Small heath butterflies are not normally seen after September

Butterfly Conservation Scotland (BCS) said it was delighted by the decision, which it hoped would raise the profile of threatened species.

BCS said the announcement came as a small heath butterfly was spotted a month later than usual.

While warmer weather has brought new species to Scotland, several resident ones have declined, the group said.

BCS director Paul Kirkland spotted the small heath butterfly in Stirling. It is not normally seen after September.

Mr Kirkland said climate change had been affecting the insects over a number of years and welcomed their use as a "biodiversity indicator".

He said: "This is recognition butterflies are useful indicators of the state of the environment."

Dr Martin Warren, chief executive of Butterfly Conservation, said the small heath was not an isolated occurrence.

FLUTTER OF TINY WINGS A comma, a butterfly from the south of Britain, was spotted in Dundee in August There are 33 species of butterfly that regularly breed in Scotland and about 1,300 species of moths Several species survive only in Scotland, having died out in England, including the chequered skipper butterfly, Kentish glory moth and New Forest burnet moth Otter and birds on indicators list

He said: "This is a phenomenon we are noticing with a lot of butterflies.

"They are coming out earlier than normal and fitting in extra generations in a year."

Dr Warren added: "The change going on has seen new species colonising Scotland in the last few years.

"Your are getting these lovely butterflies, such as the comma, in your garden and also peacock spreading right across the country."

However, he said other species had suffered from a loss of habitat as a result of weather-related and human activities.

The dingy skipper has declined by 75% in the past 20 years.

One factor in its reduction has been the lack of livestock grazing on coastal grasslands.

Welcoming the government's decision, he said: "It is brilliant news.