Ecological Effects of a Host Range Expansion by a Weevil Imported for Biological Control

小行星9615299 研究人员建议测量花头象鼻虫（Rhinocyllus conicus）的影响，释放外来蓟的生物控制，对本地植物和与它们相关的昆虫。 实验将测量本地蓟的开花时间对象鼻虫影响的影响， 象鼻虫对本地蓟种子生产的影响，以及引入象鼻虫的上级竞争能力是否是本地昆虫种群下降的原因。 预期成果包括：文件的程度和影响的喂养外来象鼻虫对两种本地植物在大平原上，植物生长模式的作用象鼻虫的使用和影响的评估，并确定转移主机使用故意引入昆虫的直接生态后果。 这项研究将是第一个通过实验评估故意引入美国以控制外来杂草的昆虫对本地宿主植物的非故意取食的生态后果。 越来越多地提倡杂草生物防治作为除草剂的环境替代品。 然而，很少有数据可用于评估引入外来昆虫的生物控制计划的环境风险。 这项研究将提供重要的数据，这种后果时，发生转移，从而对潜在的生态风险与传统的生物控制杂草。 这些信息应该证明是有用的，在未来的尝试，以控制外来杂草入侵。

9615299 LOUDA The investigators propose to measure the impact of the flowerhead weevil (Rhinocyllus conicus), released for biological control of exotic thistles, on native plants and the insects associated with them. Experiments will measure the effects of the timing of flowering by native thistles on the impact of weevils, the effect of the weevil on seed production of native thistles, and whether superior competitive ability of the introduced weevil is responsible for the population decline of native insects. The expected outcomes include: documentation of the extent and impact of the feeding by the exotic weevil on two native plants in the upper Great Plains, assessment of the role of plant growth patterns on weevil use and impact, and determination of the direct ecological consequences of shifting host use by a deliberately introduced insect. The study will be the first to experimentally assess the ecological consequences of unintended feeding on native host plants by an insect deliberately introduced into the USA to control exotic weeds. Biological control of weeds is increasingly advocated as an environmental alternative to herbicides. Yet, few data are available with which to evaluate environmental risks of introducing exotic insects in biological control programs. The study will provide important data on such consequences when transference occurs and, thus, on potential ecological risks associated with classical biological control of weeds. Such information should prove useful in future attempts to control invasive exotic weeds.