology From Middle English blewbothel, from blew (“blue”) + bothel (“flower in the Asteraceae family”). In sense 2, a shortening of bluebottle fly. The fly was so named because it resembles the bluebottle flower in colour. The other transferred senses likewise have reference to the colour of the respective referents.
1
A cornflower, a plant that grows in grain fields, Centaurea cyanus.
2
Any of various blowflies of the genus Calliphora that have an iridescent metallic-blue body and make a loud buzzing noise when flying.
The flies that troubled me most were a large kind of blue-bottle or blow-fly. These settled in swarms on my bird skins when first put out to dry, filling their plumage with masses of eggs, which, if neglected, the next day produced maggots.1869, Alfred Russel Wallace, The Malay Archipelago, volume II, London: Macmillan and Co., page 329:
The incredibly long body as well as the extended wings were of a gleaming purplish-gray colour: I can only liken it to that of a meat fly or common "bluebottle".1930, Sax Rohmer, The Day the World Ended, published 1969, page i. 16:
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He could imagine the dead blue-bottles being hastily swept out for the summer let and the stale rooms briefly aired by a cleaning woman sent by the estate agent in Royale.1953, Ian Fleming, “The Crawling of the Skin”, in Casino Royale, London: Pan Books, published 1955, page 113:
3
A blue ant, Diamma bicolor, a parasitic wasp native to Australia.
4
Any of various large papilionid butterflies of the genus Graphium, also called triangles, etc.
I will have you as soundly swing’d for this, you bluebottle rogue!c. 1596–1599 (date written), William Shakespeare, “The Second Part of Henry the Fourth, […]. Epilogue.”, in Mr. William Shakespeares Comedies, Histories, & Tragedies […] (First Folio), London: […] Isaac Iaggard, and Ed[ward] Blount, published 1623, →OCLC, [Act V, scene vi]:
[…] comic writers […] have never failed to make capital out of the New Police, Peel's Raw-Lobsters, Peelers, Blue Bottles, &c., &c.1878, Charles Hindley, The life and times of James Catnach, page 206:
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COOMBE: He got the clinch only last week — eighteen months. You see it's no good having anybody here as ain't got a^([sic]) unblemished character. We don't want to have the bluebottles come sniffing round here, do we?1882, Henry Herman, Henry Arthur Jones, The Silver King:
To-morrow there is a party of purple at the “blue” Miss Berry’s. Shall I go? um! — I don’t much affect your blue-bottles ; — but one ought to be civil.1813, Lord G. G. Byron, edited by Rowland E. Prothero, The Works Of Lord Byron Letters And Journals Vol II, page 358:
There appears to be a growing disposition on the part of the literary and dramatic blue-bottles of this city to get up a national drama and to manufacture a new race of actors.1846 February 22, “Letter from Spranger Barry, Esq.”, in Sunday Dispatch (New York), page 2, Column 6:
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..and did not the rich dowager-countess Bluebottle marry her footman, who forthwith became a lord and was made a privy counsellor.1853 January 29, Geo. F. Pardon, “Common People”, in The Working Man’s Friend, page 282:
Etymology From blue + bottle, in reference to the creature's bottle-like bladder.
1
A marine jellyfish of the genus Physalia, which includes Physalia physalis, the Portuguese man-of-war, and Physalia utriculus, the Pacific man-of-war; a man-of-war.