This species has only been observed in the Humboldt Ranges of Otago and inhabits subalpine native bush at elevations of around 3600 ft.

This species was first described by Edward Meyrick in 1907, using a specimen collected by George Hudson at the Humboldt Range, Lake Wakatipu at 3,600 ft, and named Simaethis exocha.

[3] In 1928 George Hudson discussed and illustrated this species under that name in his book The butterflies and moths of New Zealand.

[2] The male holotype specimen, collected in the Humboldt Mountains, is held at the Natural History Museum, London.

Fore-wings elongate, moderate, posteriorly rather dilated, costa gently arched, apex obtuse, termen faintly sinuate, oblique; 7 and 8 connate; olive-fuscous, costa and dorsum broadly suffused with dark fuscous; basal area irrorated with whitish except a narrow fascia preceding first line; first line whitish, acutely angulated near costa, followed by a very irregular fascia of whitish irroration, which sends a triangular projection above middle to centre of disc; second line white, sharply defined, running from middle of costa to 3⁄4 of disc, thence acutely angulated to beyond middle of dorsum, somewhat sinuate inwards towards costa and dorsum; an evenly broad fascia of white irroration from 4⁄5 of costa to 4⁄5 of dorsum, resting on second line in discal portion, terminating in a white spot on costa, and edged with a white line from this to angle of second line: cilia grey mixed with whitish, and indistinctly barred with dark fuscous irroration.