Individual study: Bumblebees Bombus spp. use forage plants sown on field margins as a pollen source, at Manor Farm, Eddletorpe, North Yorkshire, England
Carvell C., Westrich P., Meek W.R., Pywell R.F. & Nowakowski M. (2006) Assessing the value of annual and perennial forage mixtures for bumblebees by direct observation and pollen analysis. Apidologie, 37, 326-340
Some bumblebee species Bombus have dramatically declined in Europe, and modern intensive agricultural practices are a suspected cause. This study assesses the value of three seed mixtures, available as options under the UK Environmental Stewardship Scheme, in providing pollen resources for foraging bumblebees at Manor Farm, Eddlethorpe, North Yorkshire, England.
Five 30 m x 6 m plots of each of three seed mixtures were sown on the margin of a large arable field, on 17 April 2001. The mixtures were: two perennial grass and wildflower mixes - ‘basic’ with three herbaceous species (black knapweed Centaurea nigra, bird’s-foot trefoil Lotus corniculatus and red clover Trifolium pratense) and ‘diverse’, with 18 herbaceous species - and a mix of annual cover crops including borage Borago officinalis, fodder radish Raphanus sativus and yellow-blossomed clover Melilotus officinalis.
Total bumblebee abundance was highest on annually sown plots. Short-tongued bumblebee species B. terrestris, B. lucorum and B. pratorum strongly preferred the annual seed mixture. Long-tongued bumblebee species Bombus hortorum and B. pascuorum preferred the perennial seed mixtures, but were not more abundant on the ‘diverse’ than the ‘basic’ mix. Six common bumblebee species were recorded.