New atlas catalogues UK's large moth species

Volunteers compile huge database which locates 11.3m individual moth records and shows species decline

Martin Wainwright
guardian.co.uk, Friday 14 January 2011 18.06 GMT

The silent and subtly beautiful visitors which grace Britain's gardens after dark have for the first time been monitored on a massive – and scientifically significant – scale.

Despised and even feared by some, the country's remarkable range of larger moths is catalogued in a new atlas made up of 11.3m individual records.

Hunched over light traps, beating bushes for caterpillars or painting a mix of rum and treacle on tree trunks, volunteers have compiled the enormous database. Their quarry ranges from the noble-sounding splendid brocade and slender burnished brass – both clinging on at a handful of sites in southern England – to moths which drew the short straw for their names, such as the lead-coloured drab and sloe pug.

Based on records from thousands of 10x10km squares across the country, including traps at the Houses of Parliament and Buckingham Palace, the atlas charts a familiar story of species decline. But while there are serious threats to once-familiar moths such as the lappet, which combines a curious snout with the camouflage colour and shape of a dead leaf, others are proving an unexpected success.

Since 1900, some 540 new species have been added to the official British list of larger moths, which is approaching 3,000-strong. Mark Parsons of Butterfly Conservation estimates that 112 are sufficiently well-established to be considered permanent settlers, compared with 62 passing into extinction.

Recorders contributing to the atlas describe as "truly astonishing" the pace of colonisation by newcomers such as the Jersey mocha, dusky peacock and sombre brocade. But changes in climate and the landscape, which largely dictate the health or otherwise of moth populations, have been less kind to the bordered gothic and Brighton wainscot. Both are now officially considered lost.

Moths are important indicators of the welfare of wildlife generally, sensitive to atmospherics and with their caterpillars central to bird diet in the country's food chain. Richard Fox, surveys manager for Butterfly Conservation, said: "Moths have a lot to tell us. Their declines alert us to deterioration in the environment. Where they are found can also tell us something significant about climate change.

"This is why the new atlas is so important. It is a huge step forward in helping to protect Britain's moths. It's been a fantastic effort to get to this stage, with thousands of volunteer moth recorders sending in sightings from every county across the UK."

The data, described as "provisional" because of major analysis and further records yet to come, also shows a steady migration of many species northwards across the UK. Scientists are provisionally linking this to the warming effects of climate change, but remain tentative about definite conclusions.

They also hope that the atlas will increase the number of moth enthusiasts, whose ranks have grown at an unprecedented rate since the invention of digital photography. Far from dull and drab, the insects boast an extraordinary range of colours, including light-reflective metallic wing scales. Camouflage resembles everything from an owl to a fox and Winter moths – currently visible, weakly fluttering in car headlights – survive through a natural anti-freeze in their blood.

Only two species damage fabrics and only one – the flame shoulder – has a genuine reputation for seeking out the warmth and shelter of the human ear. Moths are also one of the UK's relatively few "unknowns" where fresh discoveries can be made; a Dr Blair on the Isle of Wight has three new species to his credit, and all are named after him.

http://www.guardian.co.uk/environment/2011/jan/14/insects-wildlife