Families across the region are being urged to play their part in addressing a long-term decline in butterfly numbers.

A new survey by wildlife charity Butterfly Conservation and the Centre for Ecology and Hydrology reports that 72pc of species have suffered declines in the past 10 years.

More than half of UK butterflies have seen their distribution across the country reduced, the study shows.

Regional Butterfly Conservation recorder Andy Brazil said Norfolk mirrored the general national decline, but said there had been some notable success stories as well.

He said: 'One really doing badly is the peacock which suffered a catastrophic decline in 2010 and has not really recovered.

'It has only happened on the East coast and Norfolk has been the worst hit, which suggests a new parasite coming over from the continent.

'That is what happened to the small tortoiseshell in 2008 when a new parasite began laying eggs on the caterpillars. At the worst point 40pc of caterpillars were affected, but numbers have begun to recover again.'

Mr Brazil said the swallowtail butterfly – only found on nature reserves in the Broads including the Butterfly Conservation reserve at Catfield Fen – was doing fine generally, although the hot spring had affected numbers.

'The butterflies were emerging early when their food source, milk parsley, was not tall enough to find between the reeds,' he said.

One butterfly bucking the national trend of decline and doing well in Norfolk was the woodland butterfly, the white admiral.

'Another ray of good news is the silver-washed fritillary which has come back to Norfolk, having been seen for the first time in two decades last year,' he said.

Norfolk's top 10 butterflies in a survey carried out last year saw the large white top the list followed by the small white, meadow brown, gatekeeper, green veined white, red admiral, small tortoiseshell, speckled wood, peacock and comma. The big mover was the peacock which had been number three in the Norfolk rankings in 2007.

The decline in butterflies is reflected in the fact Norfolk has 35 breeding species, down from 45 known to have bred in the past.

Mr Brazil said families could help by making their gardens wildlife havens. Butterflies were attracted to nectar plants such as bluebell, clover, daisy, dandelion, forget-me-not, pansy and wallflower in the spring and buddleia, french marigold, lavendar, marjoram, mint, red valerian and thyme in the late summer and autumn.

He also urged people to leave patches of nettles and weeds.