Partitioning pollination services to faba bean (Vicia faba L.) between managed honeybees and wild bees

Animal pollination of crops is an important ecosystem service provided especially by managed honeybees and wild bees, but the relative importance of these taxa for crop pollination remains debated. Faba bean (Vicia faba L.) is a grain legume crop grown worldwide for food and feed which is partially dependent on insects for pollination. I determined the relative contribu-tion of honeybees and wild bees to faba bean pollination. Visitation rates and foraging behaviours of pollinators were measured in a total of 20 faba bean fields over two years (10 fields per year) in Sweden, and the bean mass per flower visit for different pollinator taxa was quantified in a field experiment which was repeated over two years in a single site. By combining informa-tion on visitation rates, foraging behaviours and gains in bean mass from single visits to flowers, I estimate that 47% of insect pollination services to faba bean is delivered by honeybees, 40% by short-tongued bumblebees, 6% by long-tongued bumble-bees and 8% by solitary bees. I conclude that both managed honeybees and wild bees, especially short-tongued bumblebees, contribute substantially to faba bean pollination in Sweden, and I recommend faba bean farmers to manage for both these polli-nator taxa.& COPY; 2023 The Author(s). Published by Elsevier GmbH on behalf of Gesellschaft for okologie. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/)