Laboratorio de investigación en Triatominos (LIT), Centro de Referencia de Vectores (CeReVe), Coordinación de Vectores, Ministerio de Salud y Desarrollo Social, Santa María de Punilla, Córdoba, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina.
Laboratorio de investigación en Triatominos (LIT), Centro de Referencia de Vectores (CeReVe), Coordinación de Vectores, Ministerio de Salud y Desarrollo Social, Santa María de Punilla, Córdoba, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina.
Acta Trop. 2020 Apr;204:105345. doi: 10.1016/j.actatropica.2020.105345. Epub 2020 Jan 16.
In Argentina, the main vector of Chagas disease is Triatoma infestans (Klug, 1834). In recent years, the presence of T. infestans was reported in human dwelling after spraying with pyrethroids in several locations in Argentina. The presence of these insects can be attributed, among other factors, to colonization by bugs from sylvatic or peridomestic populations or to the evolution of resistance to insecticides. In both cases, the dispersal of insects is a determining factor. The aim was to determinate the interaction of dispersal with feeding, food resource and resistance to insecticides. Three nutritional states were obtained with the number of feeds (NF) offered (0, 1 or 2). The resistant females were evaluated only with NF1. The experimental arena was 10 m long and contained two shelters. Groups of 30 virgin females of each NF were released in one of the shelters and were able to move during 3 days/nights. Females without possibility of dispersal were the controls. Results showed that the individuals dispersed mainly walking regardless of the number of feeds, the presence of food resource and toxicological phenotype. This type of dispersal presented energy costs in susceptible individuals but not in resistant ones. The numbers of feeds that determined low nutritional states showed greater dispersal and activity associated with the shelter. The presence of a food source had an effect on the dispersal capacity and this depended on the number of feeds. There was a decrease in the dispersal in individuals with one feeding and an absence of response in fasted individuals and with two feeds. On the other hand, a lower dispersal tendency were found in resistant females compared to susceptible females, suggesting that resistance to deltamethrin is associated with adaptive costs.
在阿根廷，克氏锥虫病的主要传播媒介是 Triatoma infestans（Klug，1834）。近年来，在阿根廷的几个地点，在用拟除虫菊酯喷洒后，在人类住所中发现了 T. infestans。这些昆虫的存在可以归因于多种因素，包括来自森林或半野外种群的昆虫的殖民化，或对杀虫剂的抗性进化。在这两种情况下，昆虫的扩散都是一个决定性因素。目的是确定扩散与取食、食物资源和对杀虫剂的抗性的相互作用。通过提供的饲料数量（NF）获得了三个营养状态（0、1 或 2）。只有 NF1 评估了抗性雌性。实验场地长 10 米，包含两个避难所。每组 30 只 NF 的处女雌性被释放到其中一个避难所中，并能够在 3 天/夜期间移动。没有扩散可能性的雌性作为对照。结果表明，个体主要通过行走扩散，而与饲料数量、食物资源和毒理学表型无关。这种扩散类型在敏感个体中会带来能量成本，但在抗性个体中则不会。确定低营养状态的饲料数量越多，与避难所相关的扩散和活动就越多。食物源的存在对扩散能力有影响，这取决于饲料的数量。在只喂食一次的个体中，扩散减少，而在禁食个体和喂食两次的个体中则没有反应。另一方面，与敏感雌性相比，抗性雌性的扩散倾向较低，这表明对溴氰菊酯的抗性与适应成本有关。
