Schmid-Hempel Regula, Eckhardt Michael, Goulson David, Heinzmann Daniel, Lange Carlos, Plischuk Santiago, Escudero Luisa R, Salathé Rahel, Scriven Jessica J, Schmid-Hempel Paul
ETH Zürich, Institute of Integrative Biology (IBZ), ETH-Zentrum CHN, Universitätsstrasse 16, CH-8092, Zürich, Switzerland.
Biological and Environmental Sciences, School of Natural Sciences, University of Stirling, Stirling, FK9 4LA, UK.
J Anim Ecol. 2014 Jul;83(4):823-37. doi: 10.1111/1365-2656.12185. Epub 2014 Jan 29.
The Palaearctic Bombus ruderatus (in 1982/1983) and Bombus terrestris (1998) have both been introduced into South America (Chile) for pollination purposes. We here report on the results of sampling campaigns in 2004, and 2010-2012 showing that both species have established and massively expanded their range. Bombus terrestris, in particular, has spread by some 200 km year(-1) and had reached the Atlantic coast in Argentina by the end of 2011. Both species, and especially B. terrestris, are infected by protozoan parasites that seem to spread along with the imported hosts and spillover to native species. Genetic analyses by polymorphic microsatellite loci suggest that the host population of B. terrestris is genetically diverse, as expected from a large invading founder population, and structured through isolation by distance. Genetically, the populations of the trypanosomatid parasite, Crithidia bombi, sampled in 2004 are less diverse, and distinct from the ones sampled later. Current C. bombi populations are highly heterozygous and also structured through isolation by distance correlating with the genetic distances of B. terrestris, suggesting the latter's expansion to be a main structuring factor for the parasite. Remarkably, wherever B. terrestris spreads, the native Bombus dahlbomii disappears although the reasons remain unclear. Our ecological and genetic data suggest a major invasion event that is currently unfolding in southern South America with disastrous consequences for the native bumblebee species.
古北区的红腹熊蜂（1982/1983年引入）和意大利熊蜂（1998年引入）均已被引入南美洲（智利）用于授粉。我们在此报告2004年以及2010 - 2012年采样活动的结果，结果表明这两个物种都已立足并大规模扩展了它们的分布范围。尤其是意大利熊蜂，其扩散速度约为每年200公里，到2011年底已抵达阿根廷的大西洋海岸。这两个物种，尤其是意大利熊蜂，都感染了原生动物寄生虫，这些寄生虫似乎随着引入的宿主传播，并扩散到本地物种。通过多态微卫星位点进行的遗传分析表明，意大利熊蜂的宿主种群在基因上具有多样性，这正如一个大规模入侵的奠基种群所预期的那样，并且通过距离隔离形成了结构。从基因上看，2004年采样的锥虫寄生虫——熊蜂短膜虫的种群多样性较低，且与后来采样的种群不同。当前的熊蜂短膜虫种群高度杂合，并且也通过与意大利熊蜂的遗传距离相关的距离隔离形成了结构，这表明后者的扩张是该寄生虫的一个主要结构形成因素。值得注意的是，无论意大利熊蜂扩散到哪里，当地的达尔氏熊蜂都会消失，尽管原因尚不清楚。我们的生态和遗传数据表明，南美洲南部目前正在发生一场重大的入侵事件，这对当地的熊蜂物种造成了灾难性后果。
