Instituto de Investigación de la Cadena Láctea (IDICAL, INTA-CONICET), Instituto Nacional de Tecnología Agropecuaria, Estación Experimental Agropecuaria Rafaela (INTA E.E.A. Rafaela), Ruta 34 km 227, CP 2300, Rafaela, Santa Fe, Argentina.
Instituto Nacional de Tecnología Agropecuaria, Agencia de Extensión Rural San Pedro, Mitre 299, CP 2930, San Pedro, Buenos Aires, Argentina.
Res Vet Sci. 2022 Dec 5;150:10-21. doi: 10.1016/j.rvsc.2022.04.020. Epub 2022 Jul 2.
The aim of this research was to analyze and model the aptitude of temperate areas to support permanent populations of the cattle tick Rhipicephalus microplus, which is principally distributed in tropical and subtropical areas. This work integrated field-derived data of tick development with temperature and land-based models of tick spread in Argentina. The integrated analysis of the results suggest that approximately 31°S is the southern limit where R. microplus finds appropriate climatic conditions to be established permanently. The establishment of permanent populations of R. microplus south of this latitudinal threshold is currently restricted because the low temperatures in autumn and winter inhibit the development of its eggs, but the introduction of cattle infested with R. microplus from early spring to late summer in temperate areas could produce engorged females laying eggs that would originate viable larvae from late spring to winter. The comparison of the temperature-based maps of habitat suitability with those obtained considering the lands suitable for livestock grazing, clearly shows that the models based only on climatic variables overestimate the potential dispersal of the cattle tick. The outcomes of this study suggest that an increase of temperature in the months of autumn and winter around 2°-2.75 °C should be necessary for the establishment of permanent populations of R. micoplus in the region belonging to temperate areas. This would allow that a tick generation emerged in early spring due to the overwintering of eggs and larvae originated from females detached from cattle during autumn or early winter.
本研究旨在分析和模拟温带地区支持牛蜱（Rhipicephalus microplus）永久种群的适应性，该蜱种主要分布在热带和亚热带地区。本工作综合了阿根廷蜱传播的田间数据与温度和基于土地的模型，对结果进行了综合分析，结果表明，31°S 左右是 R. microplus 找到适宜气候条件以永久定居的最南端界限。由于秋季和冬季低温抑制其卵的发育，因此，在该纬度阈值以南建立 R. microplus 的永久种群目前受到限制，但是，从早春到晚夏，在温带地区引入感染了 R. microplus 的牛，可以产生饱血的雌性产卵，这些卵将从春末到冬季产生有活力的幼虫。将基于温度的适宜生境图与考虑到适合放牧牲畜的土地的那些图进行比较，清楚地表明，仅基于气候变量的模型高估了牛蜱的潜在扩散。本研究的结果表明，在秋季和冬季的几个月中，温度应增加 2°-2.75°C，以便在属于温带地区的区域中建立 R. micoplus 的永久种群。这将允许由于春季初从秋季或初冬从牛身上脱落的雌性产生的卵和幼虫越冬，而出现一代蜱虫。
