Departamento de Ecología, Genética y Evolución, Facultad de Ciencias Exactas y Naturales, Laboratorio de Eco-Epidemiología, Universidad de Buenos Aires, Buenos Aires, Argentina.
Instituto de Ecología, Genética y Evolución (CONICET-IEGEBA), CONICET-Universidad de Buenos Aires, Buenos Aires, Argentina.
Med Vet Entomol. 2023 Dec;37(4):834-844. doi: 10.1111/mve.12689. Epub 2023 Sep 2.
Pyrethroid-resistance is an emergent trait in populations of various insect species. For Triatoma infestans (Klug, 1834) (Heteroptera: Reduviidae), the major vector of Chagas disease in the southern part of South America, hotspot areas of pyrethroid-resistance have recently been found in the Chaco Province of Argentina. Resistant condition can reduce fitness of individuals in the absence of insecticide exposure, that is, fitness costs. We evaluated the existence of developmental and/or reproductive costs in T. infestans collected from two areas of pyrethroid-resistance in Chaco Province, Argentina. Three toxicological groups were defined from field-collected insects: susceptible (survival <20%), moderately resistant (survival between 20% and 80%) and highly resistant (survival >80%). Cohorts of the three toxicological groups were followed-up to study life cycle and reproductive parameters. Additionally, we parameterized matrix population growth models. First and IV nymphal stages of the resistant groups exhibited a longer stage duration than susceptible ones. The reproductive days and hatching success showed significant lower values revealing reproductive costs for the resistant groups. Matrix analysis showed lower population growth rates for the resistant groups. Our results support developmental and reproductive costs for pyrethroid-resistant individuals. This trait could be interpreted as lower population recovery ability for pyrethroid-resistant individuals compared to susceptible insects after alternative vector control actions.
拟除虫菊酯抗性是各种昆虫种群中出现的一种紧急特征。对于在南美洲南部地区传播恰加斯病的主要媒介三带喙库蚊（Klug，1834）（半翅目：红蝽科），最近在阿根廷查科省发现了拟除虫菊酯抗性的热点地区。在没有杀虫剂暴露的情况下，抗性条件会降低个体的适应性，即适应成本。我们评估了在阿根廷查科省两个拟除虫菊酯抗性地区采集的三带喙库蚊是否存在发育和/或生殖成本。从野外采集的昆虫中定义了三个毒理学组：敏感（存活率<20%）、中度抗性（存活率在 20%到 80%之间）和高度抗性（存活率>80%）。对三个毒理学组的群体进行了后续跟踪，以研究生命周期和生殖参数。此外，我们还参数化了矩阵种群增长模型。抗性组的第一和第四龄若虫阶段的持续时间比敏感组长。繁殖天数和孵化成功率显示出显著较低的值，表明抗性组存在生殖成本。矩阵分析显示，抗性组的种群增长率较低。我们的结果支持拟除虫菊酯抗性个体存在发育和生殖成本。与敏感昆虫相比，这种特征可以解释为在替代病媒控制措施后，拟除虫菊酯抗性个体的种群恢复能力较低。
