Department of Biological Sciences, Rensselaer Polytechnic Institute , Troy, New York 12180, United States.
Department of Biological Sciences, University of Pittsburgh , Pittsburgh, Pennsylvania 15260, United States.
Environ Sci Technol. 2017 Jan 3;51(1):671-679. doi: 10.1021/acs.est.6b06055. Epub 2016 Dec 21.
Amphibian declines have been linked to numerous factors, including pesticide use and the fungal pathogen Batrachochytrium dendrobatidis (Bd). Moreover, research has suggested a link between amphibian sensitivity to Bd and pesticide exposure. We simultaneously exposed postmetamorphic American toads (Anaxyrus americanus), western toads (A. boreas), spring peepers (Pseudacris crucifer), Pacific treefrogs (P. regilla), leopard frogs (Lithobates pipiens), and Cascades frogs (Rana cascadae) to a factorial combination of two pathogen treatments (Bd, Bd) and four pesticide treatments (control, ethanol vehicle, herbicide mixture, and insecticide mixture) for 14 d to quantify survival and infection load. We found no interactive effects of pesticides and Bd on anuran survival and no effects of pesticides on infection load. Mortality following Bd exposure increased in spring peepers and American toads and was dependent upon snout-vent length in western toads, American toads, and Pacific treefrogs. Previous studies reported effects of early sublethal pesticide exposure on amphibian Bd sensitivity and infection load at later life stages, but we found simultaneous exposure to sublethal pesticide concentrations and Bd had no such effect on postmetamorphic juvenile anurans. Future research investigating complex interactions between pesticides and Bd should employ a variety of pesticide formulations and Bd strains and follow the effects of exposure throughout ontogeny.
两栖动物的数量减少与许多因素有关，包括农药的使用和真菌病原体蛙壶菌（Batrachochytrium dendrobatidis，Bd）。此外，研究表明两栖动物对 Bd 的敏感性与农药暴露之间存在联系。我们同时将变态后的美洲牛蛙（Anaxyrus americanus）、西部牛蛙（A. boreas）、春蛙（Pseudacris crucifer）、太平洋树蛙（P. regilla）、豹蛙（Lithobates pipiens）和瀑布蛙（Rana cascadae）暴露于两种病原体处理（Bd、Bd）和四种农药处理（对照、乙醇载体、除草剂混合物和杀虫剂混合物）的因子组合中 14 天，以量化存活率和感染负荷。我们没有发现农药和 Bd 对蛙类存活率的相互作用，也没有发现农药对感染负荷的影响。在接触 Bd 后，春蛙和牛蛙的死亡率增加，而西部牛蛙、牛蛙和太平洋树蛙的死亡率则取决于吻肛长。先前的研究报告了早期亚致死农药暴露对后期生命阶段两栖动物 Bd 敏感性和感染负荷的影响，但我们发现同时接触亚致死浓度的农药和 Bd 对变态后的幼年蛙类没有这种影响。未来研究应采用多种农药配方和 Bd 菌株，调查农药和 Bd 之间的复杂相互作用，并在整个个体发育过程中跟踪暴露的影响。
