Colonization of different biomes drove the diversification of the Neotropical Eidmanacris crickets (Insecta: Orthoptera: Grylloidea: Phalangopsidae)

Abstract

The phylogeny of the cricket genus Eidmanacris is used to analyse its historical distribution and diversification in three South American biomes: Atlantic Forest, Cerrado, and Chiquitano Dry Forest. A morphological phylogeny with all the 29 species of Eidmanacris and the Geographically explicit Event Model (GEM) is used to explain their colonization and diversification through three different biomes and their ancestral habitats and distributional areas. We analysed ecologically-significant characters, such as body size and metanotal characters, to test whether if morphology, habitat, or behaviour are connected. The relations of these features with the colonisation of wetter or drier biomes based on the distributional area, phylogeny and diversity of the genus were also tested. The results show that the ancestral distribution of the genus was the Atlantic Forest, and that biome occupancy, habitat, size, and mating behaviour evolved congruently through the phylogeny, drawing a coherent pattern of changes through Eidmanacris evolution toward the colonisation of drier biomes. Our results indicate that gallery forests could play a key role in the distribution and diversification of Eidmanacris species.