Cyclanthura, gen. n., is described to accommodate the following 15 new Neotropical species of Derelomini (Coleoptera: Curculionidae: Curculioninae): C. laticola, sp. n.; C. sphaerata, sp. n.; C. cordata, sp. n.; C. dentata, sp. n.; C. pilosa, sp. n.; C. capitulata, sp. n.; C. tenuicola, sp. n.; C. carinata, sp. n.; C. uncinata, sp. n.; C. oculata, sp. n.; C. cultrata, sp. n.; C. striata, sp. n.; C. bipartita, sp. n.; C. crepidula, sp. n.; and C. palmata, sp. n. The monophyly of Cyclanthura is indicated by the putatively synapomorphic elytral elevations and impressions, the posteriorly explanate female tergum VIII, and the posteriorly emarginate female tergum IX. These and various other characteristics - e.g.transformations in the apical region of the male median lobe - distinguish Cyclanthura from Phyllotrox Schönherr to which its species would have been assigned until now. Particular species of Cyclanthura are considered to pollinate and reproduce on the inflorescences of Araceae (Anthurium) and Cyclanthaceae (Asplundia, Carludovica, Sphaeradenia, and Cyclanthus). Several significant host plant transitions appear to have evolved within the genus. These patterns are discussed in the light of a phylogeny of the species of Cyclanthura which is based on an analysis of 22 taxa and 32 characters.