I am glad that the hon. Gentleman has clarified that point. Although all hon. Members have constituents who are worried about the welfare of their horses and other animals, we also have constituents who are very keen on butterflies and moths, and we would probably upset them if there were any suggestion of their extinction.
Ragwort is important to biodiversity in this country. It is vital to the survival of the cinnabar moth. So we begin to discover how the plague started in the late 1980s. In fact, 1988 was a particularly good year for the cinnabar moth. What happened was that the cinnabar moth caterpillar munched far too much ragwort. Although that sounds like a good thing, the following year, there was nothing for the caterpillars to eat, the moths did not lay their eggs and the predator population of cinnabar moth caterpillars plummeted, so we began to see an increase in common ragwort in the late 1980s.
We have to look seriously at the effect of biological controls on ragwort to try to re-establish the cinnabar moth, the existence of which is precarious in Britain at the moment. It is simply not reaching sustainable levels, so apart from all the other methods that can be considered to control common ragwort—systemic pesticides, digging out the roots and so on—the cinnabar moth is crucial to the argument. Some companies are now looking at such biological controls.
A few years ago, some of us laughed at the idea of buying nematodes to use as a biological method of controlling slugs in our gardens, but they are now commonly used. That method is more natural and it is also very effective. I hope that we can enlist the support of the cinnabar moth to contribute to reducing equine deaths.
One cinnabar moth caterpillar can eat a ragwort flower in about three minutes. When the moth lays its eggs and the caterpillars hatch, the brood will demolish the flowers on a plant in a day, thus getting rid of the seeds that could be released into the wind. Those caterpillars will consume about 30 plants before they turn into moths. As the hon. Member for Ryedale said, those plants can produce between 150,000 and 200,000 seeds, so we can see the effect that the cinnabar moth could have on beginning to reduce the ragwort population to a level where it is less of a threat to equines, bovines and other species, while still contributing to the biodiversity of the United Kingdom's environment away from where animals are kept. I would not wish to see the plant totally destroyed. It looks wonderful away from pasture and paddocks, where it is no risk to animals.