Changing global risk of invading greenbug 'Schizaphis graminum' under climate change

Abstract

The geographical range, abundance, growth rate, survival and mortality of insects are largely influenced by abiotic factors such as temperature and humidity. When suitable, these factors can positively influence the abundance of insect pests. It is in this light that the influence of climate change, particularly global warming, has direct bearing to crop protection. In this study, we simulated the potential distribution of the greenbug or wheat aphid 'Schizaphis graminum' (Rondani) (Aphididae), a major global pest of wheat, using the climate matching tool CLIMEX (CLIMatic indEX) in global warming scenarios. To predict the potential distribution of the insect on CLIMEX at time periods 2030, 2070 and 2100, we utilize two global climate models (GCMs) at two emission scenarios. The result of CLIMEX modelling shows that the favourable climatic areas for 'S. graminum' are subtropical to temperate at the current time. With global warming, under different scenarios current suitable and highly suitable areas in the northern hemisphere are expected to expand to higher latitudes by 2030 towards 2100; while areas in the southern hemisphere, where the pest's living areas already have high temperature ranges, the occurrence of the pest will contract by 2030 since temperatures will exceed its heat limits. This study assists in predicting the potential risk areas that may be threatened by this pest in the future, providing supportive information for agricultural management practices and aid in the preparation of strategic plans to avoid possible economic damage posed by future expansion of the pest population due to climate change.