Tehran University of Medical Sciences Journal of Arthropod-Borne Diseases 2322-1984 10 4 2016 10 24 493 500 EN Mohammad Amin Gorouhi Department of Medical Entomology and Vector Control, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran Hassan Vatandoost Department of Medical Entomology and Vector Control, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran Mohammad Ali Oshaghi Department of Medical Entomology and Vector Control, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran Ahmad Raeisi National Malaria Control Department, CDC, Ministry of Health and Medical Education, Iran Ahmad Ali Enayati School of Public Health and Health Sciences Research Centre, Mazandaran University of Medical Hossein Mirhendi Department of Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran Ahmad Ali Hanafi-Bojd Department of Medical Entomology and Vector Control, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran Mohammad Reza Abai Department of Medical Entomology and Vector Control, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran Yaser Salim-Abadi Department of Medical Entomology and Vector Control, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran AND School of Health, Rafsanjan University of Medical Sciences, Rafsanjan, Iran Fatemeh Rafi Department of Medical Entomology and Vector Control, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran 2015 11 24 2015 11 24 Background: Anopheles mosquitoes are an important group of arthropods due to their role in transmission of ma­laria. The present study was conducted for determination of susceptibility status of Anopheles stephensi to different imagicides collected from malarious area in Chabahar city, Iran. Methods: In the present study seven insecticides including: DDT 4%, lambdacyhalothrin 0.05%, deltamethrin 0.05%, permethrin 0.75%, cyfluthrin 0.15% and etofenprox 0.5% were tested based on WHO method. Regression line was plotted for each insecticide using mortality of different exposure times. Bioassay data were analyzed using Probit software and the lethal time for 50% and 90% mortality (LT50 and LT90) values were calculated. Results: The susceptibility levels of field strain of An. stephensi to the discriminative dose of different imagicides were determined 100, 98, 96, 89, 82 and 62% for etofenprox, permethrin, deltamethrin, lambdacyhalothrin, cyfluth­rin and DDT, respectively. Our finding indicated that An. stephensi is resistant to DDT, lambdacyhalothrin and cyfluthrin, and susceptible to etofenprox and permethrin and candidate of resistant to deltamethrin based on WHO criteria. Conclusion: Our findings indicated that An. stephensi is resistant to DDT and some pyrethroid insecticides which can be developed due to application of insecticides in health and agriculture. These results can provide a clue for future chemical control program in the study area. https://jad.tums.ac.ir/index.php/jad/article/view/332 https://jad.tums.ac.ir/index.php/jad/article/download/332/290