Data for: Abundance of short- and long-tongued bees, and their impact on red clover seed production in four cultivars grown across a large latitude range

The aim of this study was to investigate how short- and long-tongued bees (bumblebees and honeybees) affect seed production in different cultivars of red clover, focusing on tetraploid cultivars. The study includes two experiments. In the first one, data were collected from field trials at six different sites (belonging to Lantmännen) distributed in southern and northern Sweden over two years. The data from this experiment include seed yield, seed set, abundance of short- and long-tongued bees and seed-eating weevils, and plant traits (flower head density and number of florets per flower head) from one diploid and three tetraploid red clover cultivars. The second experiment was a cage study where seed yield from tetraploid red clover was evaluated from cages with different densities of the short-tongued bumblebee Bombus terrestris, and compared with seed yield from an open plot adjacent to the cages. This study was conducted in farmers' fields in southern and northern Sweden over two years.