Studying the pollen preferences of introduced bees allows us to investigate how species use host-plants when establishing in new environments. Osmia cornifrons is a solitary bee introduced into North America from East Asia for pollination of Rosaceae crops such as apples and cherries. We investigated whether O. cornifrons (i) more frequently collected pollen from host-plant species they coevolved with from their geographic origin, or (ii) prefer host-plant species of specific plant taxa independent of origin. To address this question, using pollen metabarcoding, we examined the identity and relative abundance of pollen in larval provisions from nests located in different landscapes with varying abundance of East-Asian and non-Asian plant species. Our results show that O. cornifrons collected more pollen from plant species from their native range. Plants in the family Rosaceae were their most preferred pollen hosts, but they differentially collected species native to East Asia, Europe, or North America depending on the landscape. Our results suggest that while O. cornifrons frequently collect pollen of East-Asian origin, the collection of pollen from novel species within their phylogenetic familial affinities is common and can facilitate pollinator establishment. This phylogenetic preference highlights the effectiveness of O. cornifrons as crop pollinators of a variety of Rosaceae crops from different geographic origins. Our results imply that globalization of non-native plant species may ease the naturalization of their coevolved pollinators outside of their native range.

通过研究引进蜜蜂的花粉偏好，我们可以研究在新环境中建立物种时物种如何利用寄主植物。Osmia cornifrons是从东亚引入北美的一种蜜蜂，用于对蔷薇科植物（如苹果和樱桃）进行授粉。我们调查了O.cornifrons（i）是否更频繁地从与其地理起源一起进化的寄主植物物种中收集花粉，或者（ii）偏爱特定植物分类单元的寄主植物物种，而与起源无关。为了解决这个问题，我们使用花粉元条形码技术，研究了位于东亚和非亚洲植物物种丰富度不同的不同景观中的巢中幼虫提供的花粉的身份和相对丰富度。我们的结果表明O. cornifrons从其本地范围的植物物种中收集了更多的花粉。蔷薇科中的植物是它们最喜欢的花粉寄主，但根据地貌，它们以不同的方式收集东亚，欧洲或北美洲的本地种。我们的结果表明，虽然O. cornifrons经常收集东亚起源的花粉，但从其系统发生家族亲和力中的新物种中收集花粉是很常见的，并且可以促进授粉媒介的建立。这种系统发育偏好突出了O. cornifrons的有效性作为来自不同地理起源的多种蔷薇科作物的作物传粉者。我们的结果表明，非本地植物物种的全球化可能会简化其共同进化的授粉媒介在其本地范围以外的自然化。