Bug

Before lunch I walked round the garden looking for bugs to take for a blip.
I came across two of these bugs who then mated in front of my eyes!
I have no idea what it is, and an internet search hasn't helped. They are the size of a small ladybird. If anyone knows what it is I would be very grateful!
I do hope they aren't pests as I imagine that very soon there will be several more about!