The host species of this moth is unconfirmed but it has been hypothesised that it is likely Rytidosperma pulchrum as females of the species have been discovered at the base of this plant. O. jansoni is known to inhabit roadside grasslands along the Desert Road north of Waiouru, and has also been collected at the Rangitaiki Frost Flats. It is likely that it also inhabits New Zealand Defence Force land around Waiouru. It prefers open grassland habitat.