Bombus rupestris – Dartmoor

Status (in Britain only)
Listed as a Notable (B) species Falk (1991) [now known as Scarce (Nb)], but becoming more abundant.
Although its host is a frequent species in gardens, most records relate to areas of unimproved grasslands
Flight period
The females do not usually come out of hibernation until late May or June and can be seen searching for host nests during the latter month. The new generation of adults emerges in late July or August
Nesting biology
In early summer, each female Bombus rupestris enters an established nest of B. lapidarius where it attacks and kills the resident queen. The parasite then establishes itself as the “queen” in the nest with its complement of B. lapidarius workers. The female B. rupestris lays female, and then male eggs that will be reared by the B. lapidarius workers. Once egg laying is completed, the female B. rupestris dies in the nest.
Flowers visited
Mainly plants in the families Apiaceae, Lamiaceae and Asteraceae…. BWARS