I. toroneura is found in the centre of southern South Island in the tussock grasslands of Central Otago and the Mackenzie Basin.

[4] In 2019 Robert Hoare undertook a major review of New Zealand Noctuidae species.

Forewings with costa almost straight, apex obtuse, termen rather obliquely rounded; light brownish-ochreous; veins marked with more or less distinct slender blackish streaks, especially median and subdorsal : cilia pale brownish-ochreous.

[2] This species is endemic to New Zealand and is found in the central parts of southern South Island.

[5][2] This species inhabits the dry inland tussock grasslands of Central Otago and the Mackenzie Basin.

[2] Larvae of this species have been recorded as feeding on tussock grasses Poa cita and Festuca novae-zelandiae.