Discovery of new species of New Caledonian Arsipoda Erichson, 1842 (Coleoptera: Chrysomelidae) and insights on their ecology and evolution using DNA markers

New Caledonia is among Earth's biodiversity hotspots, and we are far from knowing how many species it sustains. We applied DNA-based methods for quick biodiversity assessment of New Caledonian Arsipoda flea beetles, enhancing the discovery and description of new species. Mitochondrial DNA phylogenetic analysis (cox1, rrnS) for four out of five known neocaledonian taxa hints at the existence of additional species, and two are confirmed and described based on morphology: Arsipoda geographica Gomez-Zurita sp. nov. and Arsipoda rostrata Gomez-Zurita sp. nov. Timing this small radiation using standard insect mitochondrial substitution rates places its origin in the Miocene. A DNA-based approach to investigate potential food plants for these herbivorous insects reveals associations with Myrsinaceae and Ericaceae, which have not yet been found in New Caledonia, suggesting that this indirect methodology may help in discovering undetected flora. Traditional taxonomy and molecular approaches cooperate here, boosting our knowledge on species inventory and ecological interactions where it is most needed.