Yarrow Case-bearer

The wingspan is 9.5–13 mm. The forewing is cream-coloured with distinct white longitudinal stripes and with oblique streaks and scattered fuscous scales. Certain identification requires examination of genitalia preparations. Adults are on wing in June and July.

Ovum Eggs are laid on the flowers of yarrow (Achillea millefolium) and sneezewort (Achillea ptarmica).

Larva The early instars feed from early September on the withering flowers and seeds.

Pupa Pupation takes place within the case.

The genus Coleophora was raised by the German entomologist Jacob Hübner in 1822. The name refers to a sheath, i.e. to carry, from the portable case the larvae make. The moth was named argentula by the English entomologist James Francis Stephens in 1834, from a specimen found near London, England. The species name comes from argentum – the silver streaks along the veins on the forewing, which are in contrast to the ochreous ground colour.