This species was first described in 1883 by Edward Meyrick using material collected by him at Arthur's Pass and Mount Hutt and named Pasithea mechanitis.

Forewings moderate, hind margin rounded; dark fuscous, densely irrorated and median band almost wholly suffused with yellow; a nearly straight yellow or whitish line towards base, anteriorly strongly blackish-margined; an irregularly curved white line at 1⁄3, posteriorly strongly blackish-margined; a small blackish discal dot; an irregularly angulated slender dark fuscous median line, beyond which is another almost confluent with next line; a white line beyond middle, anteriorly strongly blackish-margined, strongly angulated in middle, subdentate beneath; a slender very sharply dentate irregular yellow subterminal line; cilia with basal half dark grey, apical half wholly white.

[3][7][11] The female moth lays her eggs within the flower buds of their host plant.

[12] When the larvae emerge from their eggs, they eat into the leaves or buds of their host, hiding from predators.

[3] This moth species prefers to live in grassy high alpine habitat.