RESUMO: Spumacinctus gen. nov. is described as a new saltatorial genus of Scirtidae, comprising three species: Spumacinctus mindu gen. et sp. nov., and Spumacinctus porcicaudalis gen. et sp. nov. from the Brazilian Amazon, and Spumacinctus championi (Picado, 1912) comb. nov., a species previously placed in Scirtes Illiger, 1807 from Costa Rica. We also describe the last instar larvae of the two new species, obtained by rearing larvae in laboratory conditions to produce both male and female adults. Bionomic observations are also provided, including a peculiar mode of pupation in which the pupa is surrounded by foam. An identification key (adults and larvae) to the saltatorial genera of Scirtidae from the Neotropical region is also presented.