1. Wildflower plantings on farms have been shown to attract foraging wild bees, however, whether these added floral resources increase nesting densities of bees remains largely untested.
2. We placed nest boxes containing natural reeds at 20 fruit farms in Michigan. We then compared nesting densities between farms with and without wildflower plantings and analysed nest provisions to evaluate use of wildflower plantings for brood provisioning.
3. We found significantly greater nesting at farms with wildflower plantings, with only one out of 236 completed nests at a farm without a planting. The majority of nests were completed by Megachile pugnata, with a portion of nests completed by Osmia caerulescens.
4. We found that nesting bees collected pollen from only a subset of the available flowers in the wildflower plantings, with a strong preference for Centaurea maculosa, and Rudbeckia type pollens. While these species were found growing in the plantings, only Rudbeckia type species were seeded in the plantings.
5. This study provides evidence that wildflower plantings (though not only seeded species) are filling a critical resource gap for stem‐nesting bees in agricultural landscapes and likely support local populations.

中文翻译：

---

果场上的野花种植可提供花粉资源，并通过梗巢蜜蜂增加巢穴

1. 事实证明，农场上的野花种植吸引了野蜂的觅食，但是，这些增加的花卉资源是否会增加蜂的巢密度仍未得到测试。
2. 我们在密歇根州的20个水果农场中放置了装有天然芦苇的巢箱。然后，我们比较了有和没有野花种植的农场之间的筑巢密度，并分析了巢的供应情况，以评估野花种植在育雏中的使用。
3. 我们发现在有野花种植的农场中筑巢的数量要多得多，而在没有种植的农场中，只有236个完整的巢中只有一个筑巢。大部分的巢是由墨西哥Mega（Megamegale pugnata）完成的，有一部分的巢是由澳洲m（Osmia caerulescens）完成的。
4. 我们发现，筑巢蜂只从野花种植中的一部分可用花中采集花粉，其中强烈优先选择矢车菊（Centaurea maculosa）和黄金菊（Rudbeckia）型花粉。虽然发现这些物种在种植园中生长，但只有黄金菊类型的物种在种植园中播种。
5. 这项研究提供了证据表明，野花种植（尽管不仅是种子物种）正在填补农业景观中用于将蜜蜂筑巢的重要资源缺口，并有可能为当地居民提供支持。