Geadephaga (Insecta: Coleoptera) from the sub-Antarctic Tierra del Fuego archipelago: species-richness, distribution maps and taxonomic key

The Tierra del Fuego Archipelago (TFA), situated at the southernmost tip of South America, represents a region of great biogeographical importance facing rapid environmental changes due to anthropic activities and climate change. In this context, the assessment of the sub-Antarctic biodiversity of the TFA is becoming increasingly important. Among invertebrates, insects are the most diverse group in the TFA, still they are largely unexplored. The order Coleoptera is particularly dominant in the TFA, with the Geadephaga group being a recognized natural group that plays key ecological roles in both natural and agricultural ecosystems. Although the species richness of Geadephaga is lower in sub-Antarctic environments than in subtropical archipelagos, these beetles exhibit a remarkable degree of endemism, emphasizing their unique evolutionary significance in sub-Antarctic habitats. In this contribution, we present a comprehensive list of Geadephaga species in the TFA, along with a taxonomic key, illustrated images of adult specimens, and distribution maps, to improve the understanding of their biogeographic patterns. We report a total of 52 species (one Cicindelidae and 51 Carabidae), including ten newly recorded species and three new putative taxa. The species richness of the TFA surpasses that of the other sub-Antarctic islands. Our findings reveal distinct biogeographical patterns associated with Nothofagus forests, the Magellanic moorlands, and the Patagonian steppe, indicating the influence of climatic conditions on beetle diversity. Our outcomes underline the importance of studying the ecological and evolutionary processes that shape the biodiversity of this sub-Antarctic archipelago.