Nontarget Effects of Host-Specific Biocontrols: Direct and Indirect Effects of Biocontrols that Subsidize Native Consumers

众所周知，食物网中消费者的间接影响在生态系统中很重要，但这一知识尚未很好地融入应用领域，例如生物制剂的杂草控制。 引入外来昆虫作为生物防治剂是控制入侵植物越来越常见的策略，并且只要控制剂具有宿主特异性，就被认为是生态安全的。 然而，即使是宿主特异性物质也可能被本地物种消耗，从而影响食物网的其他部分。 这项研究将研究外来瘿蝇对鹿鼠种群的间接影响，这种外来瘿蝇是为了控制入侵草种而引入的，鹿鼠是北美西部许多草原上昆虫和种子的主要捕食者，也是辛诺布尔汉坦病毒的主要载体，这种病毒会导致人类致命的汉坦病毒肺综合征。 研究目标是通过从草地上清除瘿蝇来进行扰动实验，以量化瘿蝇补贴对鹿鼠种群的直接影响，并测量间接影响，包括汉坦病毒的流行、种子捕食、本土植物的发芽和补充以及本土昆虫的丰度。 这项研究将提供一种更有效地从生物防治计划中过滤潜在危险昆虫的方法，从而推动生物防治领域的发展。 此外，汉坦病毒信息将分发给地区卫生当局，以帮助制定管理指南，以减少与瘿蝇介导的汉坦病毒流行率增加相关的人类健康风险。

The indirect effects of consumers in food webs are known to be important in ecological systems, but this knowledge has not been well integrated into applied fields such as weed control by biological agents. The introduction of exotic insects as biological control agents is an increasingly common strategy employed for the control of invasive plants and is thought to be ecologically safe so long as the control agents are host-specific. However, even host-specific agents may be consumed by native species and so impact the rest of the food web. This research will examine the indirect effects of an exotic gall fly, introduced to control an invasive grass species, on populations of deer mice that are key predators of insects and seeds in many western North American grasslands, and are the primary vectors for the Sin Nombre hantavirus, which causes the deadly hantavirus pulmonary syndrome in humans. Research goals are to conduct a perturbation experiment by removing gall flies from grassland plots in order to quantify the direct effect of gall fly subsidies on deer mouse populations, and measure indirect effects, which include the prevalence of the hantavirus, seed predation, germination and recruitment of native plants, and abundance of native insects. This research will advance the field of biological control by providing a means of more effectively filtering potentially hazardous insects from biocontrol programs. Additionally, hantavirus information will be disseminated to regional health authorities to help develop management guidelines to reduce human health risks associated with gall fly-mediated increases in the prevalence of hantavirus.