Predators and mutualists influence the exclusion of aphid species from natural communities
Predators and mutualists influence the exclusion of aphid species from natural communities
复制标题
捕食者和互利共生者影响着蚜虫物种被排除在自然群落之外
作者：
Christine B. Müller;H. Godfray
摘要我们调查了为什么两种蚜虫（Aphis jacobaeae和Brachycaudus cardui）在一个研究地点非常罕见，尽管它们在周围地区很丰富。该研究地点包含许多常见的蚜虫物种，我们测试了假设，该社区的蚜虫捕食者在该领域排除了失踪的物种。两种蚜虫物种的殖民地人工启动在实验场所，并分配到四个治疗之一：控制;地面捕食者排除;总捕食者排除，和提供互利蚂蚁。分析了两个衡量群体性能的指标：寿命和累积蚜虫密度。殖民地自然下降，在夏末，但控制殖民地消失得很快，而殖民地保护所有捕食者生存时间最长。保护殖民地免受地面掠食者的性能是中间的。我们未能说服蚂蚁照料A。Jacobaeae B的菌落。有蚂蚁参与的cardui比对照组和排除地面捕食者的cardui表现得更好，但不如排除所有捕食者的cardui。我们的结论是，在研究地点的两种蚜虫的情况下，居民捕食者社区的影响，并通过互利共生的可用性。
Abstract We investigated why two species of aphids (Aphis jacobaeae and Brachycaudus cardui) were very rare in a study site despite their abundance in the surrounding area. The study site contained many common species of aphid and we tested the hypothesis that the community of aphid predators in the field excluded the missing species. Colonies of the two aphid species were artificially initiated in the experimental site and allocated to one of four treatments: control; ground predator exclusion; total predator exclusion, and provision of mutualist ants. Two measures of colony performance were analysed: longevity and cumulative aphid density. Colonies decline naturally in late summer but control colonies disappeared very quickly while colonies protected from all predators survived the longest. The performance of colonies protected from just ground predators was intermediate. We failed to persuade ants to tend A. jacobaeae. Colonies of B. cardui attended by ants performed better than controls and those with ground predators excluded, but not as well as those with all predators excluded. We conclude that the absence of the two species of aphid in the study site is influenced by the resident predator community, and by the availability of mutualists.