Ecological and Evolutionary Impacts of Pesticides on Non-target Organisms: A Focus on Amphibians

该项目的重点是生态环境在确定农药对自然界非目标生物的影响方面所起的作用。该提案的总体目标是确定长期暴露于农药对两栖动物的生态和进化影响，两栖动物是全球保护关注的群体。 研究的第一个目的是检验暴露时间对农药暴露致死率的影响。 为了这个初步目标，八种两栖动物的幼虫将受到西维因，一种常见的杀虫剂，不同的时间长度。 本研究的第二个目的是确定生物和非生物生态环境如何与农药暴露相互作用，影响适合度性状。实验室研究表明，pH值的变化和捕食者线索的存在可以使农药更加致命，但这些戏剧性的影响是否发生在自然条件下尚不清楚。此外，毒理学的重点一直是致命的影响，较少关注非致命的影响，如个人特征的变化。然而，我们从生态学研究中了解到，性状变化可能对个体如何与其他物种相互作用产生巨大影响。为了实现第二个目标，研究人员将饲养幼两栖动物在池塘围隔生态系统和研究农药，pH值和捕食者的线索对个人生存和个人特征的相互影响。 据预测，包括在生态条件的自然差异将产生重大影响的农药诱导的性状和农药引起的死亡率。 本研究的第三个目的是研究两栖动物对农药抗性的进化。有大量的文献在许多害虫物种的进化阻力，但在非目标物种的进化阻力的调查显着缺乏和两栖动物的进化阻力的研究似乎是不存在的。为了研究两栖动物进化抗性的过程，研究人员将采取三管齐下的方法，研究不同历史农药暴露的种群之间的抗性差异，农药抗性的遗传性，以及多代选择实验，以确定是否两栖动物暴露于农药最终可以进化出对农药的抗性。预期在自然种群中存在农药抗性的遗传变异，并且暴露于农药将有利于两栖动物抗性的进化。总的来说，这项研究预计将表明，生态环境是至关重要的了解农药在非目标生物的生态和进化的影响。

This project focuses on the role that ecological context plays in determining the impact of pesticides on non-target organisms in nature. The overall goal of this proposal is to determine the ecological and evolutionary effects of long-term exposure to a pesticide on amphibians, a group of global conservation concern. The first objective of the research is to examine effects of exposure time on lethality of pesticide exposure. For this preliminary objective, eight species of larval amphibians will be subjected to carbaryl, a common pesticide, for varying lengths of time. The second objective of this study is to determine how the biotic and abiotic ecological environment interacts with pesticide exposure to affect fitness traits. Laboratory studies suggest that changes in pH and the presence of predator cues can make pesticides much more deadly, but it is unknown if these dramatic effects occur under natural conditions. Additionally, the toxicological focus has been on lethal effects with less of a focus on nonlethal effects such as changes in individual traits. However, we know from ecological studies that trait changes can have dramatic effects on how an individual interacts with other species. To achieve the second objective, the investigator will rear larval amphibians in pond mesocosms and examine the interacting impacts of pesticides, pH, and predator cues on individual survival and individual traits. It is predicted that the inclusion of natural differences in ecological conditions will have a substantial impact on the pesticide-induced traits and pesticide-caused mortality. The third objective of this study is to examine the evolution of pesticide resistance in amphibians. There is a vast literature on evolved resistance in many pest species, but investigations of evolved resistance in non-target species are noticeably lacking and studies of evolved resistance in amphibians appear to be nonexistent. To investigate the process of evolved resistance in amphibians, the investigator will take a three-pronged approach that examines differences in resistance among populations that differ in historical pesticide exposure, the heritability of pesticide resistance, and a multi-generation selection experiment to determine if amphibians exposed to pesticides can eventually evolve resistance to pesticides. The expectation is that there is genetic variation in pesticide resistance in natural populations and exposure to pesticides will favor the evolution of resistance in amphibians. Collectively, this research is expected to show that ecological context is critical for understanding the ecological and evolutionary impacts of pesticides in non-target organisms.