Keys and general biology are found in Sladen (1912), Free & Butler (1959), Alford (1975) and Prŷs-Jones & Corbet (1991). This species is very closely related to Bombus muscorum but is more southerly in its distribution. B. humilis has undergone a major decline in its distribution, with most remaining populations being on extensive, although sometimes narrow, areas of coastal grasslands. This decline seems to be closely linked to the intensification of farming.
Intermittently present along the southern and western coasts of England and Wales, reaching furthest north on the Lleyn Peninsula and Anglesey. There are a few inland populations, most notably on Salisbury Plain, Wiltshire. In common with other bumblebees, relatively large areas of suitable habitat, in the order of ten square kilometres, are required to maintain viable populations. Widespread in Europe, as far north as southern Scandinavia, but declining in many places (von Hagens, 1994; Westrich, 1989). Also found throughout central Asia (Løken, 1973).