Department of Entomology, University of California, 900 University Avenue, Riverside, CA 92521, USA.
Department of Entomology, Faculty of Agriculture, Kasetsart University, Bangkok 10900, Thailand.
J Econ Entomol. 2023 Aug 10;116(4):1321-1328. doi: 10.1093/jee/toad117.
We investigated insecticide resistance profiles of field populations of the German cockroach, Blattella germanica (L.), collected from central regions of Thailand. Seven strains (PW, RB, MTH, MTS, TL, AY, and SP) were evaluated with diagnostic doses (DD; 3 × LD95 generated from a susceptible strain) of deltamethrin, fipronil, and imidacloprid using topical assays and compared with a susceptible strain (DMSC). Results showed fipronil (2-27% mortality), deltamethrin (16-58% mortality), and imidacloprid (15-75% mortality) resistance in the field strains. Synergism studies with piperonyl butoxide (PBO) and S,S,S-tributyl phosphorotrithioate (DEF) in combination with the DD of insecticides significantly increased (P < 0.05) mortality of the test insects of the field strains suggesting the involvement of P450 monooxygenase and esterase pathways of detoxification. Gel bait evaluations demonstrated that all field-collected strains were resistant to Maxforce Forte (0.05% fipronil), Maxforce Fusion (2.15% imidacloprid), and Advion Cockroach Gel Bait (0.6% indoxacarb) with mean survival times ranging from 1.87-8.27, 1.77-11.72, and 1.19-3.56 days, respectively. Molecular detection revealed that the Rdl mutation was completely homozygous in all field-collected strains except in the PW strain. Field-collected strains were screened for 3 voltage-gated sodium channel (VGSC) mutations associated with pyrethroid resistance. The L993F mutation was present in 5 strains, but no C764R and E434K mutations were detected.
我们研究了从泰国中部地区采集的德国蟑螂（Blattella germanica（L.））田间种群的杀虫剂抗性谱。使用局部测定法（用敏感菌株生成的 3×LD95）评估了 7 个菌株（PW、RB、MTH、MTS、TL、AY 和 SP）对氯菊酯、氟虫腈和吡虫啉的诊断剂量（DD），并与敏感菌株（DMSC）进行了比较。结果表明，田间菌株对氟虫腈（2-27%死亡率）、氯菊酯（16-58%死亡率）和吡虫啉（15-75%死亡率）具有抗药性。用增效剂胡椒基丁醚（PBO）和 S，S，S-三丁基膦酸硫酯（DEF）与杀虫剂的 DD 联合进行的协同作用研究显著增加了田间昆虫的死亡率（P<0.05），这表明涉及 P450 单加氧酶和解毒的酯酶途径。凝胶诱饵评估表明，所有从田间采集的菌株对 Maxforce Forte（0.05%氟虫腈）、Maxforce Fusion（2.15%吡虫啉）和 Advion 蟑螂凝胶诱饵（0.6%茚虫威）均具有抗性，平均存活时间分别为 1.87-8.27、1.77-11.72 和 1.19-3.56 天。分子检测显示，除 PW 株外，所有田间采集的菌株均完全纯合子存在 Rdl 突变。对 3 种与拟除虫菊酯抗性相关的电压门控钠通道（VGSC）突变进行了筛选。在 5 个菌株中发现了 L993F 突变，但未检测到 C764R 和 E434K 突变。
