Lepidoptera

The Nepticulidae are highly specialized moths and include the smallest known moths in the world.  Almost all of their larvae mine the leaves of trees or herbaceous plants and in many cases it is easier to identify the species from the pattern and shape of the mine left behind by the larva than it is to identify the adults, most of which require microscopic examination of the dissected genetalia for confident identification.  In Britain, about 100 species are known to occur.

Stigmella perpygmaeella / Stigmella incognitella