Tehran University of Medical Sciences Journal of Arthropod-Borne Diseases 2322-1984 17 3 2024 01 07 1581 1581 Huseyin Cetin Department of Biology, Faculty of Science, Akdeniz University, Antalya, Türkiye Atila Yanikoglu Department of Biology, Faculty of Science, Akdeniz University, Antalya, Türkiye Esin Akarsu Department of Chemistry, Faculty of Science, Akdeniz University, Antalya, Türkiye Mehmet Civril Department of Biology, Faculty of Science, Akdeniz University, Antalya, Türkiye Eylul Odabas Department of Chemistry, Faculty of Science, Akdeniz University, Antalya, Türkiye Samed Koc Department of Biology, Faculty of Science, Akdeniz University, Antalya, Türkiye, Laboratory Animals Application and Research Centre, Akdeniz University, Antalya, Türkiye Emre Oz Department of Biology, Faculty of Science, Akdeniz University, Antalya, Türkiye, Department of Medical Services and Techniques, Vocational School of Health Services, Dialysis Programme, Antalya Bilim University, Antalya, Türkiye Burak Polat Department of Biology, Faculty of Science, Akdeniz University, Antalya, Türkiye 2022 09 10 2023 09 02 Background: The house fly, Musca domestica, is vector for pathogens and parasites and causes economic damage to livestock by reducing forage conversion efficiency, negatively impacting weight gain and milk production. It has shown resistance to multiple insecticide classes. The aim of this research was to determine the susceptibility levels of seven­teen field M. domestica strains to thiamethoxam, a neonicotinoid insecticide, in Türkiye. Methods: Insecticide susceptibility of the house flies to thiamethoxam was determined using the WHO glass jar meth­od. A probit analysis program was used to determine LD50 values, and then the resistance ratios were compared with insecticide-susceptible strain. Results: All strains were ≥18.5-fold resistant to thiamethoxam. The data showed that 10 out of 17 strains had either high or very high resistance levels. Our findings revealed that house flies from solid waste landfills in Samsun, Ankara, and Kocaeli exhibited higher resistance ratios compared to those found in animal shelters. Conversely, in Gaziantep, Antalya, İzmir and Erzurum, the exact opposite trend was observed. Regarding the LD50 values among solid waste stor­age areas, the lowest rate was obtained from Gaziantep (0.72 gr ai/m2), and the highest rate was obtained from Ankara (9.35 gr ai/m2). Furthermore, regarding the LD50 values among animal shelters, the lowest was obtained from Samsun (0.37 gr ai/m2), and the highest was obtained from Denizli (21800 gr ai/m2). Conclusion: The use of integrated control systems is recommended for controlling house fly populations, including insecticide class rotations for preventing, or at least, delaying the onset of resistance. https://jad.tums.ac.ir/index.php/jad/article/view/1581 https://jad.tums.ac.ir/index.php/jad/article/download/1581/632