Geographical Spatial Distribution and Population Density of Wheat Stem Sawfly, Cephus pygmeus, in Wheat Fields in Southeastern, Eastern, and Northeastern Regions of Türkiye

Abstract

The wheat stem sawfly (Cephus pygmeus) is a major pest of wheat crops in many regions of the world, including Eastern Türkiye. This study aimed to investigate the spatial distribution and population density of wheat stem sawfly in Eastern Türkiye and to evaluate the damage caused by this pest on wheat yield and quality. A total of 120 wheat fields were surveyed in six provinces of Eastern Türkiye during the 2018 growing season. The results showed that the population density of wheat stem sawflies varied significantly among the surveyed fields, with an average infestation rate of 37.4%. The highest infestation rate was recorded in the province of Kilis (62.5%) and Diyarbakır (61.9%), while the lowest was in the province of Ağrı (8.3%). The study also identified some factors that affect the population density of wheat stem sawflies, including host plants (mainly wheat, barley, and rye), altitude, temperature, and geographical structure such as mountains and forests. These findings provide valuable information for developing effective management strategies to control wheat stem sawfly populations and minimize the damage caused by this pest in Eastern Türkiye, especially Southeastern Anatolia Region.