Abstract：
Bees provision most of the pollen removed from anthers to their larvae and transport only a small proportion to stigmas, which can negatively affect plant fitness. Though most bee species collect pollen from multiple plant species, we know little about how the efficiency of bees\' pollen transport varies among host plant species or how it relates to other aspects of generalist bee foraging behavior that benefit plant fitness, such as specialization on individual foraging bouts.
We compared the pollen collected and transported by three bee species for 46 co-occurring plant species. Specifically, we compared the relative abundance of pollen taxa in the individual bees\' scopae, structures where bees store pollen to provision larvae, with the relative abundance of pollen taxa on the rest of bees\' bodies, which is more likely to be transferred to stigmas.
Bees carried five times more pollen grains in their scopae than elsewhere on their bodies. Within foraging bouts, bees were relatively specialized in their pollen collection, but transported proportionally less pollen for the host plants on which they specialized. Across foraging bouts, two bee species transported proportionally less pollen for some of their host plants than for others, though differences didn\'t consistently follow the same trend as at the foraging bout scale.
Our results suggest that foraging-bout specialization, which is known to reduce heterospecific pollen transfer, also results in less-efficient pollen transport. Thus, bee foragers that visit predominantly one plant species may have contrasting effects on that plant\'s fitness.
We compared the pollen collected and transported by three bee species for 46 co-occurring plant species. Specifically, we compared the relative abundance of pollen taxa in the individual bees\' scopae, structures where bees store pollen to provision larvae, with the relative abundance of pollen taxa on the rest of bees\' bodies, which is more likely to be transferred to stigmas.
Bees carried five times more pollen grains in their scopae than elsewhere on their bodies. Within foraging bouts, bees were relatively specialized in their pollen collection, but transported proportionally less pollen for the host plants on which they specialized. Across foraging bouts, two bee species transported proportionally less pollen for some of their host plants than for others, though differences didn\'t consistently follow the same trend as at the foraging bout scale.
Our results suggest that foraging-bout specialization, which is known to reduce heterospecific pollen transfer, also results in less-efficient pollen transport. Thus, bee foragers that visit predominantly one plant species may have contrasting effects on that plant\'s fitness.
摘要：
目的：蜜蜂将从花药中去除的大部分花粉提供给幼虫，仅将一小部分花粉运输到柱头。这会对植物健康产生负面影响。尽管大多数蜜蜂物种从多种植物物种收集花粉，我们对蜜蜂花粉运输的效率在寄主植物物种之间的变化知之甚少，或者它如何与多面手蜜蜂觅食行为的其他方面相关，这些方面有利于植物的健康，比如对个体觅食回合的专业化。
方法：我们比较了三种蜂种收集和运输的46种共生植物的花粉。具体来说,我们比较了单个蜜蜂中花粉类群的相对丰度，蜜蜂储存花粉以提供幼虫的结构，其他蜜蜂身体上的花粉类群相对丰富，更有可能被转移到柱头。
结果：蜜蜂在其范围内携带的花粉粒是其身体其他地方的5倍。在觅食的回合中，蜜蜂的花粉采集相对专业，但是为他们专门研究的寄主植物运输的花粉比例较少。在觅食的比赛中，两种蜜蜂为它们的寄主植物运输的花粉比例少于其他蜜蜂，尽管差异并不总是遵循与觅食回合规模相同的趋势。
结论：我们的结果表明，觅食对专业化，已知可以减少异源花粉转移，也导致花粉运输效率较低。因此，主要访问一种植物物种的蜜蜂觅食者可能会对该植物的适应性产生相反的影响。本文受版权保护。保留所有权利。
方法：我们比较了三种蜂种收集和运输的46种共生植物的花粉。具体来说,我们比较了单个蜜蜂中花粉类群的相对丰度，蜜蜂储存花粉以提供幼虫的结构，其他蜜蜂身体上的花粉类群相对丰富，更有可能被转移到柱头。
结果：蜜蜂在其范围内携带的花粉粒是其身体其他地方的5倍。在觅食的回合中，蜜蜂的花粉采集相对专业，但是为他们专门研究的寄主植物运输的花粉比例较少。在觅食的比赛中，两种蜜蜂为它们的寄主植物运输的花粉比例少于其他蜜蜂，尽管差异并不总是遵循与觅食回合规模相同的趋势。
结论：我们的结果表明，觅食对专业化，已知可以减少异源花粉转移，也导致花粉运输效率较低。因此，主要访问一种植物物种的蜜蜂觅食者可能会对该植物的适应性产生相反的影响。本文受版权保护。保留所有权利。
