Table S1 species list.xlsx from Introduced bees (<i>Osmia cornifrons</i>) collect pollen from both coevolved and novel host-plant species within their family-level phylogenetic preferences

Studying the pollen preferences of introduced bees allows us to investigate how species use host-plants when establishing in new environments. <i>Osmia cornifrons</i> is a solitary bee introduced into North America from East-Asia for pollination of Rosaceae crops such as apples and cherries. We investigated whether <i>O. cornifrons</i> (i) more frequently collected pollen from host-plant species they coevolved with from their geographic origin or (ii) prefer hosts-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 <i>O. cornifrons</i> disproportionately, yet not exclusively, collected pollen from their native range. Plants in the family Rosaceae were their most preferred pollen hosts, where they differentially collected species native to East-Asia, Europe, or North America depending on the landscape. Our results suggest that while <i>O. cornifrons</i> more frequently collect pollen of East-Asian origin, the collection of pollen from novel species within their phylogenetic familial affinities can facilitate pollinator establishment. This phylogenetic preference highlights the effectiveness of <i>O. cornifrons</i> 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.

探究引入型蜂类的花粉偏好，可助力解析物种在全新环境中定殖时如何利用寄主植物。毛角壁蜂（*Osmia cornifrons*）是一类从东亚引入北美、用于为苹果、樱桃等蔷薇科（Rosaceae）作物授粉的独居蜂类。本研究旨在探究毛角壁蜂的花粉采集偏好：究竟是（i）更倾向于采集其原生分布区协同演化的寄主植物花粉，还是（ii）偏好与原产地无关的特定分类群植物？为解答该问题，本研究采用花粉元条形码（pollen metabarcoding）技术，对不同景观中巢穴内幼虫食物团的花粉种类与相对丰度进行了检测；这些巢穴所在景观的东亚与非东亚植物丰度各不相同。研究结果表明，毛角壁蜂虽并非仅采集原生分布区花粉，但显著倾向于选取原生分布区的花粉来源。蔷薇科植物是其最偏好的花粉寄主，且毛角壁蜂会根据所在景观的不同，差异化采集东亚、欧洲或北美原生的蔷薇科植物花粉。本研究结果提示：尽管毛角壁蜂更常采集东亚起源的花粉，但选取与其系统发育亲缘关系相近的外来物种花粉，可助力该传粉者实现种群定殖。这种系统发育偏好性，也印证了毛角壁蜂作为跨地理起源多种蔷薇科作物传粉者的有效性。本研究结果还暗示：非本土植物的全球化分布，或可降低其协同演化传粉者在原生分布区之外实现归化的难度。