Cosmia pyralina, the lunar-spotted pinion, is a moth of the family Noctuidae.

Forewing dull or bright redbrown on a pinker ground; generally darkened with olive fuscous; first line blackish, oblique, not white-edged, angled outwards between and inwards on the veins; outer line preceded by a darker median shade, and edged with white, the white becoming diffused on costa and joined to the white streak before the submarginal line; stigmata very obscure, sometimes with dark centres on a paler ground; submarginal line preceded by a darker red shade; wing pale grey in the male, darker in the female; the brighter coloured forms are ab.

Larva pale green with white lines; spiracular line yellowish, black edged above; head yellow green.

[3] This moth is rather similar Cosmia affinis, but it shows paler hindwings and broader forewings.

The larvae feed on various deciduous trees, including Ulmus,[3] Pyrus, Salix and Quercus living between united leaves, spinning a slight silken web in which to pupate.