Vanduzea triguttata (Burmeister) is a wide-ranging, mainly North American membracid (Smiliinae: Amastrini) whose bionomics remain little known. Fieldwork in the Nebraska Sandhills indicated that this treehopper develops on leadplant, Amorpha canescens (Fabaceae). Its ant-attended aggregations, involving four species of Formica, were observed at 18 sites in nine counties. The treehopper was at least bivoltine; first-generation adults developed in late June to early July and second-generation adults were found as late as early October. Previously recorded hosts, certain composites (Asteraceae) and legumes (Fabaceae), are reviewed. Plants likely to support nymphal development (true hosts) are distinguished from those that probably are used only for food or shelter by adults, or represent incidental occurrences. Characters of the forewing that proved useful in differentiating Nebraska specimens of V. triguttata from the morphologically similar, black locust-feeding V. arquata (Say) are presented. Vanduzea vestita Goding is proposed as a synonym of V. arquata rather than a synonym of V. triguttata.