Lichens are lowly plants that look most unappetising and unnourishing - not at all like the juicy leaves that caterpillars usually like!

Lichens are lowly plants that are made of an alga and a fungus living together symbiotically – they are commonly seen on trees, roofs, gravestones and other rocks, and tend to grow only where the air is unpolluted.

The lichen feeding moths include the small highly patterned and beautifully camouflaged Marbled Green, Marbled Beauty, Marbled Grey, the Brussels Lace.

The very pretty Rosy Footman and many other members of the Footman family have larvae that feed on lichens. These are also becoming increasingly common.

Lichens were seriously affected by the air pollution caused by the industrial developments of the 19^th and 20^th centuries and as a result these moths became very scarce.

Now that our air is much cleaner than it used to be, Lichen-feeding moths are becoming commoner. This is quite a contrast with the majority of other moth species that are declining over much of the UK (**)

One uncommon species, the very attractive Tree Lichen Beauty, was found in 2007 in a moth trap set on the Houses of Parliament in central London.

**Click here to see details of the latest report into 'The State of Britain's Moths'.