Abstract:  Temperature is one of important environmental factors affecting on insects in the Tibetan Plateau, a region sensitive and vulnerable to climate warming, for the cold plateau climate. As an endemic species, Locusta migratoria tibetensis Chen may respond to warming climate on the plateau by increase of the accumulated degree-days (ADD) from habitat and expansion of its distribution. In order to depict the relationship between temperature changes and the ADD of the locust and to predict the distribution and occurrence of the locust in this region under the conditions of climate warming, we used surface temperature data from 90 weather stations on the Tibetan Plateau during the period of 1961-2005 to calculate the ADD of the locust and the annual area of potential distribution (APD) in ArcGIS according to the linear regression models of the ADD to geographical position. The results suggested that climate warming could increase the locust achievable ADD and APD to a great extent. The raster ADD maps indicated that in most cases the locust was distributed along the valley of main rivers over the plateau, and the potential distribution area of the locust was about 91 081 km²(3% of the Tibetan Plateau area). The largest APD occurred in 1998, the second hottest year, was 142 988 km², which was 1.9 times the APD in 1968, the coldest year. There was a significant correlation between the APD and the annual surface temperature. The annual surface temperature increased at the speed of 0.0301℃ per year, while the APD increased at the speed of 504.38 km² per year. The ratio of the increasing speed of APD to that of temperature was 16 756.8, indicating that a little increment in temperature would bring a great extension in distribution of L. migratoria tibetensis. This study presents an example of influence of global warming on plateau ecology.

Key words: Locusta migratoria tibetensis, Tibetan Plateau, potential distribution, climate warming, accumulated degree-days (ADD)