Irish faba beans (Fabales: Fabaceae) depend on wild bumblebee pollination for marketable yields

Abstract

Quantifying the contributions of insect pollinators to crops provides insight into how pollination services should be managed and protected into the future. Faba bean, Vicia faba var minor (Linneaus), is a widely grown crop globally that can benefit from pollinator visitation, but only from species that are morphologically compatible with the plant's long-corollae flowers. Here, we rank insect pollinators in terms of their potential importance to faba bean pollination and quantify the economic value of pollination for Irish faba beans. Our findings demonstrate that bee pollination contributes significantly to the pod set of faba beans, and, consequently, the crop's production value. We find that pollination services account for almost half of Ireland's total faba bean market value, with the pollinator contribution estimated at almost €4,000,000 per year. We estimate that, relative to other pollinators, wild bumblebees contribute to approximately 70% of the economic value of pollination services in faba bean fields, driven mainly by the contributions of a long-tongued bumblebee species, Bombus hortorum (Linneaus; Hymenoptera: Apidae). Based on these results, we suggest that B. hortorum populations be encouraged on farmland through appropriate management to ensure the continued delivery of pollination services to Irish faba beans.