Diversity, distribution and conservation status of the South American dichroplines (Orthoptera: Acrididae)

SCATOLLINI, M.C.; LIRA-NORIEGA, A.; CIGLIANO, M.M.

Agadir

Congreso; 13th International Congress of Orthopterology; 2019

The South American tribe Dichroplini presents 163 species, belonging to 28 genera. The group inhabits open biomes encompassing very different geomorphological areas of South America and are particularly diverse in the Seasonally Dry Tropical Forests (SDTFs) open bioma. The tribe exhibits the greatest diversification of South American melano-plines, being the dominant group both in number of species and individuals in most grassland communities Two main diversifica-tion centers occurring in the Northern Andes (Colombia and Venezuela) and the Para-no-Platense basin had been proposed for the tribe.Determining what processes have generated biodiversity is a major goal of evolutionary bi-ologists, ecologists, and conservation biolo-gists. Despite often characterized as less rich than tropical rainforests South America open biomes have high levels of endemism and are very important to understand biogeographic patterns at the continental scale, and are therefore worthy of more focused research and conservation efforts. There is an urgent need to set spatial priorities in highly threat-ened regions, incorporating biotic elements and conservation biogeographical analyses should be seen as a top research priority to safeguard the evolutionary significance of bio-diversity hotspots.The main objective of this work is to explore the diversification patterns of the species and genera of the Dichroplini tribe and to contrast various hypotheses proposed to explain the spatial variations in speciation rates with the patterns of diversification in the tribe..The diversity patterns of the species and gen-era were analysed considering the richness range size and niche breadth. The results sug-gest that the diversification centers of the Di-chroplini tribe would coincide with those men-tioned for the group (Northern Andes and Parano-Platense basin), adding a third evolu-tionary center in the Central Andes region. The Andes are characterized by brachypterous species, with reduced niche breadths and ranges, with a high degree of endemisms and high regional richness. The evolutionary center of the Parano-Platense basin presents the greatest diversification of the tribe, finding the greatest richness in the Paranense Atlantic Forest and Humid Chaco of the Seasonally Dry Tropical Forests (SDTF) and in the Araucaria Forest of Tropical Rain Forest, characterized by brachypterous and macropterous species with variable distribution ranges. Also, RedList Assesments of several species were elaborated trying to determine spatial priorities regarding the conservation of Dichroplini.