Ecologo-geographic modelling of distribution of abundant acridid species (Orthoptera, Acrididae) over South Siberia and adjacent regions

Two abundant acridid species (Chorthippus apricarius and Locusta migratoria) are widely distributed over South Siberia. Estimations of suitability conditions on the basis of the MaxEnt algorithm well correspond to the known localities of each species for the contemporary period. The main bioclimatic variables explaining these species distribution are associated with temperatures, especially those of the cold season. Predicted distribution patterns for 2021–2040 and 2041–2060 and for the scenarios of the high levels of the greenhouse gas emission show serious significant differences between the two model species. These forecasts demonstrate the explicit worsening of conditions for Chorthippus apricarius in South Siberia, and the significant expansion of territories applicable for Locusta migratoria in the southern parts of West Siberia and in Northern Kazakhstan. This trend looks like enhancing in the second half of the 21st century. The optimal areas for the migratory locust may cover the huge territories between 50° and 62° N and between the Ural Mts. and the north-western parts of the Altai-Sayan Mts. where a new area of possible outbreaks of L. migratoria may emerge. In the adjacent regions, the areas with suitable conditions for this species can expand significantly as well, including Primorskii Territory. Hence, the general continuation of global warming will most likely lead to some significant shifts in the distribution of some possible acridid pests across South Siberia.