Climate change is expected to have an impact on pest management in different agroecosystems. pest management strategies in these agroecosystems may need to be adjusted in responses to long term changes in pest populations. the whitefly bemisia tabaci (gennadius) (hemiptera: aleyrodidae) is an important pest on a global scale because of its voracious feeding and its role in transmission of numerous plant viruses in many agroecosystems. a field study was conducted to help elucidate the impact of climate change on populations of whiteflies in vegetable agroecosystems in egypt. mild winter temperatures allow whiteflies to live year-round in these agroecosystems. predictions of populations of b. tabaci were done for agroecosystems in three egyptian governorates (dakahlia, damietta, and sohag). the sohag site was in the nile valley (about 520 km south of cairo). the other two sites (dakahlia and damietta) were in the nile river delta (about 110 km and 155 km north of cairo, respectively). historical seasonal patterns as well as long-term values (for the years 2041 and 2070) of populations of whiteflies were estimated. the results based on our analysis of the temperature and whitefly population patterns spanning an excess of three decades (from 1980 to 2013) support that the temperature continued to rise, and the whitefly population continued to increase among years in each agroecosystem. results from this research will help agricultural stakeholders in understanding the impact of changing environments on populations of whiteflies.