Data from: Evolved pesticide tolerance influences susceptibility to parasites in amphibians

Because ecosystems throughout the globe are contaminated with pesticides, there is a need to understand how natural populations cope with pesticides and the implications for ecological interactions. From an evolutionary perspective, there is evidence that pesticide tolerance can be achieved via two mechanisms: selection for constitutive tolerance over multiple generations or by inducing tolerance within a single generation via phenotypic plasticity. While both mechanisms can allow organisms to persist in contaminated environments, they might result in different performance tradeoffs including population susceptibility to parasites. We have identified 15 wood frog populations that exist along a gradient from a close to agriculture and high, constitutive pesticide tolerance to a far from agriculture and inducible pesticide tolerance. Using these populations, we investigated the relationship between evolutionary responses to the common insecticide carbaryl and host susceptibility to the trematode Echinoparyphium lineage 3 and ranavirus using lab exposure assays. For Echinoparyphium, we discovered that wood frog populations living closer to agriculture with high, constitutive tolerance experienced lower loads than populations living far from agriculture with inducible pesticide tolerance. For ranavirus, we found no relationship between the mechanism of evolved pesticide tolerance and survival, but populations living closer to agriculture with high, constitutive tolerance experienced higher viral loads than populations far from agriculture with inducible tolerance. Land-use and mechanisms of evolved pesticide tolerance were associated with susceptibility to parasites, but the direction of the relationship is dependent on the type of parasite, underscoring the complexity between land use and disease outcomes. Collectively, our results demonstrate that evolved pesticide tolerance can indirectly influence host-parasite interactions and underscores the importance of including evolutionary processes in ecotoxicological studies.由于全球各类生态系统均遭受农药污染，学界亟需明确自然种群如何应对农药胁迫，以及这一过程对生态相互作用的影响。从进化生物学视角来看，已有研究表明，农药耐受可通过两种机制实现：一是历经多代选择获得组成型耐受（constitutive tolerance），二是通过表型可塑性（phenotypic plasticity）在单一代际内诱导产生耐受。尽管两种机制均可帮助生物在污染环境中存续，但它们可能引发不同的性能权衡（performance tradeoffs），其中包括种群对寄生虫的易感性差异。本研究选取了沿环境梯度分布的15个木蛙（wood frog）种群，其分布范围从紧邻农业区、具备高组成型农药耐受的生境，延伸至远离农业区、仅能通过诱导产生农药耐受的生境。依托这些种群，我们通过实验室暴露实验（lab exposure assays），探究了针对常用杀虫剂西维因（carbaryl）的进化响应，与宿主对吸虫（trematode）棘口吸虫（Echinoparyphium）谱系3以及蛙病毒（ranavirus）的易感性之间的关联。针对棘口吸虫谱系3，研究发现，紧邻农业区、具备高组成型耐受的木蛙种群，其寄生虫载量显著低于远离农业区、仅具诱导型农药耐受的种群。针对蛙病毒而言，我们未发现进化获得的农药耐受机制与宿主存活率之间存在关联，但紧邻农业区、具备高组成型耐受的种群，其病毒载量显著高于远离农业区、仅具诱导型耐受的种群。土地利用方式与进化获得的农药耐受机制均与宿主寄生虫易感性相关，但这种关联的方向因寄生虫类型而异，这凸显了土地利用与疾病结局之间关系的复杂性。综合来看，本研究结果表明，进化获得的农药耐受可间接影响宿主-寄生虫相互作用，同时凸显了在生态毒理学（ecotoxicological）研究中纳入进化过程的重要性。