Here is a list of British bumble bees, with Latin and common names where known. Included is Bombus hypnorum - not originally a UK bumble bee species, but a relatively recent arrival in Britain.
Click on the links to read more about the species (this is currently work in progress).
Read more about cuckoo bumble bees.
The reasons are complex, however, habitat is a key issue. Generally, the more adaptable bumble bee species in terms of habitat, food and nesting requirement, have remained more common.
Bumble bees requiring very specific habitats, foraging and food have suffered greatly due to habitat destruction. For example, those relying on grasslands and wildflower meadows have suffered due to changing land management practices, the industrialisation of farming, destruction of hedgerows etc.
In addition to habitat loss, all bees face the challenge of pesticide use across large areas of land.
Benton, Ted. Bumblebees: The Natural History & Identification of the Species Found in Britain. Collins 2006.