The adults of this species have been observed from mid January to April with the female being flightless.

This species was first described by Edward Meyrick in 1905 using a specimen collected by J. H. Lewis in Ida Valley, Otago.

[8] The type specimen is held at the Natural History Museum, London.

Fore-wings very elongate, narrow, gradually dilated, costa gently arched, apex somewhat acute, termen rounded, rather strongly oblique; fuscous, irregularly irrorated with grey-whitish; a short suffused dark fuscous mark along dorsum towards base; a slender white streak, edged with scattered dark fuscous scales, along fold from base to middle, thence acutely angulated inwards to near dorsum, this portion edged posteriorly with some dark fuscous suffusion; two dark fuscous dots longitudinally placed in disc about 2⁄3; two sub-terminal series of short blackish dashes on veins, and a third less complete on termen : cilia whitish, with two interrupted fuscous lines.

[10] O. sophistes is a dryland specialist[12] and occurs in short tussock grasslands where its host plant is a common component.

[9] This moth is classified under the New Zealand Threat Classification system as being Nationally Vulnerable.