THE coldest spring in 50 years decimated Lancashire’s butterfly population, wildlife experts said.

Staff at the Lancashire Wildfowl and Wetlands Trust and Butterfly Conservation said that they had seen a reduction of more than 50 per cent in species across East Lancashire.

They said that a combination of extended cold frosts and a mild winter last year meant caterpillar larvae fell victim to unliveable temperatures and made them vulnerable to bird attacks.

Their message came as naturalist Sir David Attenborough issued a national warning that UK butterfly numbers are at a historic low this summer.

Butterflies act as an intrinsic part of the ecosystem with an important place in the food chain, helping to pollinate crops and acting as natural pest control.

Tom Clare, assistant reserve manager at Martin Mere Wetland Centre in Burscough, the county’s main butterfly conservation area, records the number of butterflies at the site each week.

He said: “I’ve not seen a worse year since we began recording around 15 years ago.

“Some species have been harder hit than others because they are more sensitive to weather conditions such as the gatekeeper and common blue.”

He hoped the warmer weather would go some way to counteracting the sudden decline.

“Members of the public can help encourage populations by planting butterfly friendly plants such as buddleias,” he said.

The latest figures come as part of a more long-standing decline in species which has seen a particularly large fall in the past five years.

Laura Sivell, head butterfly recorder for the county and the regional Butterfly Conservation Trust said the biggest reductions had taken place in species not found in East Lancashire.

“I’ve noticed a negative difference this year already because I’ve not seen a butterfly in my garden for several weeks. This is due to a mixture of inclement weather and intensive and planting crops not common to Britain that are unsuitable for butterflies.”

SPECIES NUMBERS FALLING

  • Although there are around 59 native species of butterflies, more than 100 were recorded in the UK earlier this century, with 27 believed to have colonised Britain since 2000.
  • 72 per cent of species decreased in abundance between 2001 and 2011.
  • Specialist species such as the High Brown Fritillary, Duke of Burgundy, Pearl-bordered Fritillary have seen drops of up to 98 per cent in some areas of the country since the 1960s.
  • A minority of wider countryside species have spread northwards, almost certainly in response to climate change such as the Peacock, Comma, Speckled Wood.