Urban Entomology Laboratory, Vector Control Research Unit, School of Biological Sciences, Universiti Sains Malaysia, 11800 Penang, Malaysia.
J Econ Entomol. 2010 Apr;103(2):460-71. doi: 10.1603/ec09284.
The resistance profiles of 22 field-collected populations of the German cockroach, Blattella germanica (L.) (Dictyoptera: Blattellidae), from various localities in Singapore were determined by topical bioassay against novel and conventional insecticides from six classes: (1) pyrethroid (beta-cyfluthrin, deltamethrin), (2) carbamate (propoxur), (3) organophosphate (chlorpyrifos), (4) phenyl pyrazole (fipronil), (5) neonicotinoid (imidacloprid), and (6) oxadiazine (indoxacarb). Compared with a laboratory susceptible strain, resistance levels ranged from 3.0 to 468.0x for the pyrethroids, from 3.9 to 21.5x for the carbamate, from 1.5 to 22.8X for the organophosphate, from 1.0 to 10.0X for phenyl pyrazole, and were absent or low for the neonicotinoid (0.8-3.8x) and the oxadiazine (1.4-5.3x). One strain demonstrated broad-spectrum resistance to most of the insecticides. Synergism studies using piperonyl butoxide (PBO) and S,S,S-tributylphosphorotrithioate (DEF) in combination with a discriminating dose (LD99) of selected insecticides were conducted to test for possible resistance mechanisms. Resistance to pyrethroid was reduced with PBO and DEF, suggesting the involvement of P450 monooxygenase and esterases in conferring resistance. Propoxur resistance also was suppressed with PBO and DEF, and coadministration of both synergists resulted in complete negation of the resistance, indicating the involvement of both P450 monooxygenase and esterase. In six B. germanica field strains evaluated, esterases were found to play a role in chlorpyrifos resistance, whereas the P450 monoxygenase involvement was registered in three strains. Additional resistance mechanisms such as kdr-type and Rdl mutation contributing toward pyrethroid and fipronil resistance, respectively, also may be involved in some strains in which the resistance levels were not affected by the synergists. We conclude that insecticide resistance is prevalent in field German cockroach populations in Singapore.
22 个德国小蠊（Blattella germanica）田间种群对来自 6 个类别的新型和传统杀虫剂的抗药性谱，通过局部生物测定进行了测定：（1）拟除虫菊酯（β-氯氟氰菊酯、氯菊酯），（2）氨基甲酸酯（残杀威），（3）有机磷（毒死蜱），（4）苯基吡唑（氟虫腈），（5）新烟碱（吡虫啉），和（6）恶二嗪（茚虫威）。与实验室敏感株相比，拟除虫菊酯的抗性水平为 3.0 至 468.0 倍，氨基甲酸酯为 3.9 至 21.5 倍，有机磷为 1.5 至 22.8X，苯基吡唑为 1.0 至 10.0X，新烟碱（0.8-3.8x）和恶二嗪（1.4-5.3x）的抗性缺失或很低。一种菌株对大多数杀虫剂表现出广谱抗性。使用增效醚（PBO）和 S，S，S-三丁基膦三硫代酸酯（DEF）与选定杀虫剂的鉴别剂量（LD99）组合进行协同作用研究，以测试可能的抗性机制。用 PBO 和 DEF 降低了对拟除虫菊酯的抗性，表明 P450 单加氧酶和酯酶参与了抗性的形成。用 PBO 和 DEF 抑制了残杀威的抗性，并且两种增效剂的共同给药导致抗性完全消除，表明 P450 单加氧酶和酯酶都参与其中。在所评估的 6 个德国小蠊田间菌株中，发现酯酶在毒死蜱抗性中起作用，而 P450 单加氧酶参与在 3 个菌株中。其他抗性机制，如 kdr 型和 Rdl 突变，分别导致对拟除虫菊酯和氟虫腈的抗性，也可能参与一些抗性水平不受增效剂影响的菌株。我们得出结论，新加坡田间德国小蠊种群中普遍存在杀虫剂抗性。
