Eriocrania unimaculella

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Eriocrania unimaculella, the White-spot Purple, is a tiny European moth in the family Eriocraniidae. It was first described in 1839 by Swedish naturalist Johan Wilhelm Zetterstedt. The wingspan is about 1 centimeter. The forewings are bronzy-purple with a narrow white spot near the middle of the wing; the hindwings are gray with a purple tinge. Adults fly from March to April and this species lacks the gold mottling seen in some relatives.

Eggs are laid in the leaf buds of birch trees (Betula species). The larvae feed inside birch leaves, creating a large white blotch mine that withers the leaf by late summer. The larva is whitish with a brown head and overwinters as a pupa in a tough silken cocoon in the soil.

Distribution covers much of Europe—from Great Britain, Ireland, and France north to Scandinavia and east to Russia. It has been spreading in Iceland since around 2005.

Taxonomy notes: the species was originally named Adela unimaculella and has been placed in different genera in the past. The name unimaculella refers to the single white spot on the forewing.