Determination of population fluctuation of tetranychus urticae koch (acarina: tetranychidae) in the cotton fields Diyarbakir province, Turkiye

Two-spotted spider mite, Tetranychus urticae Koch (Acarina: Tetranychidae), is one of the most important pests of cotton fields. This study was conducted in Diyarbakır province (Bismil, Çınar and Sur) in 2023 and 2024 to determine the population change of T. urticae. This study were carried out in three different cotton fields in Bismil (Ağıllı), Çınar (Yuvacık) and Sur (Sati) districts, and nymphs and adults of T. urticae were counted every week from the 2-4 leaf stage of cotton until the harvest period. According to the data obtained from the studies, the population density of T. urticae differed in 2023 and 2024 production years. It was determined that the population density of T. urticae was higher in the 2023 production year, in which the population fluctuation of T. urticae was followed, than in the 2024 production year. When the population density of T. urticae was analyzed, it was observed that the highest population density was reached at the end of July with 48,0 numbers of individual/leaf in Bismil - Ağıllı and 52,0 numbers of individual/leaf in Çınar-Yuvacık in 2023, while the highest population density was reached at the beginning of June with 48,0 numbers of individual/leaf in Sur-Sati in the same year. In the observations made in 2024; 36,0 numbers of individual/leaf in Bismil - Ağıllı, 36,0 numbers of individual/leaf in Çınar-Yuvacık reached the highest population density in mid-July, while 34,3 numbers of individual/leaf in Sur-Sati reached the highest population density in early July.