Solomon's Seal Sawfly

Spotted this lot merrily munching their way through the Solomon's Seal recently - a lot of the plants had been stripped of their leaves entirely. Concerned that they'd move on to decimate more plants, Martin started picking off handfuls of the things (literally - see below!).  

Having looked them up online though, it turns out they are the larvae of the Solomon's Seal sawfly and only eat Solomon's Seal.  Since the plants grow back every Spring, I don't suppose they're really much of a problem after all - hopefully we didn't devastate the population too much!