The number of butterflies in England has dropped by 30% in the last decade, according to a new study.

Biodiversity Minister Jim Knight said that the study, carried out for Defra by Butterfly Conservation, highlighted the problems faced by butterflies in England. He said: "Butterflies are an iconic species in their own right and they can be good indicators of the health of the entire ecosystem, so this decline is worrying.

"The implications for other insects, birds and mammals are concerning."

The study calculated trends for 40 butterfly species across 820 sites, of which 371 were in agri-environment schemes.

The study also identified that butterflies declined at specific sites for a variety of reasons, including a lack of understanding of habitat requirements by land managers, overgrazing by rabbits, inappropriate bracken or scrub cutting regimes and over and under-grazing.

Mr Knight said that there were some encouraging signs that agri-environment schemes were starting to have an effect on butterfly population decline. He said: "These highly targeted agri-environment schemes may have been playing a positive role to significantly slow and even reverse the declines of these very threatened species, but there is still much work to be done to extend this trend to other butterfly species.

We hope this can be advanced as more and more land comes under the new Environmental Stewardship scheme, which contains management options that should help butterflies.

"Environmental Stewardship, especially the Higher Level Scheme, has the potential to address many of the concerns highlighted in this report and could make a big difference to butterflies and to all the other insects, mammals and birds that rely on them," said Mr Knight.

Dr Tom Brereton, who spearheaded the research for Butterfly Conservation, said: "The results of the survey are worrying, but we are optimistic about the new scheme. Real progress has been made in understanding butterfly declines and what to do about them."

(KMcA/GB)