ENVIRONMENTAL campaigners are calling for help from the public to halt the decline of a rare species of bee.

The wall mason, a stone-dwelling pollinator, is highly dependent on the pollen of the wildflower bird’s-foot trefoil, which it needs to feed its young.

As a result of intensified farming and urban development, the plant has declined, and this is believed to have had a bad impact upon the wall mason population.

Bob Fulton, a beekeeper from Darwen, said there was also a problem of people mistaking the bee for other insects.

He said: “People panic when they see a mason bee in a crack in their house, because they think it might damage it like a wasps’ nest.

“But masons will just take a bit of a leaf and feed their young in there.

They don’t swarm or attack the building or people, so you shouldn’t harm them.”

It comes as a new report by the University of Reading reveals the north west as having the last remaining population of the wall mason species.

Numbers of the 250 types of bees in Britain have fallen in recent years, affected by disease, pesticides and habitat loss.

A spokesman for the Lancashire Wildlife Trust said there were many ways people can help the species to grow once again.

He said: “Planting flowers which the bees feed on will help them.

“Using less chemicals in your garden, such as ones to kill greenfly, will also help.

“Learning the different types of bee and letting us and other wildlife groups know what there is in your garden will help us keep a record of numbers so we know which ones are struggling.

“If we get to the point where there are no bees left, then we’re going to be in a very desperate situation.”

A study last year showed it would cost farmers £1.8bn a year to replace the pollination service bees provide for free. Britain has lost 20 species of bee since 1900.