Flight season: Late March to September.
Flowers visited: B. hortorum has a extremely long tongue (average of 12mm for workers) and so it has a close association with flowers with a deep corolla tube. Workers visit a huge variety but can be found in great numbers on plants such as Wood Sage who’s corolla tube is too long for many other bees and so B. hortorum has very little competition.
Nesting preferences: Nests can be found both underground in old rodent burrows, in dense vegetation and, occasionally, in places such as an old bird’s nest.
Status: Common in Britain.
Parasites: Barbut's cuckoo bumblebee, Bombus barbutellus. Also a few species of Conopid fly, like Physocephla rufipes.
Similar species: The ruderal bumblebee, B. ruderatus, (B. ruderatus has shorter fur) and the heath bumblebee, B. jonellus, (this species has a shorter face).
Description: The garden bumblebee has the longest tongue of any British bee. This makes it an incredibly important pollinator for flowers such as Sage which have long corolla tubes. It has the same banding pattern as the heath bumblebee, B. jonellus, but is massively more abundant and its face is much longer (at least 3/4 of the length of an eye in the malar gap). The garden bumblebee has quite a shaggy coat, far more so than its much rarer cousin the Ruderal bumblebee Bombus ruderatus which otherwise it can easily be confused with. However, Bombus ruderatus has not been recorded from the valley (or anywhere nearby) and so there should be little confusion.
Where to see them: As the name suggests they are a common garden bumblebee which can be readily seen. They especially like flowers with long nectar tubes and so can be seen in large numbers around sage and foxgloves as competition from other bumblebees with shorter tongues is minimised.
Garden Bumblebee Bombus hortorum
The difference in face length between the garden bumblebee, Bombus hortorum, (L) and the heath bumblebee, Bombus jonellus (R).