Adults are on the wing in January and have been collected just before sunrise at the bushline in native Nothofagus forest.

This species was first described by Charles Edwin Clarke in 1934 using one specimen collected at the bushline at Harris Saddle, upper Routeburn River, in January.

[3][2] George Hudson discussed this species in his 1939 book A supplement to the butterflies and moths of New Zealand.

[4] However J. S. Dugdale recognised M. cataclysma as a separate species in his 1988 annotated catalogue of New Zealand lepidopteria.

Forewings elongate, costa arched, apex acutely rounded, termen oblique; very pale ochreous with fuscous markings and irroration, the most distinct at about ½ on costa, others at ⅔ broken and irrorated, distinct on dorsum; others across from near edge of termen.