Dataset for paper: The best wildflowers for wild bees

Data for paper published in the Journal of Insect Conservation Dec 2019. The dataset shows results of a survey conducted in 2018, where foraging visits by different wild bees on different species of wildflower were recorded to species level.<br><b>Abstract</b>Governmental agri-environment schemes (AES) aim to improve pollinator abundance and diversity on farmland by sowing wildflower seed mixes. These often contain high proportions of Fabaceae, particularly <i>Trifolium</i> (clovers), which are attractive to some bumblebee species, but not to most of the ~240 solitary bee species in the UK. Here we identify wildflowers that are attractive to a greater range of wild bee species. Forty-five wildflower species being farmed for commercial seed production on a single farm were surveyed for native bees. Bee walks were conducted through discrete wildflower areas from April until August in 2018. The results indicate that including a range of Apiaceae, Asteraceae, and Geraniaceae in seed mixes would cater for a wide diversity of bee species. A total of 14 wildflower species across nine families attracted 37 out of the 40 bee species recorded on the farm, and accounted for 99.7% of all visitations. Only two of these 14 species are included in current AES pollinator mixes. Unexpectedly, few visits were made by bumblebees to <i>Trifolium</i> spp. (0.5%), despite their being considered an important food source for bumblebees, while <i>Anthyllis vulneraria</i> and <i>Geranium pratense</i> were highly attractive. For solitary bees, <i>Crepis capillaris</i>, <i>Sinapsis arvensis</i>, <i>Convolvulus arvensis</i> and <i>Chaerophyllum temulum</i> were amongst the best performing species, none of which are usually included in sown flower mixes. We suggest that the standard ‘pollinator’ mixes used in AES might be updated to include some of these wildflower species, and trialled as seed mixes on farmland.