Intense Appearance of Chestnut Gall Wasp (DryocosmuskuriphilusYasumatsu) in Bosnia and Herzegovina

Abstract

This paper presents the research of biological characteristics, prevalence, intensity of appearance in year 2016 and 2017 and a prognosis of further expansion of chestnut gall wasp (Dryocosmus kuriphilus Yasumatsu) in Bosnia and Herzegovina. Chestnut gall wasp is an invasive, quarantine pest which was first time registered in year 2015 on 34 locations in Bosnia and Herzegovina. In year 2016, this specific pest was found on 41 location, and in 2017 it was found on 48 locations. Research has shown that the expansion location of chestnut gall wasp has expanded in relation to localities from the first findings in 2015. Based on the research results, a hot spot map of chestnut gall wasp in Bosnia and Herzegovina has been made for 2017. First galls were found on June 2 nd in 2016, and on June 5 th in 2017. First adult chestnut gall wasp was found on July 3 rd in 2016, and on July 8 th in 2017. The study also determined the intensities of the D. kuriphilus phenomenon in all sites where this pest was found, and the intensity of occurrence (category 3) was the highest on the sites in the municipality of VelikaKladuša and Cazin. Intensive appearance of chestnut gall wasp creates a possibility of expansion of chestnut blight fungus (Cryphonectriaparasitica (Murr.) Barr. According to research in Switzerland, there is a possibility for new entry spots for the spores of chestnut peel cancer through abandoned galls of chestnut gall wasps, which fungi can saprophytically populate, which can cause spreading of the infection to neighboring branches. Due to that problem, it is necessary to conduct a research to determine if there is a risk of spreading of this disease in the areas of sweet chestnut (Castanea sativa) in Bosnia and Herzegovina.