The ceresine treehopper Stictolobus minutus (Funkhouser), described by Thomas Say in 1830 as Membracis subulata (a junior primary homonym), is seldom collected; museum specimens typically are represented by singletons. In July 2016, nymphs of S. minutus were discovered on big bluestem (Andropogon gerardii Vitman; Poaceae) in the Buck Creek Serpentine Barrens of western North Carolina. This bunchgrass was sampled periodically in 2016, 2017, and 2019, and weekly in 2018, by using an ax handle to strike basal stems and crowns, and collecting dislodged nymphs and adults from an enamel pan or net bag placed at the base of plants. First instars appeared as early as 1 June, with the first adult, a male, found on 8 July. A fifth instar was taken as late as 12 August. Adults of this univoltine species typically were not observed on big bluestem after early August, perhaps having dispersed to woody plants for oviposition. Late instars also were collected from little bluestem (Schizachyrium scoparium [Michx.] Nash) in 2018 and 2019. The presence of all five instars in crowns of big bluestem devoid of small forbs, coupled with a review of treehopper-grass associations, suggests that S. minutus might be the first North American membracid known to specialize on Poaceae. The adult is diagnosed and described; color images of the adult male, female, male genitalia, and all nymphal instars are provided.