Hoplia philanthus. I can’t bring myself to call it a Welsh chafer until someone can explain how it came by the name.

@bugmanjones Chafer comes from the Old English word for beetle "Ceafor", which literally means gnawer but was applied to herbivorous beetles.

I assume the Welsh is because its found in Wales?

The only chafer that’s is at all Welsh is Amphimallon falleni @ubi I’m sticking to scientific names.
@bugmanjones I have no experience with European beetles, so I'll go with your opinion.