Evolving resistance patterns in Tetranychus urticae and Bemisia tabaci in Greece

BACKGROUND: Pesticide resistance in agricultural pests remains a major barrier to effective and sustainable crop protection. In this study, we assessed the current resistance status of two key pests, Tetranychus urticae and Bemisia tabaci, in major agricultural regions of Greece. A total of 25 field populations were collected between 2023 and 2025 and tested using single-dose bioassays and droplet digital PCR (ddPCR) for target-site resistance mutations. \ RESULTS: The results revealed significant variability in susceptibility to multiple acaricides and insecticides. Several T. urticae populations displaying reduced sensitivity to abamectin, hexythiazox, and fenpyroximate. Resistance mutations such as I321T (GluCl3), I1017F (CHS1), F1538I (VGSC), and G126S (cytb) were detected simultaneously at high frequencies in a number of T. urticae populations, indicating multi-resistant phenotypes. A widespread occurrence of F331W (ace1), L925I/T929V (VGSC), and A2083V (acc) mutations were recorded in B. tabaci, showing the dynamics of resistance to organophosphates, pyrethroids, and ketoenols, respectively. CONCLUSION: Our findings underscore the ongoing evolution of resistance in these pests and highlight the need for integrated management strategies that include regular resistance monitoring and judicious pesticide use. This study provides resistance surveillance data to guide pest control decisions and promote sustainable Integrated Pest Management (IPM) in Greece.