The Ruderal Bumblebee (Bombus Ruderatus) is the UK’s biggest variety of bumblebee. It is only found in the south of England and is sadly rare due to the huge decline which happened throughout the 20th century. However, the future could be looking up for this species as, in some areas, the population of them could be recovering slightly.
They usually nest in colonies of 150 workers at most, in old rodent or small mammal burrows that are underneath land that is abundant in flowers like Clover, Comfrey, Borage, Nettle, Knapweed, Vetches and Viper’s Bugloss.
The queens, males and workers all sport the same appearance — yellow and black thorax, yellow stripe at the bottom of the abdomen and a tail that is pure white.
This species can produce melanic individuals too. In short, they are entirely black bumblebees. While other British bumblebee types can be melanic, they are less common so if you spot an all-black bumblebee, they are probably Ruderal bumblebees.
The Bombus Ruderatus is extremely reminiscent of the Garden bumblebee (Bombus hortorum), so much so that some individuals are impossible to distinguish!
Typically speaking, the male Garden bumblebees consist of mandibles that have black hair around them, whereas the Ruderal bumblebee has ginger. Plus, the Ruderal has an even length of hair all over them, whereas the Garden variety (Bombus hortorum) is a lot scruffier. You may not realise this fact unless you witness them in the same vicinity though.
However, bear in mind that the females are far more difficult to tell apart. If you are desperate to find out, you will need to measure their faces. The Garden bumblebee (Bombus hortorum) has a shorter face than the Ruderal bumblebee (Bombus ruderatus) but you will have to get pretty close to figure this out!