Wingspan 14–18 mm.
This moth is rather conspicuous by its large size en golden-yellow colour. It has also a few white lines.
The antennae are alternately ringed brownish white till the tip.

The larva makes small mines to build the case, or it lives in a seed pod.

The caterpillar builts a two-valved tubular case, the mouth angle is about 45°.
See also bladmineerders.be.

The caterpillar feeds on the seeds. In the past there was a lot of confusion with Coleophora oriolella Zeller, 1849, therefore it is still a discussion about what exactly the food plants are…
Notes from Dr. W. Ellis in Parasites of Europe: “In the literature before the publication by Patzak (1974a) mostly it is stated incorrectly that the larva would live in a lobe case. In any case, the illustrations and descriptions by Hering (1957a), Toll (1962a), and Razowski (1990a) do not relate to C. coronillae; it is conceivable that they actually refer to C. oriolella. Faunistical and biological information about coronillae should be treated cautionary, therefore. In particular, it remains to be seen if the species lives on other host plants than Securigera (Coronilla). Baldizzone (2004a) describes the case as lightly colored; the larva should live on the pods.

The larvae feeds on Securigera (Coronilla) varia. Possible but not at all sure also on Astragalus glycyphyllos and Lathyrus.