The present investigation establishes deltamethrin resistance in the common bed bug, Cimex lectularius, populationcollected from New York City (NY-BB). The mortality resistance ratio indicated that NY-BB population was 264-fold more resistant to 1% deltamethrin in contact bioassay compared to one insecticide- susceptible population collected in Florida (FL-BB). Specific enzyme activities (general esterase, glutathione S-transferase, and 7-ethoxycoumarin O-deethylase) of NY-BB were not statistically different from those of FL-BB, indicating that the metabolic factors are not associated with the deltamethrin resistance in NY-BB. Complementary DNA fragments that encoded the open reading frame of voltage-sensitive sodium channel α-subunit genes from the FL-BB and NY-BB were obtained by homology probing PCR and sequenced. Sequence alignment of the internal and 5’ and 3’ RACE fragments generated a 6500 bp cDNA sequence contig, which was composed of a 6084 bp open reading frame (ORF) encoding 2027 amino acid residues and 186 bp 5’ and 230 bp 3’ untranslated regions (5’ and 3’UTRs, respectively). Sequence comparisons of the complete open reading frames of the sodium channel genes identified two point mutations (V419L and L925I) that were presented only in the NY-BB population. L925I, located the intracellular loop between IIS4 and IIS5, has been previously found in the pyrethroid-resistant populations of whitefly (Bemisia tabaci) that was more than 100-fold resistant to fenpropathrin. V419L, located in the IS6 transmembrane segment, is a novel mutation. This evidence suggests that the two mutations are likely the major resistance-causing mutations in the deltamethrin-resistant NY-BB via a knockdown-type nerve insensitivity mechanism.

배추좀나방의 deltamethrin에 대한 약제 저항성 기작을 알기 위하여 에스테라제의 활성과 조성을 분석하였다. 0.1의 deltamethrin으로 매 세대 선발하였을 때 선발세대의 진행에 따라 배추좀나방 4령충의 약제감수성은 줄었고 에스테라제 활성을 증가했다. Deltamethrin으로 선발된 또는 선발되지 않은 서로 다른 배추좀나방 집단들의 약제감수성과 에스테라제 활성간에 높은 상관을 보였으며 이들 요인들간에 상관계수는 0.9918(P=0.0082)로 정상관을 보였다. 전기영동(6% gel)의 결과 17개의 에스테라제 밴드가 분리되었다. Deltamethrin에 대해 선발된 집단들은 비선발 집단에 비해 적은 숫자의 에스테라제 밴드를 보여주었다. 그러나 4개 밴드(E3, E4, E11, E12)는 deltamethrin 선발집단에서만 나타난 밴드였다.