I brought this handsome caterpillar home from the allotment today on a groundsel plant. I had to look it up on the web to find out what it was. Apparently it's the caterpillar of the cinnabar moth, which is grey and red. It was imported to tackle the problem weed ragwort which is poisonous to livestock , as it devours the plant. It's amazing what I'm learning through this site.
Great close up. I remember as a child, a field near our house was covered in tall yellow flowered plants and they in turn used to be covered in these caterpillers. Thanks for the info.