Rare butterflies are making a comeback at the Royal Botanic Gardens at Kew. Staff have introduced conservation techniques that mean the west London gardens have become more attractive to butterflies than many rural areas.

Varieties of butterfly have been enticed back by phased grass mowing and the planting of selected trees.

Sandra Bell, co-ordinator of the butterfly management scheme, said: 'It's wonderful that we can sustain larger populations by sympathetic management.'

One of the biggest success stories is that of the White Letter Hair Streak, a rare species of English butterfly, which is being attracted back to Kew by an exotic Asian variety of the elm. It will only lay eggs on the twigs of a flowering, mature elm in bright sunlight and it virtually disappeared during the outbreak of Dutch Elm Disease in the 1970s.

Staff have reported that their latest survey found almost 100 in the grounds. Sightings for all butterflies have increased considerably compared with previous years.

Other species that are flourishing are the Holly Blue, Speckled Wood, Small Tortoise Shell, Peacock, Brimstone and the Meadow Brown Ms Bell said the conscious effort being made not only at Kew but also in other green areas of London would result in a rise in the number of butterflies across the whole city.

Ironically, cities can often provide more suitable natural habitats than rural areas as the extensive use of chemical fertilisers and pesticides in the countryside has made life difficult for all types of wildlife in the hedgerows.

(Photograph omitted)