A day trip to Suffolk ended with a chance encounter with an aggregation of female Colletes hederae, new to Britain in 2001, digging in the bailey of Orford Castle at about 6:15pm when it was turning cold and the sun had already set on the location. (You can read more about the species here http://www.bwars.com/index.php?q=content/colletes-hederae-mapping-project). I've still to find it in Beds but I know it was first(?) seen in the Sandy area a couple of years ago.
Only had my toy camera with me so not great shots: