This study aimed to predict the populations of the black scale insect, Parlatoria ziziphi (Lucas) (Hemiptera: Diaspididae), a common pest of citrus in Egypt, during period (2041 - 2070) and (2071-2100 ) compared with the pest populations of 2000, 2010 and 2012 years. Study was conducted in a citrus orchard at Ismailia District, while Ismailia weather station was used for collecting climate data (maximum and minimum air temperatures) for 2000s, 2010s and 2012s. Climate change data was conducted using climascope tool to extract the projection changes in air temperature under two RCP scenarios (RCP 4.5 and RCP 8.5). HadCM3 climate model was the base model under the two scenarios. Obtained data showed a relationship between mean temperature and nymph numbers with a good fit and a co-efficient of determination of R²= 0.974 , 0.988 , 0.958 for 2000, 2010 and 2012 years, respectively. Also, the relationship between mean temperature and adult numbers gave a good fit to the data with a co-efficient of determination of R²=0.965, 0.992 and 0.991 for 2000, 2010 and 2012 years, respectively. The estimated nymph and adult numbers for P. ziziphi under the two different climate change Scenario (RCP 4.5 and RCP 8.5) were also studied. The results indicated that the average yearly increase in nymph numbers for period (2071-2100) and period (2041-2070) under RCP 8.5 were 55.3% and 17.5%, respectively. While under RCP 4.5 were 30.9% and 12.7%, respectively . It is concluded that a directly proportional was found between temperature and the Predicted population of P. ziziphi. which could provide a valuable tool in monitoring, managing and controlling pests spread now in the coming future .