Prevalence of Tetranychus urticae Koch and T. turkestani (Ugarov & Nikolskii) (Acari: Tetranychidae) and their endosymbiotic bacteria in cotton fields of Aydin, Türkiye

Spider mites are important pests of cotton, a vital fiber crop cultivated in sun-drenched regions. This study investigated the prevalence and distribution of spider mite species infesting cotton fields in Aydin province, Türkiye. Spider mites were found in a significant portion (89%) of the surveyed fields. The two most abundant mite species, were the red form (RF) of Tetranychus urticae (57.1%) and T. turkestani (39.3%). A minor presence of T. urticae green form (GF) (3.6%) was observed. Tetranychus urticae RF was more prevalent in coastal areas, while T. turkestani was more common inland. Field surveys demonstrated that areas with higher T. urticae RF prevalence exhibited more frequent spraying, potentially due to this species’ greater capacity to develop resistance compared to T. turkestani. This study also investigated the prevalence of Wolbachia, Rickettsia, Cardinium and Spiroplasma endosymbionts, which are linked with pesticide resistance due to their ability to degrade pesticides, in these mite populations. The study confirmed the presence of Wolbachia and Rickettsia endosymbionts in spider mite populations in Türkiye. However, no Cardinium or Spiroplasma were detected in any of the populations. Infection rates of the detected endosymbionts differed between T. urticae and T. turkestani. Future studies should investigate the resistance levels of these tetranychid mite species as well as the role of their endosymbiotic bacteria in resistance in cotton-growing areas.