This study aims to explain the genetic kinship relationships among populations of the psyllid species collected from several pistachio orchards in Turkey. Agonoscena pistaciae (Burckhardt and Lauterer) (Hemiptera, Psyllidae) is one of the most important pests of pistachio trees (Pistacia vera L.). This species, which continues its biological periods on pistachio trees, has been rapidly spreading in some parts of the world. Although pistachio psyllid leads to significant yield losses in pistachio trees in Gaziantep and Adiyaman in Turkey, in Siirt province such infestation has historically been very rare. However, the population density has significantly increased in Siirt province and districts in recent years. In this study, an internal transcribed spacer (ITS) DNA barcode identifier was used to determine whether these new outbreaks are a simple spread or the evolution of a new A. pistaciae biotype. In this context, by obtaining a 716-bp long ITS gene region by the polymerase chain reaction process, the genetic kinship relationships among populations of A. pistaciae in Gaziantep, Adiyaman, and Siirt provinces, which have significant potential in pistachio production, were revealed. When the data obtained were examined, no genetic differences could be detected among the population members of A. pistaciae spreading in Siirt, Gaziantep, and Adiyaman provinces. It was determined that A. pistaciae living in these regions are the same species. In addition, in the study the Wolbachia sp. type using the 16S ribosomal RNA gene region was determined.