evaluation of pyrethroid susceptibility in culex pipiens of northern izmir province, turkey

Background: mosquitoes, being a nuisance species, are considered as one of the most important species in public health control programs due to their role as a vector in mosquito-borne diseases observed in humans and animals. we evaluated the susceptibility status of culex pipiens collected from northern izmir, turkey in 2011-16. methods: mosquito larvae, collected from three different locations in northern izmir, were reared in the laboratory. adult susceptibility bioassays were performed using the who insecticide-impregnated papers including deltamethrin 0.05%, permethrin 0.75%, α-cypermethrin 0.05% and cyfluthrin 0.15%. in addition, adult bioassays were performed after the pre-exposure to piperonyl butoxide (pbo) to determine the contribution of p450 detoxification enzymes to the phenotypic resistance. results: in all of the three populations, high levels of resistance were observed (mortalities<63%) to all of the four pyrethroids. different pyrethroids but with the same mode of action can exhibit significantly different phenotypic resistance in a single population. pbo bioassays also showed that p450 detoxification enzymes can have diverse effects on different pyrethroids. conclusion: using just one chemical in a class of insecticide can be misleading for resistance studies.