Endemic grasshoppers (Orthoptera, Acridoidea) of the steppes of West Siberia and North-East Kazakhstan: how can we estimate their future?

The distribution patterns of 3 rare acridid species, namely Asiotmethis jubatus (Uvarov, 1926) (Pamphagidae), Aeropedellus baliolus Mistshenko, 1951 and Mesasippus arenosus (Bey-Bienko, 1930), are described and compared. In the region, there are the type localities of these species. A. jubatus and M. arenosus are very rare and mainly associated with the dry steppes and the semi-deserts of the region, while A. baliolus are more or less common and distributed over the steppes from their northern boundary up to the southern one. The ecologo-geographic modelling based on the Maxent approach allows to reveal the potential distribution patterns of habitats applicable for each species to forecast possible shifts of species distributions relative to feasible climatic changes according the Shared Socioeconomic Pathway 3-7.0 and the global climate model CNRM-ESM2-1. The comparative analysis of the species distributions, the predicted distributions of suitable conditions and the forecasts of their possible shifts showed that predictions for the endemic steppe species can be quite different. The forecasts for A. jubatus and M. arenosus based on the species distribution models and the predictions of high greenhouse gas emissions show that they may become relatively prosperous in the middle of the 21st century and the northern boundaries of the optimal parts of their ranges may shift northward. The predictions for A. baliolus show that the species optimal territories may catastrophically reduce in the future (from 265,000 km2 now up to about 18,000 km2 in the middle of the 21st century). As a result, the conservation status of A. baliolus may significantly change, because it will explicitly meet the IUCN criteria of the Vulnerable species.