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

LIRA-NORIEGA, ANDRÉS; CIGLIANO, MARÍA MARTA; SCATTOLINI, MARÍA CELESTE

Agadir

Congreso; 13th International Congress of the Orthopterists´ Society; 2019

IBN ZOHR University of Agadir/ National Center for Control of Desert Locust /Orthopterists? Society

The South American tribe Dichroplini presents163 species, belonging to 28 genera. Thegroup inhabits open biomes encompassingvery different geomorphological areas ofSouth America and are particularly diverse inthe Seasonally Dry Tropical Forests (SDTFs).The tribe exhibits the greatest diversificationof South American melanoplines, being thedominant group both in number of species andindividuals in most grassland communities. Twomain diversification centers occurring in theNorthern Andes (Colombia and Venezuela) andthe Parano-Platense basin had been proposedfor the tribe.The main objective of this work is to explore thediversification patterns of the species and generaof the Dichroplini tribe and to contrast varioushypotheses proposed to explain the spatialvariations in speciation rates with the patterns ofdiversification in the tribe.The diversity patterns of the species and generawere analysed considering the richness, rangesize and niche breadth. The results suggest thatthe diversification centers of the Dichroplinitribe would coincide with those mentionedfor the group (Northern Andes and Parano-Platense basin), adding a third evolutionarycenter in the Central Andes region. The Andesare characterized by brachypterous species, withreduced niche breadths and ranges, with a highdegree of endemisms and high regional richness.The evolutionary center of the Parano-Platensebasin presents the greatest diversification ofthe tribe, finding the greatest richness in theParanense Atlantic Forest and Humid Chacoof the Seasonally Dry Tropical Forests (SDTF)and in the Araucaria Forest of Tropical RainForest, characterized by brachypterous andmacropterous species with variable distributionranges. Also, Red List assessments of 41 out of163 (25 % of the species) species were elaboratedto aid in determining spatial priorities regardingthe conservation of Dichroplini.This work highlights the value of South Americanopen biomes as areas of high endemism andkey regions to understand biogeographicpatterns. Such ecosystems urge for researchand conservation efforts. Spatial prioritizationproposals incorporating biotic elements andconservation biogeographical analyses shouldbe seen as a top research priority to safeguardthe evolutionary significance of these biodiversityhotspots.