 The petioles and blades of the leaves curl, twist, and become discolored.Knowledge of curly top’s early history in the United States is limited owing to its sharing similar symptoms with other diseases and disorders.According to C. O. Townsend, George G. Hedgecock with the USDA reported that, on several occasions before 1888, he observed damaging outbreaks of a disease presumed to be curly top from garden beets in Nebraska.