Abstract

Sedges (Cyperaceae) are commonly pollinated by wind, but some transitions from wind to insect pollination have been reported in tropical sedges. Despite being a temperate sedge, the pollination strategy of Rhynchospora alba may partly depend on insects, as suggested by its white-colored inflorescences. Here we quantify the contribution of insects to the reproductive fitness of R. alba as an exploration of the success of entomophily in temperate sedges. Honeybees and hoverflies seem to be the primary visitors of R. alba in the study site, and pollen of R. alba was recovered from the mouthparts and legs of the insects. Treatments excluding insects led to a lower reproductive fitness (regarding fruit weight and fruit viability) than those not excluding them. Therefore, insects seem to contribute significantly to the pollination of R. alba despite moderate morphological adaptation. We highlight the role of entomophily as an overlooked reproductive mechanism in cold-temperate sedges.

摘要

莎草（莎草科）通常通过风授粉，但在热带莎草中已经报道了一些从风授粉到昆虫授粉的转变。尽管是一种温带莎草，但如其白色花序所示， Rhynchospora alba的授粉策略可能部分依赖于昆虫。在这里，我们量化了昆虫对R. alba繁殖适应性的贡献，作为对温带莎草中昆虫学成功的探索。蜜蜂和食蚜蝇似乎是研究地点 R. alba 的主要访客，以及R. alba的花粉从昆虫的口器和腿中回收。排除昆虫的处理导致生殖适应性（关于果实重量和果实活力）低于不排除昆虫的处理。因此，尽管有适度的形态适应，昆虫似乎对R. alba的授粉有重大贡献。我们强调昆虫作为冷温带莎草中被忽视的繁殖机制的作用。