The study of external morphology of the New Caledonian leaf beetle Dematochroma foaensis Jolivet, Verma & Mille (Chrysomelidae, Eumolpinae, Colaspoidini) substantiates its new combination into the genus Rhyparida Baly (Chrysomelidae, Eumolpinae, Nodinini). The species is redescribed here to highlight characters important for suprageneric diagnosis. This is the second species of Nodinini found in New Caledonia, otherwise rich in species of Colaspoidini, raising questions about the paucity of Rhyparida and this tribe in New Caledonian fauna, when they are dominant in surrounding archipelagoes, and very rich in potential source areas such as Australia and New Guinea. Some alternative explanations for this pattern are advanced, serving as alternative hypotheses until our knowledge on the ecology of these species improves or supported phylogenetic scenarios become available for this group.