They vary both in colour, from reddish brown to a greenish yellow shade, and also in the extent of the black marking on their forewings.

This species was first described by Francis Walker using specimens collected in Nelson by T. R. Oxley and named Cryptolechia coarctatella.

[5] George Hudson discussed and illustrated this species in his 1928 book The butterflies and moths of New Zealand under the name Cryptolechia liochroa.

coarctatella has a wingspan of between 22 and 30 mm and is variable in appearance with some specimens having a greenish shade to their forewings and others being a reddish brown colour.

[7] Hudson states that when they are in this position they closely resemble a dead leaf and that this imitation provides the moth with some protection from predators.

[6] They shelter in hollow twigs, under bark or old wood-borer tunnels during the day and emerge to feed on epiphytic lichens during the evening.