The Red-tailed Bumblebee queens and workers are all black except for a fox-red "tail" (end of abdomen).
The Red-tailed male has a similar appearance to the females with the addition of a canary yellow bar across the upper thorax and yellow hair on the face.
Sometimes the male has another slight yellow bar across the lower thorax and even one on the abdomen; sometimes males have no yellow bars at all.
Above right shows the size comparison of the queen redtail and the mating male.
Red-tailed workers with full pollen baskets.
Other red-tailed Bumblebees include the Early Bumblebee (Bombus pratorum)
whose males have more yellow on their shoulders and abdomen,
the Red-shanked Carder (also called Red-tailed Carder, Bombus ruderarius) which has a ginger tail and shorter, squat abdomen and the Hill Cuckoo Bumblebee (Bombus rupestris) which has a stepped abdomen and parasitises the Red-tails' nests.
There are also small hoverfly mimics of the male and the female Red-tailed Bumblebee.