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Unmistakeable, the forewing is white with the outer third suffused with orange brown markings encompassing several white triangles and mixed with silver markings. Several brown spots are present in the basal two-thirds of the wing. A long curved scale tuft extends from the middle of the outer margin where the fringe is a three-tiered series of white scales with black tips. The forewing is four to eight millimetres in length, though normally closer to eight. The mature larva is thirteen millimetres in length and yellowish white. It is distinctly segmented and the head is mottled with reddish brown (Dickerson & Weiss, 1920).

Hibernates as a larva inside the stem in cells where it can easily be found in the winter (Forbes 1923). In a primrose stem they tend to be in the lower portions of the main shoot or occasionally in the side shoots and there may be anywhere from one or two to thirty or more in one plant. During April and May the larva spins a cocoon in the cell and pupates inside it in late May to mid June. Eggs are laid on leaves and probably stems, and larvae start to bore in the stems, making longitudinal cavities under the bark and between the pith and bark. There are many reared parasitoids of this species including six Hymenoptera and one mite (Dickerson & Weiss 1920).