The backing of Assembly Members is the first step forward in a number of future initiatives to look at sustainable development in Wales, which is one of the most difficult briefs of the Assembly.

Four rare species of moth and butterfly - Ashworth's rustic, Weaver's wave, rosy marsh moth and the Silurian - are only found in Wales and are the focus of a burgeoning partnership between the Assembly, Countryside Council for Wales and UK pressure group Butterfly Conservation.

Urban sprawl

The insects have been recognised as key indicators in detecting the health of the countryside, as farming practices change and urban sprawl from towns and cities encroaches on green field sites.

Bridgend AM Carwyn Jones said he was delighted to see his own constituency in the forefront of plans to draw attention to the threat facing habitats and species.

Politicians have backed a conservation action plan

"Sustainable development is all about improving the quality of life for people today and in the future," said Mr Jones.

"Development cannot be sustainable if it involves the loss of important species and habitats."

Mr Jones has joined MP Win Griffiths in publicising the action plan initiative, which was launched at Bridgend County Council's offices and will focus on woodlands, mountainsides, grasslands and bogs.

"Sensitive indicators"

Dr Malcolm Smith, senior director and chief scientist for the Countryside Council for Wales, said moths and butterflies were in the front line for detecting environmental changes.

"They are sensitive indicators of the health of our countryside will, in turn, bring about a healthier environment for us all to live in and enjoy," he said.