This is the mullein moth caterpillar feasting on - would you believe it - mullein. From what I can discover in the reference books we've got here its the caterpillar that is interesting and the moth itself is completely "ordinary" if that can describe a moth. I haven't actually been able to find a picture of the moth at all. If you look carefully you will see the spider on the rose bud. Not remarkable for its size but only because it is almost completely white.