"leave quickly," by 1956, perhaps from bugger off (see bugger (v.)), which chiefly is British (by 1920s) but was picked up in U.S. Air Force slang in the Korean War. Also see bug (v.3). To bug out "leave quickly, scram" is from 1953.
buffo
buffoon
buffoonery
Bufo
bug
bug off
bugaboo
bugbear
bug-bite
bugger
buggery