Earlier today I went over Ampthill Park in order to search for Harvest Mouse nests. I could only spare a few hours and, in the event, my plans changed when I came across two Xylota sylvarum hoverflies spending their time in the vicinity of an old fallen tree stump. It's the first chance that I've had to photograph this attractive hoverfly. This individual got used to me over a period of time and even perched on my jeans & boots!
There were also several of these attractive wasps flying about amongst the bramble leaves:
Thanks to Tim Strudwick of the BWARS Newsgroup who has identified it as Mellinus arvensis. An internet search reveals it to be a wasp that is likely to be seen over the next few months searching various bushes in a hunt for flies. It places up to a dozen of these in a near-vertical sandy burrow that can be some 40cm long! Jeremy Early has conducted an interesting study of some of his local individuals here.