Prathapanius Viswajyothi & Clark, gen. nov., is described and illustrated. The genus is placed in the chrysomelid section Diabroticites Chapuis (subtribe Diabroticina Chapuis, tribe Luperini Chapuis, subfamily Galerucinae Latreille). It is monobasic, containing Prathapanius fortis Viswajyothi & Clark, sp. nov., from Ecuador. The new genus is briefly compared with Acalymma Barber, Isotes Weise, and Zischkaita Bechyné.