Moth numbers down, but some have moved to area

Pale Pinion Garden Tiger Moth
Pale Pinion Garden Tiger Moth

LATEST research says three of the UK’s larger moths have become extinct in the last decade.

Work by the Butterfly Conservation and Rothamsted Research shows two thirds of common larger species have declined in the last 40 years.

V-Moth

V-Moth

And their ‘The State of Britain’s Larger Moths 2013’ report, out earlier this month, finds that nationally the garden species V-moths, Garden Tigers and Spinaches decreased by more than 90 per cent between 1968 and 2007.

It also found that over a third (37 per cent) of the bigger moths have declined by at least half.

But the story further north is different, says Butterfly Conservation East Scotland’s organiser Barry Prater.

He said: “The total abundance of moths in the northern half of Britain has shown no overall change over the past 40 years, with declines in some moth species being balanced out by other moths doing well.”

Garden Tiger Moth.

Garden Tiger Moth.

Examples of moths doing well more locally would be the Autumnal Rustic (despite 94 per cent decline nationally), Green-brindled Crescent (81 per cent decline) and the fabulous Garden Tiger (92 per cent decline) “which is common all over our area and frequently met with as ‘woolly bear’ caterpillars” (pictured top of page).

But he admitted: “Some of the more dramatic losses of moths highlighted in this report have been experienced here in the Borders. We, too, have all but lost the appropriately-named V-Moth – whose caterpillars feed on gooseberry and currant bushes – could it be that these fruits have gone out of fashion or is it perhaps the widespread use of insecticide sprays which has caused the decline?”

Climate change – combined in some cases with greater habitat loss – has meant some moths previously found only in south England have now colonised parts of Scotland.

“Perhaps the most dramatic example is the Pale Pinion, which up to 1980 only occurred south-west of a line from the Thames to the Mersey, but can now be found north of Edinburgh and is generally widespread across the Borders,” said Mr Prater.

“It’s a similar distribution-change story with Blair’s Shoulder-knot, a moth first recorded in Britain in 1951 on the Isle of Wight and now to be found as far north as Fife. This moth’s caterpillars feed on conifers, including the infamous leylandii beloved (or hated) by many gardeners, and so once in the country would have had no difficulty finding suitable places to breed and for its offspring to thrive.”

Ongoing habitat loss and the deteriorating condition of the countryside are blamed for the majority of the losses.

“The declines of many moths across Britain are worrying and are often apparent here in Scotland, although they may not be as serious as further south – not yet, that is, so there is no cause to be smug about our somewhat better (or less worse) situation, “ said Mr Prater.

“The spread and increase of some species is interesting and research into the causes may help us understand the ecology of this large group of animals and so pave the way to their effective conservation.”

Moths are important indicators of the quality of the environment and changes in moth numbers and where they rae found reflect changes in climate, land use and “how we look after our world”, said Mr Prater.

“Fewer moths and a drop in diversity amongst them are bad signs, whereas more moths and a growing variety are encouraging signs,” he added.

“Moths are important pollinators of plants and so contribute to our needs; as flying insects they are a foodsource for our bats and birds and many birds and lower forms of life will feed on caterpillars or chrysalises. They truly illustrate well how fully they are a part of the ‘web of life’ which is biodiversity.”

For more information on the local group and on volunteering for survey work, visit http://eastscotland-butterflies.org.uk/index.html