Green’s Dictionary of Slang

1. (US) a (heavy) smoker.

1860

Burlington Free Press (VT) 13 Feb. 2/5: Fetid breath forever, / Saturated clothes / [...] / Maidens when you marry, / Tobacco worms don’t take; / Think not Dick or Harry / Will quit it for your sake!

2. (US) a person from Virginia [the state known for its tobacco crops].

1865		in B.L. Ridley Battles and Sketches of the Army of Tennessee (1906) 460: The North Carolinians are called ‘Tar Heels’ [...] Virginians, ‘Tobbacco [sic] Worms.’.
1868		Galveston Dly News (TX) 14 Feb. 3/4: The editor of the Nativbe Virfginian doesnt seem to be smitten with [...] the Virginia Convention. He says: ‘Very little space in these columns has been [...] devoted to the doings of the assemblage of [...] yaller-jackets, black gnats, tobacco-worms, wood-lice, back-snappers [...] and pismires, which now defile out ancient capitol’.