Southern cuckoo bee, Bombus vestalis in Cuckfield, West Sussex, UK today

Southern cuckoo bee, Bombus vestalis

 This queen bumblebee is not collecting pollen or nectar for a nest.  She doesn't need to.

 She attacks nests of Buff-tailed bumblebees and lays her eggs there for the host workers to provide for.

Southern cuckoo bee, Bombus vestalis