The descriptive text, below the map, is from the Cornish Red Data Book (2009). The map on this web page depicts the organisms distribution and shows the records made pre-2000 and those made since.
Range & Status
This species has much declined in the U.K., with the strongest populations found in South Wales, on Salisbury Plain, around the eastern Thames Estuary and some other locations on the south coast.
B. humilis is locally common on the north coast of Cornwall and in scattered locations on the south coast. Records point to some decline. The species is very similar to B. muscorum and on many sites in Cornwall both species fly together. There is a degree of unreliability in records for both species as a result of mis-identification.
Habitat & Ecology
This is a long-medium tongued, surface nesting species. It is found on high quality grassland and heathland mosaics. The species may be associated in Cornwall with Kidney Vetch Anthyllis vulneraria , which appears to be the most important forage for queens (Saunders, 2003). A variety of other forage is used by workers including Red Clover Trifolium pratense , Betony Stachys officinalis , Common Birds-foot-trefoil Lotus corniculatus , Common Knapweed Centaurea nigra and Wild Thyme Thymus polytrichus .
The major threat is the intensification of flower-rich habitat within 1 kilometre of suitable sites (most areas along the north Cornish coast). Also the under-grazing of coastal sites.
Protection and suitable management of coastal flower-rich grassland is required. The introduction of pollen and nectar margins or clover leys in agricultural landscape within 1km of known colonies would also be advantageous. This species is listed on the BAP middle list as a globally threatened/declining species (BSGR, 1995). BAP species (2007).
I.J. Bennallick, S. Board, C.N. French, P.A. Gainey, C. Neil, R. Parslow, A. Spalding and P.E. Tompsett. eds. 2009. Red Data Book for Cornwall and the Isles of Scilly. 2nd Edition.Croceago Press.
The Cornish Red Data Book Project was led by the Cornwall and Isles of Scilly Federation for Biological Recorders (CISFBR). The full text and species accounts (minus the maps) are available on the CISFBR website.