Photos are not always good for identification purposes but I think you are right about it being B. vestalis. This takes over the nest of its host B. terrestris. The only other potential i/d is for B. bohemicus, which is a cuckoo in the nest of B.lucorum. [Said to be a more northerly species]. I have only ever seen 1 x B. bohemicus in my VC55 garden years ago. All the other regulars [in large numbers] are B. vestalis. If you get close enough, check out the relative lengths of antennal segments 3 and 5 [see “Bumblebees” by Ted Benton, Page 307. Hope this helps.
Thank you, that’s very helpful. I have Benton’s book on loan so I will take a look.
Thanks both and to urbanbumble for the expert advice.
Technically you can’t separate B vestalis and bohemicus from photos but certainly vestalis is more common in some areas, particularly south of the UK.
I would bet on B vestalis! There may be some black hairs in the collar or am I imagining them!