Even an iPhone shot is good enough to identify this beetle, spotted on one of the tree guards in the picnic clearing in early May.
It’s obviously a cardinal beetle and it’s got a red head so we’re guessing Pyrochroa serraticornis, which is a properly descriptive name for once (‘notched horns’). Antennae are supposed to be pectinate in male, serrate in female. No, me neither, but looking at the picture copied below from Bugwood Wiki and the photos on the WCG website its seems pretty clear to me that our young chap is a pectinate (B vs C).
Its easier to find than most beetles, for being bright red but also because it hangs around in the open – presumably its colour acts as a warning to birds that would otherwise have it for breakfast. The Wildlife Trusts website tells us that the adults are up and about May to July and can often be found sunbathing on flowers or tree trunks. They are predators and feed on other insects flying around the flowers on which they are perched. The larvae are flattened in appearance, which enables them to live under loose bark where they feed on the larvae of other insects.