Interesting article on how Common Ragwort (Senecio jacobaea) divides conservationists and landowners, and the importance of the plant for insect diversity:

http://www.theguardian.com/environment/2014/jul/31/pulborough-brooks-sussex-shining-blossoms-divide-opinions

Cinnabar moth caterpillars on ragwort. Photograph: © Alamy