Very distinctive, with a blue/green thorax and a ruby-coloured abdomen, these wasps are also known as Cuckoo Wasps, because of their habit of laying their eggs in the nests of other insects (often Mason Wasps) , (and er... they tell the time in Switzerland).
A first "3-named" insect for "Blue-Grey" - THE JEWEL WASP, THE CUCKOO WASP or THE RUBY-TAILED WASP. Take your pick!
NB. 05/07/07 At last! Finally saw the beautiful, tiny Jewel wasp again, and did manage to take its photo. Not easy. Its blowing a gale out there, and this fantastically coloured little insect just does not sit still...
Here are two of the best I took (the third is posted on the actual date - 05 July '07).