"Rod Craddock" wrote
But yes, Small Heath looks a much better bet.

That Caterpillar isn't in any of our books. I only ever see them up in
those hills, usually a week or 2 earlier than this. Usuallly look fully
fed and behaviour suggesting looking for somewhere to pupate.

I suspect a Moth of the family Arctiidae (like a Dingy Footman) most if not
all have hairy caterpillars. Finding a photo is difficult though.

--
Regards
Bob
In Runnymede, 17 miles West of London