Dew Rebecca M, McFrederick Quinn S, Rehan Sandra M
Department of Biology, York University, Toronto, ON M3J 1P3, Canada.
Department of Entomology, University of California Riverside, Riverside, CA 92521, USA.
Insects. 2020 Aug 4;11(8):499. doi: 10.3390/insects11080499.
Bees collect pollen from flowers for their offspring, and by doing so contribute critical pollination services for our crops and ecosystems. Unlike many managed bee species, wild bees are thought to obtain much of their microbiome from the environment. However, we know surprisingly little about what plant species bees visit and the microbes associated with the collected pollen. Here, we addressed the hypothesis that the pollen and microbial components of bee diets would change across the range of the bee, by amplicon sequencing pollen provisions of a widespread small carpenter bee, , across three populations. was found to use a diversity of floral resources across its range, but the bacterial genera associated with pollen provisions were very consistent. , , , , and were among the top ten bacterial genera across all sites. uses both raspberry () and sumac () stems as nesting substrates, however nests within these plants showed no preference for host plant pollen. Significant correlations in plant and bacterial co-occurrence differed between sites, indicating that many of the most common bacterial genera have either regional or transitory floral associations. This range-wide study suggests microbes present in brood provisions are conserved within a bee species, rather than mediated by climate or pollen composition. Moving forward, this has important implications for how these core bacteria affect larval health and whether these functions vary across space and diet. These data increase our understanding of how pollinators interact with and adjust to their changing environment.
蜜蜂从花朵中采集花粉来哺育后代，在此过程中为我们的农作物和生态系统提供了至关重要的授粉服务。与许多人工养殖的蜜蜂品种不同，野生蜜蜂被认为其大部分微生物群落是从环境中获取的。然而，令人惊讶的是，我们对蜜蜂访问的植物种类以及与所采集花粉相关的微生物知之甚少。在这里，我们通过对广泛分布的小木匠蜂（Ceratina calcarata）三个种群的花粉供应进行扩增子测序，验证了蜜蜂食物中的花粉和微生物成分会因蜜蜂分布范围不同而发生变化这一假设。研究发现，Ceratina calcarata在其分布范围内利用多种花卉资源，但与花粉供应相关的细菌属非常一致。Acinetobacter、Bacillus、Enterococcus、Lactobacillus、Pantoea和Staphylococcus在所有地点的细菌属中排名前十。Ceratina calcarata使用悬钩子属（Rubus）植物和漆树属（Rhus）植物茎干作为筑巢基质，然而这些植物中的巢穴对宿主植物花粉并无偏好。不同地点植物与细菌共生的显著相关性存在差异，这表明许多最常见的细菌属具有区域性或临时性的花卉关联。这项涵盖整个分布范围的研究表明，育雏食物中存在的微生物在蜜蜂物种内是保守的，而非由气候或花粉成分介导。展望未来，这对于这些核心细菌如何影响幼虫健康以及这些功能是否因空间和食物而异具有重要意义。这些数据增进了我们对传粉者如何与不断变化的环境相互作用并适应环境的理解。
