[1] It is endemic to New Zealand and found only in the middle and lower parts of the North Island.

This species was described and illustrated by George Hudson in 1898 and named Melanchra omicron.

[3] The type specimen is missing and has not been found at Museum of New Zealand Te Papa Tongarewa.

[2] In 1928 Hudson, thinking M. omicron was the same species as Aletia inconstans, discussed it under the latter name in his book The Butterflies and Moths of New Zealand.

The fore-wings are pale olive-green, mottled and striped with dull grey; there is a double transverse line near the base, another at about one-fourth, and another at about one-half, passing between the orbicular and the reniform; beyond this, there are two indistinct shaded lines, and a terminal series of black marks; the orbicular is large, almost circular, and sharply outlined in black; the claviform is small and indistinct, and the reniform ill-defined, obscurely outlined in black towards the base.

[2] This species has been classified as having the "At Risk, Naturally Uncommon" conservation status under the New Zealand Threat Classification System.