I spent an hour going through my guidebooks on British caterpillars and butterfly life cycles but couldn’t find a match for this little critter, found on a stem of Common broom (Cytisus scoparius) growing on the side of the Aberbargoed spoil tip. So, I put a query on Twitter, tagged a couple of friendly experts, and within five minutes I had an answer. It wasn’t a Lepidoptera larva at all – this is the larva of the Broom leaf-beetle (Gonioctena olivacea) (click on this link to the UK Beetles website to read more). Of course, now I’m going to have to go back to see if I can find the adult beetle, which is apparently active between April and late summer, and which I’ve never seen.