This is a long shot, especially as I have no photos, but you do occasionally have questions about wildlife from other countries.
I was working in East Africa, a few miles form Kampaly, Uganda, about 10 years ago and one day saw a dazzling green creature at the back of the house. It was so bright in the sunshine that at first I was dazzled, but eventually by squinting realised it must be some kind of wasp. It was fairly large, maybe about 3cm long, and the most shining bright emerald green I have ever seen.
Thank you, the Cockroach wasp looks more like what I remember, except it seemed to be green all over, not with red legs. Do you know what kind of size these wasps are? It was quite large and I'm almost sure more slender than the cuckoo wasp.
Acording to Wikipedia
The female is about 22 mm long; the male is smaller and lacks a stinger.
Thank you again. Fascinating!
I have marked this as correct because it seems unlikely that the exact identity of the wasp can be known after all this time and with only a vague description. On searching, it seems that other species of Ampulex are green all over, so it may have been one of those, unless I didn't notice the legs because of the whole thing being so bright and difficult to look at. The size and shape are about right and the colour was a clear green rather than blue-green like the cuckoo wasp picture.