Black Headed Cardinal Beetle
This cheery chap is a Black Headed Cardinal Beetle (Pyrochroa coccinea). They used to be rare in Surrey and Hampshire but now you’re much more likely to see one whizz past you in a blaze of scarlet. That’s what happened to me, and I tracked him until he landed and posed for me. His red-headed cousin is even more common.
They are predatory beetles, feeding on other insects. Their flattened larvae are adapted to live under the bark of trees. I saw this one at Home Farm wildlife reserve in Hampshire.