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A new revision of an endemic genus of leaf beetles from New Caledonia

Jesús Gómez-Zurita, researcher of the Entomology and Insect-Plant Interactions group of the IBB, recently published together with Maria Pàmies, a former undergrad student in his lab, a revision of a group of Eumolpinae leaf beetles from New Caledonia. This work is part of a long-term project by this researcher to document and classify a hyperdiverse radiation including hundreds of species of Eumolpinae that evolved in situ in the remote Pacific island of New Caledonia.

In this particular case, the focus has been on a monophyletic assemblage of species, i.e. a cohesive group of species derived from a common ancestor, including the species Thasycles cordiformis, described by Félicien Chapuis in 1874 to characterize his new genus Thasycles. This genus had been sunk in synonymy soon after it was proposed, and despite attempts to resurrect it by a German author, Karl Heller, in 1916, it finally disappeared from the taxonomic literature, in favour of the older name Dematochroma Baly, 1864, applied to many species of New Caledonian Eumolpinae.

Figure. Thasycles magnus Gómez-Zurita is one of the new species described in the work of Gómez-Zurita & Pàmies-Harder, a large, magnificent beetle that went unnoticed so far. The mitochondrial DNA phylogeny of the genus Thasycles as a fundamental tool to investigate species limits and relationships.

The authors use molecular phylogenies to demonstrate that the type species of Dematochroma is not related to T. cordiformis and use this information to recover Chapuis’ generic name for this species and for the entire assemblage of closely related species studied in this work. In this revision, which combines morphological and mitochondrial DNA data to study species diversity, three species previously ascribed to Dematochroma are transferred to Thasycles and seven new species are described, bringing from one to eleven the total of species currently included in the genus Thasycles. The research group previously revised the Eumolpinae genera Acronymolpus Samuelson, Kumatoeides Gómez-Zurita, Taophila Heller and Tricholapita Gómez-Zurita & Cardoso, approaching little by little the goal of describing the entire diversity of this fascinating endemic island radiation.


Gómez-Zurita, J. & Pàmies-Harder, M. 2022. Phylogenetic restitution and taxonomic revision of the New Caledonian endemic genus Thasycles Chapuis (Coleoptera: Chrysomelidae, Eumolpinae). Zoologischer Anzeiger 297: 16-41.

Author: Jesús Gómez-Zurita

Nomenclatural type catalogue