Unidad Operativa de Vectores y Ambiente (UnOVE). Centro Nacional de Diagnóstico e Investigación en Endemo-Epidemias. Administración Nacional de Laboratorios e Institutos de Salud Dr. Carlos Malbrán (CeNDIE- ANLIS Malbrán). Santa María de Punilla, Córdoba, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina.
Institut de Recherche pour le Développement (IRD), UMR INTERTRYP IRD-CIRAD, University of Montpellier, F-34398 Montpellier, France.
Acta Trop. 2023 Sep;245:106976. doi: 10.1016/j.actatropica.2023.106976. Epub 2023 Jun 22.
In vector control terms, insecticide resistance is the development of the capacity, of an insect population, to tolerate doses of an insecticide that are lethal to most individuals in a typical population of the same species. The genetic changes that determine resistance may have adaptive costs in the resistant phenotype or, conversely, may result in an adaptive advantage when compared to susceptible insects in the environment without insecticides. Triatoma infestans is one of the main vectors of Trypanosoma cruzi in the southern cone of South America. High insecticide resistance in T. infestans was detected in Argentina in Salta and Chaco provinces. The objective of this study was to determine the possible morphometric changes in wings, heads, and the antennal phenotype of deltamethrin-resistant T. infestans (RR) males and females compared to susceptible insects (SS), evaluating its implication in adaptive processes such as olfactory capacity, dispersion, and probability of colonizing new habitats, among others. Nine type I landmarks were marked on wings, 5 type II landmarks on heads, and 10 antennal sensilla were counted on 106 adults of both sexes (resistant and susceptible from first and second laboratory generations). Morphological divergence was observed between the two groups (RR and SS). The RR insects showed smaller sizes of wings and heads and shape compatible with lower dispersal potential and different active dispersal behaviors. Antennae also revealed sensory simplification in RR and divergence between RR and SS, although more marked in females. This study characterizes for the first time T. infestans RR and SS through wings, heads, and antennae. The results suggest a lower dispersive potential in resistant insects and the differences described lay the foundations for the identification of a resistance biomarker in triatomines.
在病媒控制术语中，昆虫抗药性是指昆虫种群能够耐受通常在同一物种的典型种群中对大多数个体致命的杀虫剂剂量的能力。决定抗药性的遗传变化在抗性表型中可能具有适应成本，或者与环境中没有杀虫剂的敏感昆虫相比，可能导致适应优势。布氏锥虫是南锥体南美洲的主要锥虫传播媒介之一。在阿根廷的萨尔塔省和查科省发现了布氏锥虫的高杀虫剂抗性。本研究的目的是确定与敏感昆虫（SS）相比，对溴氰菊酯具有抗性的雄性和雌性布氏锥虫（RR）的翅膀、头部和触角表型可能发生的形态变化，评估其在嗅觉能力、扩散和有性生殖能力等适应过程中的意义。在 106 只成虫（第一代和第二代实验室的 RR 和 SS）的翅膀上标记了 9 个 I 型标志，在头部上标记了 5 个 II 型标志，在触角上标记了 10 个触角感觉器。观察到两组（RR 和 SS）之间存在形态差异。RR 昆虫的翅膀和头部尺寸较小，形状与较低的扩散潜力和不同的主动扩散行为相适应。触角也显示出 RR 的感觉简化和 RR 与 SS 之间的差异，尽管在雌性中更为明显。本研究首次通过翅膀、头部和触角对 RR 和 SS 的布氏锥虫进行了特征描述。结果表明，抗性昆虫的扩散潜力较低，描述的差异为三锥虫抗性生物标志物的鉴定奠定了基础。
