Molecular analysis of pyrethroid resistance in Cimex hemipterus (Hemiptera: Cimicidae) collected from different parts of Iran

The present study was aimed to assess the bedbugs susceptibility to pyrethroid insecticides using molecular analysis. With the aid of pest control companies, adult bedbugs were collected from various places such as hotels, residential houses, and industrial buildings in seven cities highly crowded with domestic and foreign tourists in Iran from May 2016 to August 2017. Bedbugs were colonized in the laboratory to evaluate their resistance to pyrethroid using insecticide resistance bioassay. Genomic DNA was extracted from susceptible and resistant bedbugs. At first, specie specific primers targeting cytochrome oxidase subunit I (COI) gene was performed to confirm Cimex hemipterus species. Then, kdr-like gene was examined for point mutation using PCR and nucleotide sequencing. Bioassay showed that 11 out of 35 examined bedbugs were resistant to pyrethroids (31.43%; 95.00% confidence interval: 29.48-33.08%). The DNA sequencing showed that all examined bedbugs collected from Tehran province had homozygous V419L kdr-like gene mutations. The level of pyrethroid resistance found in the collected bugs from Tehran province indicated that this phenomenon has already been prevailed in the site and prompts the need to reevaluate the large use of pyrethroids to control the bedbugs.