Planococcus citri (Risso) (Hemiptera: Pseudococcidae) is one of the most significant pests for especially citrus, crop plants and ornamental plants. Besides its worldwide importance, chemical control is a significant, major method to suppress the population of P. citri in Turkey. Moreover, biological control has become more important in recent years because of the increase in consumer consciousness about pesticides. For this reason, the population dynamic of P. citri and its predator, Sympherobius pygmaeus (Rambur) (Neuroptera: Hemerobiidae) in three different grapefruit orchards were studied. For the study, 10 trees were randomly chosen from each orchard and the individuals on the plants, 4 branches, and stem of each tree were counted to determine the population level. When P. citri population reached the peak level, approximately 500 S. pygmaues individuals were released to each orchard. Population levels of prey and predators were monitored for two years, with weekly intervals between May-October and one time for two weeks between December and April of the following year. As the result of the treatment process, it is observed that the predator S. pygmaeus succeeded in decreasing the population of P. citri under economic damage threshold level. As a result, it is demonstrated that the predator S. pygmaeus can be used as a biological agent against P. citri in integrated pest management programs as an environmentally friendly method.