This research was conducted within the border of Bartin province between the years of 2015-2018 for making detailed research on the biology of the important walnut pest Garella musculana identified for the first time in Turkey. The pupas collected from the study area were brought to the laboratory and monitored. It was observed that some pupas were parasitic, and the type of parasitic species that emerged from these pupae was also recorded and the species were diagnosed. As a result of the diagnosis, the parasitoid species were identified as Pimpla spuria (Gravenhorst, 1829). This was the first parasitoid recorded on Garella musculana in Turkey. This situation should be helpful of biological control on Garella musculana in walnut orchards.