Abstract: In this study, the key climatic factors in spawning, overwintering,and hatching periods of grasshopper were taken as the main factors to establish the climatic suitability index of potential occurrence of grasshopper (POG) in Inner Mongolia, and an  evaluation was conducted on the climatic suitability of POG in Xianghuangqi County of Inner Mongolia in 2010. Based on the field investigation data collected in early and mid July 2010, seven relatively stable habitat factors including elevation, aspect, soil type, soil sand content, vegetation type, vegetation coverage, and land cover type were selected, and the habitat suitability for POG throughout the County was estimated by using fuzzy evaluation combining with 3S (GIS, RS, and GPS) technology. The POG ranks in 2010 were estimated by integrating the climatic and habitat suitability for POG. The simulated locations where grasshopper occurred were verified by the field investigation data in 2010, and the simulated areas infected by grasshopper were verified by historical data from 2001 to 2010. The results confirmed that the estimated POG ranks were reliable. The climatic suitability for POG was very homogeneous over the study area, and the vast majority of the study area was in the rank of “suitable”. The spatial heterogeneity of the potential locations where the grasshopper might occur was mainly related to habitat factors. The highest POG rank was found at the locations with elevation 1300-1400 m, flat or aspect of east or south, typical chestnut soil, soil sand content 60%-80%, and vegetation coverage 30%-50% in temperate bunchgrass steppe.

Key words: grassland grasshopper plague, climatic suitability, habitat suitability, fuzzy evaluation, 3S technology, integrated evaluation model