At first glance, this caterpillar looks very attractive, as it is a pretty pale lilac colour, and you wonder which pretty moth or butterfly this will become. Unfortunately is will eventually turn into a black sawfly. This particular one, called Solomon's Seal Sawfly as the name suggests feeds on the Solomon's Seal plant and as you can see here, can be devastating and can completely defoliate these plants. Fortunately the plants can survive and grow again in the following year. Sawflies are so called because they cut into the leaves to lay their eggs.