This is a good reason for "untidy" bee-friendly natural areas of our gardens.
An enemy of the Common carder bee is the Cuckoo bee below, which lays its eggs inside Carder bee nests which are then fed by the host workers.
This looks like Bombus campestris, the Field cuckoo bee.
More info' at http://www.bwars.com/index.php?q=bee/apidae/anthophora-furcata
The fourth bee was Buff-tailed bumblebee, which I didn't bother to photograph as it is so common this year.A "wild garden" is an endless source of fascination for nature lovers like me.
And a rich source of material for my nature talks. See www.peterlovetttalks.co.uk