Birch Bent-wing

Bucculatrix demaryella, or the birch bent-wing, is a moth of the family Bucculatricidae. The species was first described by Philogène Auguste Joseph Duponchel in 1840. It is found in most of Europe (except the Iberian Peninsula and parts of the Balkan Peninsula), Russia and Japan (Hokkaido, Honshu).

The wingspan is 8–9 millimetres (0.31–0.35 in). The head is whitish, mixed in middle with dark fuscous. Forewings are brownish-whitish, irrorated with dark fuscous; two pairs of oblique whitish costal and dorsal streaks before middle and at 3/4, intermediate space dark fuscous towards costa. Hindwings are grey. The larva is dull green, more whitish laterally, the spots white and the head brown.