Differences in Grasshopper Movement in Latitude and Altitude in the Context of Climate Change—The Example of the Ili River Basin in Xinjiang, China

Global warming has caused various taxa to migrate to different latitudes and altitudes. This study aimed to clarify changes in the community composition of grassland locusts and grasshoppers in the context of climate change, as well as their response patterns to climate warming. Choosing the Ili River basin in Xinjiang of China as the study area, this study comparatively analyzed the changes in the species temperature index (STI) and community temperature index (CTI) of locusts and grasshoppers historically (1986–1988) and recently (2022–2023). The aim was to elucidate the differences in the community composition of locusts at different latitudes and altitudes, and their responses to climate warming. The results showed that, under the influence of climate change, locusts and grasshoppers migrated northward in latitude at a rate of about 1.45 km per year. In areas with an altitude of < 1158 m, thermophilic species migrated to mid-altitude regions with suitable temperatures. In areas with an altitude of > 1158 m, psychrophilic species migrated to habitable high-altitude regions. In areas with an altitude of 1158 m, the number of thermophilic species migrating to lower altitudes was similar to the number of psychrophilic species migrating to higher altitudes. We found that, in the context of climate change, the relative composition of thermophilic species and psychrophilic species in the communities of locusts and grasshoppers changed in the Ili River basin over the two different periods. Moreover, locusts and grasshoppers migrated and diffused in different ways at different latitudes and altitudes to cope with climate change.