In this study, which takes place in the northeast of Algeria at the region of Guelma between January 2016 and June 2017, we were able to follow the spatio-temporal evolution of the main hemipteran pests in an orchard of citrus (orange variety). This monitoring showed the presence of 12 hemipteran species, their appearance in the orchard is closely linked to the sap flow. The most abundant species was Aleurothrixus floccosus. The number of the other species that found was very small or absent in most of the time. We also noted that Aonidiella aurantii and Chrysomphalus dictyospermi had a preference to develop in the center of the tree while the other species found, which are: Dialeurodes citri, Aphis gossypii, Aphis spiraecola, Lepidosaphes beckii, Parlatoria ziziphi, Saissetia olea, Coccus hesperidum, Coccus pseudomagnoliarum and Icerya purchasi, were found in the sunniest parts of the tree.