Doryphoros is Greek for “spear-bearer.”
The Doryphoros is a Greek statue of a soldier, much prized and copied by the Romans (one of the best examples was found in Pompeii). Sculpted by Polykleitos as part of his “canon,” it was a study in the ideal proportions of a man and is considered as a perfection of the form.
One American folk term for the Colorado potato beetle was the “ten-striped spearman.” The beetle made its way to Europe, where it was a huge pest after World War I, almost wiping out the French potato crop. (The US was accused by several countries of having purposely introducing the pest purposefully.) The French called it a doryphore, because it was once in the genus doryphora decemlineata (“ten lines”; its name is different now).
In World War II, doryphore became a French slang epithet for German soldiers, who similarly landed like a plague and ate all the potatoes. Schoolchildren were recruited to help carry out a campaign to wipe out the beetle, and carried signs saying MORT AUX DORYPHORES! which amused the French greatly.
Doryphore was also the name a a prototype combat biplane made by LACAB for the Belgian Air Force in 1934. Here’s a postcard from 1935 mentioning “Le doryphore de la pomme de terre menace l’agriculture et l’horticulture.” Clearly, the word had currency in Europe.
(Interestingly, in Russia and the Ukraine the beetle was called kolorady, and in Ukraine that name became “a derogatory term to describe pro-Russian separatists [due to the] black and orange stripes on so-called St. George’s ribbons worn by many of the separatists.”)
The English writer and diplomant Harold Nicolson (husband of Vita Sackville-West) coined the term “doryphore” in 1949:
These Colorado beetles will spent hours searching for a misprint in the Oxford English Dictionary… Although these doryphores may achieve the short delight of proving that an author has made a mistake on page 479, they will never know the slow, long pleasure of writing a large book with continuous application.
Nicolson has the first four cites in the OED, but others used it, including Herb Caen and the editors of the New Yorker (in 1950).
Anyway, after all that fun I can’t find a definitive reason someone called the beetle a spearman, or why Nicolson used the word figuratively. Were copyediting pedants really such a plague that they deserved to be compared to potato bugs or German soldiers?