The
bird-cherry ermine (
Yponomeuta evonymella) is a species of moth in the family
Yponomeutidae, native to Europe and parts of Asia. The caterpillars are gregarious and feed on the leaves of the
bird cherry tree, forming silken webbing for their own protection. They create further webbing on the trunk and near the base of the tree, which hides them as they
pupate. This photograph shows one of many bird-cherry ermine caterpillar nests on a tree in
Lahemaa National Park, Estonia. In some years, they are so numerous that they can completely strip a tree of its foliage.
Photograph credit: Charles J. Sharp