TV garden shows could be to blame for a massive drop in butterfly numbers.

Luke Brown, manager of Studley Grange Butterfly World in Wroughton, claims programmes such as Ground Force are giving rise to "designer gardens" with more emphasis on neat borders than butterfly-friendly flowerbeds.

Mr Brown's comments come in the wake of a report published in Science magazine.

Volunteer checkers found that the butterfly population had dropped 71 per cent in the past 40 years.

And Mr Brown warned that unless people began to introduce more butterfly-friendly flora into their gardens, the sight of a Cabbage White could soon become a thing of the past.

"There has certainly been a noticeable drop in butterflies even in the past 10 or 15 years, with some species now extinct," he said.

"My grandmother would have seen the Large Blue butterfly.

"This particular species died out 50 years ago.

"There are now schemes to introduce them at a secret location within an hour's drive of Swindon."

Mr Brown is adamant that the recent explosion in the popularity of gardening shows is posing a real threat to the colourful insects.

He said: "The programmes are having a significant effect.

"While it's good to see people taking a greater interest in gardening, it seems they are overlooking what butterflies really need nettles, thistles and grasses.

"Flowers are important for the butterflies but the caterpillars feed on nettles. A lot of gardeners do not realise that.

"While butterflies themselves do not form a major part in the food chain they are a good indicator of the general decline in insects. Without them, bird numbers would drop."

And he said that crop spraying and pesticides were also posing a serious threat.

Insects currently make up more than half of the planet's species.

At Studley Grange Butterfly World, staff are working flat-out to plant almost 3,000 wild plants in gardens behind the huge greenhouse to encourage Britain's native butterfly species.

Currently the glasshouse, which is kept at a constant 85 degrees Fahrenheit, boasts between 700 and 1,000 tropical butterflies.

Species include the Blue Morpho, which originates from South America and the Tree Nymph from South Asia.

Mr Brown said: "We like to practise what we preach.

"We hope to open the new section to the public soon."

Kevin Shoesmith