Originally Posted by Roger Morris
No, this is Leucozona lucorum - the scutellum is yellowish and the shape is wrong for C. illustrata
Hi Roger, and thanks for putting me right! [Sigh of relief] at last, we have a real expert on the forum!
Although I am gaining knowledge all the time it is obvious [as on this occasion] that I have much to learn. For example I have not knowingly come across a 'dark' L. lucorum before but now it's been pointed out the other features you mention become more obvious.