The problem with a white-tailed common social bumblebee with single yellow bands on thorax and abdomen in summer is that it could either be a terrestris male or a lucorum queen. The hind tibia on terrestris looks rather pollen-basket like, but in fact you don't need to catch these to tell them apart. The male terrestris has buff hairs on the hind tibia, whereas the female lucorum (and terrestris) has black ones). This view shows them well, and I think they are an excellent and less-well-known field character to look for.Note also the thin buff/yellow line between the black and white which may also be a terrestris male field character.Pleased this is in the 200-view club. so that this field character becomes better-known.