Britain to build world's biggest butterfly house

Britain is to build the world's biggest butterfly house as a giant visitor attraction with a giant conservation message: stop butterflies disappearing.

Butterfly World, which will have 10,000 butterflies at a time fluttering under its 300ft-wide, walk-through dome, is being built just off the M25, near St Albans, Hertfordshire. The £25m project was launched yesterday with the support of some of the major voices in Britain's conservation community, led by Sir David Attenborough.

Sir David said that three quarters of British butterflies had declined in the past 20 years, some of them very rapidly. "These declines indicate an underlying deterioration of the environment as a whole," he said. "For the sake of future generations we must take action now. Butterfly World is doing just that. It is putting the issues on the agenda and is seeking to help reverse this environmental catastrophe."

The project is the brainchild of the businessman/ environmentalist Clive Farrell, a passionate lepidopterist (enthusiast for butterflies and moths) who has already opened butterfly houses in Florida, Switzerland and Stratford-upon-Avon.

Butterfly World is planned to open in stages between June 2009 and March 2011. When finished, it will have 10,000 tropical butterflies of 250 species on free-flying view under its dome at any one time, in the world's largest such display, in addition to extensive gardens and meadows to attract native British species, as well as education and research facilities.

If it successful in attracting its target of a million visitors a year – 40 per cent of them expected to be children– it will rival the Eden Project in Cornwall for the title of Britain's premier environmental tourist attraction.

"Butterflies are like the canaries in the coal mine," Mr Farrell said yesterday. "When their environment is under stress, they are the first to suffer and disappear. During the 20th century, five of Britain's butterfly species and 60 moth species became extinct.

"Drastic butterfly losses are continually being reported as we destroy their natural habitats at a frightening pace, and Butterfly World is designed to bring the public into direct contact with some of the most fragile and beautiful wildlife in the world and send out a clarion call on behalf of this endangered treasure."

Trustees of the project who attended the launch included the botanist David Bellamy and Jeremy Thomas, professor of ecology at the University of Oxford and Britain's leading butterfly expert.

Professor Bellamy said: "Every kid in the world has butterflies living near them, and from this starting point we make kids think about what's happening on a world scale," .

Professor Thomas, the man responsible for bringing the large blue butterfly back from extinction in Britain, after having worked out vital aspects of its unique lifestyle – the caterpillar is taken into an ant's nest to be reared by the ants – added: "What is bad for butterflies is bad for all species – including our own.

"Globally, the loss of countless species of animals and plants will be catastrophic for mankind, not least because of the loss of potential benefits such diversity can bring to many disciplines, including medical research."

Species that became extinct

Mazarine blue (Polyommatus semiargus)

This small, pretty butterfly, found across Europe, feeds on red clover. The last colony in Britain died out in 1904.

Black-veined white (Aporia crataegi)

Still common in Europe, this relative of the large and small whites has been extinct in the UK since 1925, perhaps because of agricultural chemical use.

Large tortoiseshell (Nymphalis polychloros)

Common in southern England until after the war, it became extinct after Dutch elm disease destroyed its main food source.

Large blue (Maculinea arion)

Extinct since 1979, the large blue has been reintroduced after scientists discovered its unique habitat – its caterpillars live in ants' nests.