Flight season: Late March into September in South where it has two generations, may not appear until May in North where it probably only has one generation.
Flowers visited: Spring bees like dandelions, dead nettle and bilberry. Summer bees like thistles, devil’s bit scabious and brambles.
Nesting preferences: A parasite of the early bumblebee (Bombus pratorum), heath bumblebee (Bombus jonellus) and the bilberry bumblebee (Bombus monticola).
Status: Widespread and common over much of the UK.
Similar species: Fairly distinctive with their sharply curved tail if you can discern that it is a cuckoo bumblebee. Males are variable but
their normal form is distinctive with the red tip to the tail.
Description: These are small, fluffy cuckoo bees which have a sharply curved abdomen and a mix of yellow and black stripes. The males are quite variable creatures with a yellow collar, yellow midriff band before a white-ended abdomen tipped in red. They seem to really like woodland areas and the males will lek to impress and gain matings with females. The amorous males will lather themselves in plant oils to smell attractive to the females. The scent itself is a blend of citrus and musk, certainly worth smelling if you get the chance!
Where to see them: With the Vestal cuckoo bee (Bombus vestalis) I would say this is the cuckoo bee that I most frequently encounter in the valley, especially in woodland edge areas. It is very abundant on the valley tops near Nantyr where all of its host species are commonplace. It is this cuckoo bee and Bombus vestalis that you are most likely to see in your garden in the valley.
Forest cuckoo bee Bombus sylvestris
The sharply curved abdomen of Bombus sylvestris.