Wingspan 11.5-14.5 mm.
Nationally Scarce B
Due to confusion with C. alcyonipennella the distribution of this species is not well known. Imagines are not separable with certainty using external features so identification of likely specimens should be by dissection.
In common with its close relative it inhabits grassy areas where the food plant, clover (Trifolium sp.), is abundant. The larvae feed on the seeds from within a cryptic case.
There are some indications that this species might be univoltine in contrast to alcyonipennella so it is particularly worth checking imagines found in May and June.