Determining the distribution and the damage ratio of the chestnut gall wasp dryocosmus kuriphilus yasumatsu (Hymenoptera: Cynipidae) in Turkey

Chestnut gall wasp, Dryocosmus kuriphilus Yasumatsu (Hymenoptera: Cynipidae) is an alien invasive species which recorded in Turkey in 2014 in Yalova region and still expanding its range. This species, being originially from China, has spread to many countries and has caused significant losses in all production areas (fruit, wood, honey) related to the chestnut tree. In the present thesis, the distribution and damage ratio of the chestnut gall wasp in Turkey were investigated. It was found that the chestnut gall wasp expanded its range in Turkey by a speed of 25 km/year between 2014 and 2017. Additionally, it was found that the pest population and thus its damage increased significantly between 2016 and 2018 in Bursa, İstanbul (Şile) and Yalova; and its damage in Kocaeli (Karamürsel) is over the economic damage threshold. We suggest these localities as priority localities for pest management. Keywords: Chestnut gall wasp, Dryocosmus kuriphilus, Distribution, Damage ratio, Turkey