Horse owners in Bradford, who are at their wits' end in an endless battle against the spread of the deadly ragwort weed, are now considering importing a species of caterpillar to eradicate it .

Clusters of striking, bright yellow ragwort flowers are becoming an increasing problem in fields and verges around the district.

Although it brings a touch of colour to the countryside, the innocent-looking plant fills horse and cattle owners with dread as it is one of the most common causes of livestock plant poisoning in Britain.

If digested by animals it can destroy the liver and eventually lead to death.

Occupiers of land containing ragwort can be prosecuted under the Weeds Act 1959 by the Department for Environment, Food and Rural Affairs (DEFRA) if they do not prevent it from spreading.

And the weed is such a problem that the British Horse Society holds an annual Root Out Ragwort Week.

But Bradford horse owners believe they might have found the answer to their problems.

The cinnabar moth lays its larva under ragwort leaves and when the eggs hatch the caterpillars eat the leaves stopping it seeding.

With each plant producing up to 150,000 seeds traditional methods of treating the weed can be a never-ending and back-breaking process.

Horse owner, Sheena Beaumont, pictured, of Old Road, Thornton, Bradford, heard about using caterpillars to control the weed from a friend in Barnsley.

Mrs Beaumont, 37, has had a ragwort problem for two summers in the field she has rented near her home where she keeps a number of horses she looks after with health problems.

Sheena is constantly trying to get rid of the weed, which seeded before she had the field, but said all the tactics she has tried have failed.

"Last year we resorted to trying to pull it all up by the roots but it is back this year. We have tried everything, including using an old piece of farm machinery, known as an Allenside, to clear the field."

"I am now thinking of getting hold of the caterpillar and attempting to introduce it to the field," she said.

The idea, which has been used in Canada and New Zealand to attempt to reduce ragwort there, is attracting attention elsewhere in the district.

Sue Nutter, owner of Otley Silver Mill Riding and Trekking Centre, Otley, said: "If there was evidence that introducing caterpillars reduced the problem I would happily try them out."

A DEFRA spokesman said the department was aware of the method of using caterpillars to reduce seeding and suggested other methods of eradicating it include digging the plants up, burning the remains or chemical spraying.

A tool known as a rag fork can help with digging and the British Horse Society also suggests putting salt in the holes left when the plant is extracted to kill off root traces but workers handling ragwort must wear gloves to protect themselves as the plant is also poisonous to humans.

Tim Kohler, Conservation Officer for English Nature Yorkshire and Humberside, said: "Most land occupiers keep their own area clear of the weed.

"However, sometimes the seeds blow over from nearby land and verges, and this needs dealing with using any method which works."

Former Olympic showjumper Harvey Smith, of High Eldwick, whose wife Sue trains racehorses, said: "Ragwort is not a problem I've ever had but it is coming from the road sides. The hedges are not trimmed any more so it blows into grazing fields."

Bradford Council's Countryside and Rights of Way Manager, Danny Jackson, said: "When ragwort is found on Council-owned land our policy is to have it removed as soon as possible."

The British Horse Society has appealed to anyone who has had a horse or pony with ragwort poisoning to contact it in confidence on 08701 20 88 80.