In September 2009 I spotted this blue-gold insect through my bathroom window (Poole, Dorset, UK). I didn't want open the window for fear of scaring it away so the image is distorted by the glass.
I tried searching for it on Google but got nowhere and forgot about it until now when sorting through my stored photos. I would like to know what it is, because I've never seen anything like it before or since. Does anyone think they know what it is/was?
Possibly a chrysidid wasp - a group of wasps, not a single species.
Most of them have a 'metallic' colouration, in a variety of colours.
Common names include cuckoo wasp and ruby-tailed wasp.
None of those have the gold part in the right place, but there are many species...
(I don't think it is a beetle.)
Chrysididae seems like the most plausible possibility. It's unfortunate that there are so many varieties that it's unlikely a definite match with be found. I'm just glad it doesn't look like something that shouldn't be found in the UK, as I first suspected when I saw it. Thanks!
The antennae (from what I can make out in the first two photos) look like a fly's, not a wasp's. Maybe a hoverfly, like this one - http://www.insecte.org/forum/viewtopic.php?f=11&t=11406 - but that's just a suggestion.