Centro de Investigaciones de Plagas e Insecticidas (CONICET-CITEDEF), Juan Bautista de La Salle 4397, B1603ALO, Villa Martelli, Provincia de Buenos Aires, Argentina.
J Med Entomol. 2012 Nov;49(6):1355-60. doi: 10.1603/me12070.
Triatoma infestans (Klug, 1834) (Hemiptera, Reduviidae) is the main vector of Chagas disease in the southern cone South America. Chemical control to the vectors appears to be the best option to reduce the incidence of the disease. However, since 2002, high resistance to insecticides that correlated with field control failures was detected in T. infestans from Argentina and Bolivia. In this paper, we analyzed three T. infestans populations whose pyrethroid-resistance had been recently detected, and we defined at least three resistant profiles according to the toxicological and biochemical characteristics of the studied resistant populations. The resistance profiles were identified as Ti-R1, Ti-R2, and Ti-R3, corresponding to the Argentinean Acambuco, and the Bolivians Entre Ríos and Mataral. Ti-R1 exhibited nymphs and eggs with medium resistance level to deltamethrin (RR = 32.5 and 28.6; respectively). Pyrethroid-esterases played a relevant role in deltamethrin resistance. Ti-R2 exhibited nymphs with high resistance to deltamethrin (RR = 173.8) and low resistance to fipronil (RR = 12.4). Pyrethroid-esterases were involved in resistance. Moreover, eggs showed medium resistance level to deltamethrin (RR = 39.1). Ti-R3 had nymphs with low resistance to deltamethrin (RR = 17.4), and medium resistance to fipronil (RR = 66.8). Pyrethroid-esterases showed increased activity, and eggs possessed low resistance to deltamethrin (RR = 8.4). The characterization of the resistance to pyrethroid in these T. infestans populations from Argentina and Bolivia do not permit the generalization of three forms of resistance profile. So far as we appear to know, the forms of mechanisms and their frequencies reported here are selected independently, so additional sites might well show additional combinations of resistance mechanisms and their frequencies.
布氏田鳖（Klug，1834）（半翅目，红蝽科）是南美洲南部锥体中查加斯病的主要传播媒介。化学控制媒介似乎是降低疾病发病率的最佳选择。然而，自 2002 年以来，在阿根廷和玻利维亚的 T. infestans 中检测到与田间控制失败相关的对杀虫剂的高度抗性。在本文中，我们分析了三个最近检测到对拟除虫菊酯具有抗性的 T. infestans 种群，并根据研究的抗性种群的毒理学和生化特性定义了至少三种抗性谱。抗性谱被鉴定为 Ti-R1、Ti-R2 和 Ti-R3，分别对应于阿根廷的 Acambuco、玻利维亚的 Entre Ríos 和 Mataral。Ti-R1 表现出对溴氰菊酯具有中等抗性的若虫和卵（RR = 32.5 和 28.6）。拟除虫菊酯酯酶在溴氰菊酯抗性中发挥了重要作用。Ti-R2 表现出对溴氰菊酯的高抗性（RR = 173.8）和对氟虫腈的低抗性（RR = 12.4）。拟除虫菊酯酯酶参与了抗性。此外，卵对溴氰菊酯表现出中等抗性水平（RR = 39.1）。Ti-R3 对溴氰菊酯的若虫具有低抗性（RR = 17.4），对氟虫腈具有中等抗性（RR = 66.8）。拟除虫菊酯酯酶显示出增加的活性，卵对溴氰菊酯具有低抗性（RR = 8.4）。对来自阿根廷和玻利维亚的这些 T. infestans 种群对拟除虫菊酯的抗性的特征化不允许对三种抗性谱形式进行概括。就我们所知，迄今为止报告的这些机制形式及其频率是独立选择的，因此其他部位很可能显示出额外的抗性机制及其频率的组合。
