The guys at BWARS think this is Bombus cryptarum but as y read in the info below without DNA it cant be recorded I suppose that is why the map is sparsely populated with records.
Possibly the most poorly-understood British bumblebee. It is very closely related to B. lucorum, but genetic studies show that it is a distinct taxa both in Britain and abroad.
Within the British Isles it is seemingly widespread in the north and west, and is especially frequent in Ireland. Unfortunately, it is scarcely distinguishable from lucorum in the field. It is said that the yellow collar has a characteristic dark S-shaped pattern in front of the wing bases, but the reliability of this has been questioned. So unless you can get your ‘Bombus lucorum’s’ DNA-tested, it unlikely that you will ever be able to record this species with confidence and many ‘lucorum’ records will need to be treated as ‘lucorum sensu lato’.