Empidine dance flies pollinate the woodland geranium as effectively as bees

Most flowering plants species rely on insects for pollination, a successful mutualism allowing them to reproduce over wide areas while flower-visitors are rewarded with food. This association is so conspicuous in the case of bees that other groups of potential pollinators, especially flies, have long been underestimated. However, visitors are not always pollinators. While the importance of flies in plant-visitor networks is now acknowledged, their pollination effectiveness has hardly been investigated. In this study, we assessed the pollination effectiveness of Geranium sylvaticum flower-visitors using single visits seed-set experiments, in a subalpine meadow where flies are predominant. We found that: (i) empidine dance flies were the most frequent visitors of G. sylvaticum; (ii) a single visit by an empidine dance fly produced the same average number of seeds as a visit by a bee; (iii) large pollinators were more efficient than small pollinators irrespectively of their identity. As a ...

绝大多数显花植物依赖昆虫完成传粉，这是一种高效的互利共生关系：植物得以在广阔区域内繁衍，而访花昆虫则能获取食物作为回报。由于蜜蜂在这类共生关系中的表现极为突出，其他类群的潜在传粉者（尤其是蝇类）长期以来被低估了其作用。不过，访花者并非总能成为有效的传粉者。尽管如今学界已认可蝇类在植物-访花者网络（plant-visitor networks）中的重要性，但针对其传粉效率的研究仍几乎空白。本研究在蝇类占主导的亚高山草甸中，采用单花单次访花坐果实验（single visits seed-set experiments），评估了林生老鹳草（Geranium sylvaticum）访花者的传粉效率，并得到以下结果：（i）舞虻亚科（Empidine）舞蝇是林生老鹳草最频繁的访花类群；（ii）单只舞虻亚科舞蝇的单次访花所产生的平均种子数量，与蜜蜂访花后的平均种子数量相当；（iii）体型较大的传粉者的传粉效率显著高于小型传粉者，且与其类群身份无关。As a ...