I think that the eggs are those of the Green Dock Beetle Gastrophysa viridula, a Chrysomelid. It has been everywhere on dock around Langport during the last 4 summers.

Pictures of the adults at:http://www.bioimages.org.uk/html/T98663.HTM

I think that the caterpillar is a young Mottled Umber - the picture below is a fully-grown specimen.

However it could be Dotted Border although I've never seen one. The photo in Porter doesn't help much.

The trap here in Langport has beeen generally poor over the last few days but firsts for the year of Green Carpet, Waved Umber and Bright-line Brown-eye.