Cynipini (Hymenoptera: Cynipidae) fauna of Van province oak forests

This study was conducted as a "Master's Thesis" in the Department of Forest Engineering at Isparta University of Applied Sciences, Graduate School of Education, between 2023 and 2024, with the aim of identifying Cynipini species causing gall formation in oak forests in Van province. The study was conducted in three locations (Gevaş-Değirmitaş, Gevaş-İnköy, and Çatak) within the study area, with a total of six sample sites. When selecting the sample areas, attention was paid to areas with dense oak forests and different ecological characteristics such as elevation. Gall samples were collected from various parts of oak trees in the sample areas (including Quercus infectoria subsp. boissieri, Q. libani, Q. petraea subsp. pinnatiloba, and Q. robur subsp. pedunculiflora), including stems, young shoots, acorns, leaves, and flowers, and brought to the laboratory. The galls were separated based on their morphological characteristics, and information such as the number of galls, the part of the plant where the gall was found, the host plant species, collection date, coordinates, elevation, slope, aspect, and slope position were recorded. A total of 50 gall wasp species belonging to 10 genera were identified in the study. Andricus species accounted for 62% of the species, with 40 species being first recorded in Van province. The oak tree species with the highest number of gall wasp species was Q. robur subsp. pedunculiflora with 31 species, while the lowest was Q. libani with 8 species. The species with the highest gall density were Neuroterus quercusbaccarum (1448 individuals), N. anthracinus (765 individuals), and Cynips quercusfolii (612 individuals). Gall density was highest in the Gevaş-Değirmitaş location and lowest in the Gevaş-İnköy location. This study has made significant contributions to the Cynipini fauna of Van province by adding 40 species. It has also highlighted the species richness of the Eastern Anatolia Region, thus making important contributions to the regional Cynipini fauna.