Determination to Cynipidae fauna and associated insect species of taxa (Quercus spp.) in the Eastern Mediterranean Region of Türkiye

Galls are atypical plant growths that cause an increase in both the number and size of cells in a plant, driven by parasitic organisms (such as insects, bacteria, or fungi) for feeding, shelter, and protection purposes. Among these organisms, insects are the most common causes of galls. Within insects, 52 different families across 6 orders can induce gall formation in plants. Among these, the family Cynipidae (Hymenoptera) represents the second most diverse group in terms of species that induce galls, following the gall midges (Diptera: Cecidomyiidae). Members of the Cynipini tribe within the Cynipidae family induce galls on Fagaceae species (such as Quercus, Castanea, Castanopsis, Chrysolepis, Lithocarpus, and Notholithocarpus). Meanwhile, members of the Ceroptresini and Synergini tribes within the same family (except for the Synophrus species) inhabit the galls created by Cynipini tribe members as inquilines, specifically as oak gall wasps. Additionally, some inquiline insect species such as Coleoptera, Diptera and Lepidoptera, as well as parasitoid species within the Chalcidoidea superfamily, use the gall as a reproductive site. Together with microorganisms and other organisms, these groups form a complex structure that constitutes the oak gall wasp and its community. In this study, the community of inquiline, parasitoid, and visiting insects associated with Cynipini tribe oak gall wasps on 11 different Quercus taxa naturally occurring in the Eastern Mediterranean region of Türkiye were investigated. The research was conducted in natural Quercus (oak) areas within the Eastern Mediterranean region of Türkiye, specifically in the Adana Province (which is part of the Mediterranean Geographical Region) and its surrounding areas (Gaziantep, Kilis, and Karaman—only the Ermenek district and Niğde) from 2019 to 2024. A total of 237 different samples were collected from the study area. After being purified in the laboratory, the samples were cultured in appropriately sized containers. The samples were checked every 15 days. Hymenoptera specimens were transferred to cryo tubes containing 70% alcohol, while Coleoptera and Lepidoptera specimens were prepared according to the technique and preserved as permanent collections. The preliminary identification of the specimens was done according to the literature and then confirmed by a subject expert. As a result of the study, a total of 98 species from 26 genera across 3 orders were identified, including: 67 species belonging to 13 genera of oak gall wasps (Hymenoptera: Cynipidae), 21 species belonging to 9 genera of parasitoids (Hymenoptera), 9 species belonging to 3 genera of inquilines (Hymenoptera and Lepidoptera), and 1 species from 1 genus of visiting insects (Coleoptera). Among the 67 oak gall wasp species identified, Dryocosmus mikoi was found to be a new record for the Cynipidae fauna of Turkey. With this record, the number of Cynipidae species in Türkiye has increased from 172 to 173, and the number of oak gall wasp species has risen from 124 to 125. Additionally, six Chalcidoidea (Hymenoptera) species from the parasitoid group have been identified as new records for the insect fauna of Türkiye. These are Aulogymnus testaceoviridis (Eulophidae), Sycophila binotata (Eurytomidae), Ormocerus sp. dif. dirigoius (Pteromalidae), Ormyrus destefanii (Ormyridae), Torymus affinis, and T. eglanteriae (Torymidae). Thus, within the scope of this study, a total of 7 species were determined to be the first records for the insect fauna of Türkiye. Among the identified species, Andricus superfetationis, Pammene gallicolana, and Torymus auratus have been reported from Türkiye for the second time in this study. In addition, Pseudoneuroterus saliens (Kollar, 1857)-sx has been recorded for the first time as a host of Bootanomyia hepdurgunae, which previously had no known host record in the world. Furthermore, Andricus truncicola-ag has been added to the host list of Sycophila flavicollis, A. quercusramuli-sx to the host list of Sycophila iracemae, Chilaspis nitida-sx to the host list of Sycophila variegata, and Synophrus politus to the host list of Ormyrus destefanii through this study. Of the 98 species identified in the study, 84 are reported from the Eastern Mediterranean region for the first time through this study. Among the identified species, 37 are recorded for the first time in the Cynipid fauna of the Mediterranean region, 30 in the Southeastern region, and 27 in the Central Anatolia region. Until now, the Eastern Mediterranean Cynipidae fauna was represented by 18 species. As a result of this study, it has been determined that the fauna now includes a total of 82 species: 67 species from the Cynipini + Synergini groups [66 Cynipini + 1 Synergini (only the Synophrus species)], 5 species from Synergini, 2 species from Ceroptresini, and 5 species from the Diplolepidini tribe. In addition, detailed information on host records, new distribution data, and other findings for many species are provided.