On Dec. 11, 1919, the town of Enterprise, Alabama, dedicated a monument--to the boll weevil. A USDA photo is here, along with the following explanation: "After the boll weevil destroyed (1910-15) the area's cotton, diversified farming was begun. In gratitude for the resulting prosperity, the city erected a monument to the boll weevil in 1919."
Fuller article, with a newer picture, here.
Lyrics to "Ballad of the Boll Weevil" ("Just a-lookin' for a home") here.