In the United Kingdom, where the plant is native, ragwort provides a home and food source to at least 77 insect species. Thirty of these species of invertebrate use ragwort exclusively as their food source and there are another 22 species where ragwort forms a significant part of their diet.
English Nature identify a further 117 species that use ragwort as a nectar source whilst travelling between feeding and breeding sites, or between metapopulations. These consist mainly of solitary bees, hoverflies, moths, and butterflies such as the small copper butterfly (Lycaena phlaeas). Pollen is collected by solitary bees.