24th June 2012:
Each year I find myself eagerly waiting for ragwort to appear, and it is popping up all over the marsh at the moment. Being a common weed, it grows on wasteland and pastures throughout the UK. It doesn’t tolerate regular soil cultivation, so it is rarely seen in arable fields.
Ragwort, a genus of the daisy family with marvellously yellow blooms, is one of my favourite wild plants. There are many people who won’t feel as I do; ragwort contains biocides such as alkaloids to deter animals from eating it. Unfortunately, ingested alkaloids can kill grazing animals. The poison accumulates in the liver, so small quantities can have a lethal effect over time.
Grazing animals don’t like to eat ragwort because of its bitter taste. However, wilted ragwort –when pulled up and left on the ground for a while, or when cut and baled during haymaking – can be less bitter and more likely to be consumed.
Animals might also eat ragwort when desperately short of fodder.
The cinnabar moth relies on ragwort for food and lays its eggs on the underside of the leaves. Their caterpillars absorb the bitter-tasting alkaloids present in ragwort to make themselves unpalatable to potential predators. In fact, ragwort is essential to the long-term breeding success of the cinnabar moth.
Ragwort is an important food source for at least 30 insect species and an important nectar source for:
30 species of solitary bees.
18 species of solitary wasps.
Many species of hoverfly.
At least 40 noctuid moths.
Seven nationally scarce insects/invertebrates are reliant on ragwort: three beetles, one fly and three micromoths), of which three species have Red Data Book status.