Molecular And Metabolic Insecticide Resistance In Continental Populations Of Common And Tropical Bed Bugs

We analyzed samples of Cimex lectularius and Cimex hemipterus from Europe (Spain 41 samples, Switzerland 2 samples, the Czech Republic 1 sample), Asia (Hong Kong 34 samples), and North America (United States of America 14 samples and Mexico 3 samples) and South America (Colombia 3 samples) to assess the prevalence and mechanisms of insecticide resistance. We identified specimens morphologically and barcoded them by sequencing the mitochondrial cytochrome c oxidase subunit I (COI) and the 16S ribosomal RNA (16S rRNA) genes. Additionally, we screened segments of the voltage-gated sodium channel (VGSC) and the nicotinic acetylcholine receptor (nAChR) genes for point mutations associated with insecticide resistance and measured the activity of detoxifying enzymes. All samples from North America and Europe were identified as C. lectularius, while specimens from Hong Kong were C. hemipterus, while the two species were found in Colombia. Out of 64 C. lectularius samples tested for knockdown resistance (kdr) mutations, 90.6% contained at least one known mutation. All 35 C. hemipterus samples exhibited kdr-mutations. A new mutation was identified in the pyrethroid target site in both common (F1524C) and tropical (F1450C) bed bugs. No resistance-associated mutations in the nAChR gene were found. Several populations that exhibited kdr-mutations also showed elevated activity of detoxifying enzymes.