This bee is a male "cuckoo" vestal bumblebee (Bombus Psythirus vestalis); the female invades the nest of her host, kills the queen and lays her own eggs. Of the 54 species of bumblebee in the UK, it is one of 6 cuckoo bumblebees.

Photographed on 1st July 2006 at Totteridge Green, Northwest London.  Unfortunately the container in which it was temporarily held to allow inspection did not allow the camera to get close enough for a clear, sharp, "macro" photo.

(Photos by Liz Barrett for London Wildlife Trust)