E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
B Flats.
Bugs. The pun is B (the initial letter), and flat, from the flatness of the obnoxious insect. Also called Norfolk Howards, from Mr. Bugg, who advertised in the Times that he should in future change his name into Norfolk Howard. (See F SHARP.)