Abstract
Pistachio twig borer [Kermania pistaciella Amsel, 1964 (Lepidoptera: Tineidae)] is one of the most important pests of pistachio that opens galleries in the shoots and causes blind and sparse-grained clusters and all these damage fruit clusters. However, the infestation rates and cardinal direction preference are unknown for the pest.
This study determined infestation rate and cardinal direction preference of K. pistaciella in pistachio orchards during 2019 and 2020. The orchards located in in 25 different locations, i.e., Birecik, Bozova, Ceylanpınar, Eyyübiye, Halfeti, Haliliye, Hilvan and Karaköprü districts Şanlıurfa province Turkey. Surveys were carried out in three or four orchards representing each district included in the study. Twenty-five trees were randomly selected from each orchard and one shoot from each side of the tree was collected (100 shoots per orchard) for determining infestation and cardinal directional preference. A total 2500 shoots were observed from the study area and infestation was recorded.
The highest infestation rate was recorded for Yaslıca village in Bozova district (70%) during 2019, and Göklü village of Halfeti and Akziyaret village in Karaköprü district (29%) during 2020. The lowest infestation rate (2%) was noted for Akrepli village of Ceylanpınar district during both years of the study. Bozova and Halfeti were the most infested districts compared to the rest of the districts included in the study. The highest and the lowest infestation rate was recorded for north and west directions, respectively during both years of study. The average of two years data revealed that infestation rate for the shoots collected from the north direction was 23.68%, while it 20.33% for the shoots collected form west direction. Statistical analysis revealed non-significant difference for infestation rates of the shoots collected from different directions (χ2 = 0,9468; p = 0,8141).
The results revealed that all tree directions should be considered for the application of management practices since the pest does not prefer a specific direction. The cost of chemical control is high, but the efficacy is low, which necessitates alternative control methods for the management of the pest.