type of beetle or larva, 1865, Southern U.S. dialect; see doodle + bug (n.). The same word was applied 1944 in R.A.F. slang to German V-model flying bombs.
Entries linking to doodle-bug
doodle v.
"scrawl aimlessly," 1935, perhaps from dialectal doodle, dudle "fritter away time, trifle," or associated with dawdle (which might be the source of the dialect word). It also was a noun meaning "simple fellow" from 1620s.
LONGFELLOW: That's a name we made up back home for people who make foolish designs on paper when they're thinking. It's called doodling. Almost everybody's a doodler. Did you ever see a scratch pad in a telephone booth? People draw the most idiotic pictures when they're thinking. Dr. Von Holler, here, could probably think up a long name for it, because he doodles all the time. ["Mr. Deeds Goes to Town," screenplay by Robert Riskin, 1936; based on "Opera Hat," serialized in American Magazine beginning May 1935, by Clarence Aldington Kelland]
Related: Doodled; Doodling.
Doodle Sack. A bagpipe. Dutch. — Also the private parts of a woman. ["Classical Dictionary of the Vulgar Tongue," 1796]
bug n.
"insect, beetle," 1620s (earliest reference is to bedbugs), of unknown origin, probably (but not certainly) from or influenced by Middle English bugge "something frightening, scarecrow" (late 14c.), a word or meaning that has become obsolete since the "insect" sense arose, except in bugbear (1570s) and bugaboo (q.v.).
The Middle English word probably is connected with Scottish bogill "goblin, bugbear," or obsolete Welsh bwg "ghost, goblin" (compare Welsh bwgwl "threat," earlier "fear," Middle Irish bocanách "supernatural being"). Some speculate that these words are from a root meaning "goat" (see buck (n.1)) and represent originally a goat-like specter. Compare also bogey (n.1) and Puck. Middle English Compendium compares Low German bögge, böggel-mann "goblin." The sense shift perhaps was by influence of Old English -budda, used in compounds for "beetle" (compare Low German budde "louse, grub," Middle Low German buddech "thick, swollen").
The name of bug is given in a secondary sense to insects considered as an object of disgust and horror, and in modern English is appropriated to the noisome inhabitants of our beds, but in America is used as the general appellation of the beetle tribe .... A similar application of the word signifying an object dread to creeping things is very common. [Hensleigh Wedgwood, "A Dictionary of English Etymology," 1859]
The meaning "defect in a machine" (1889) may have been coined c. 1878 by Thomas Edison (perhaps with the notion of an insect getting into the works). In compounds, the meaning "person obsessed by an idea" (as in firebug "arsonist") is from 1841, perhaps from notion of persistence. The colloquial sense of "microbe, germ" is from 1919.
Bugs "crazy" is from c. 1900. Bug juice as a slang name for drink is from 1869, originally "bad whiskey." The 1811 slang dictionary has bug-hunter "an upholsterer." Bug-word "word or words meant to irritate and vex" is from 1560s.