Wildlife Watch: Ragwort

Ragwort.

There's a strange love-hate relationship with this biennial plant in the countryside. There are nineteen species to be found in the countryside and although this includes the likes of Oxford ragwort, brought here by the Victorians, you will most likely encounter Common ragwort. A native plant but one that is very much treated like a foreign invader with much time invested in removing it. The reason? Well it's pretty toxic, particularly to horses and cattle. This isn't much of an issue when it's alive as it has a bitter taste and grazers are unlikely to eat it unless the whole field is jaundiced with the plant or overgrazed. But when a field is cut for hay ragwort loses its bitterness whilst retaining its poisonous qualities.

Interestingly, a green dye can be made from its leaves and a yellow one from it's flowers.

However it is also quite an important plant from a wildlife point of view. It provides a habitat and food for at least 77 species of insect, 30 of which use ragwort exclusively, and it is a significant food source for 22 of the remainder. This includes some scarce species such as the Sussex emerald moth and Picture-winged fly but one of the best known is the Cinnabar moth.

This is a striking black and red day-flying moth. With red lines running along the outside its black forewings each splodged with two heavy red spots; its scarlet underwings peek though underneath. It's one of the most colourful moths we have in the UK and often mistaken as a butterfly as a result. Its caterpillars are equally distinctive, wasp-like with yellow and black stripes to warn predators of their poisonous nature (they absorb toxins from the plant)

Although it also uses the plant Groundsel as a foodplant for its caterpillars, ragwort is significant in it's survival as it provides toxins to make the caterpillar and moth unpalatable and is also a much larger plant for caterpillars to feed on, meaning more caterpillars survive.

Studies looking at Cinnabar moths have shown population declines due to the persecution of its foodplant ragwort so it may appear strange that many conservation organisation tasks are focused on removing what is a native and ecologically important plant.

Well it's largely so a hay crop can be taken. This is a way of managing levels of nutrients of grasslands. The hay itself can then either be used to provide food for a countryside organisation's livestock (as grazing is used to manage grasslands as well) or to sell to make some money. Ragwort can also be an issue if it takes over an area as it is a quick coloniser of bare ground and can take over and dominate some fields, this is more of an issue if next to other people's hay meadows as the seeds are wind dispersed.

Outside of these circumstances though I believe we should live and let live and leave ragwort and the insects that depend on it to get along with things out in the rest of the countryside. Sure, control ragwort where it's likely to be an issue but not look to eradicate it.