[1] It is endemic to New Zealand and is found only in the South Island, mainly on the eastern side although not in the Nelson district.

This species was described by Edward Meyrick in 1887 from a male specimen collected at Castle Hill by John Davies Enys and named Leucania acontistis.

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

Head, palpi, antennae, thorax, abdomen, and legs whitish-ochreous, slightly brownish tinged; antennae with strong triangular transverse dentations, terminating in tufts of cilia; collar with an imperfect blackish transverse line.

Forewings moderately dilated, costa hardly arched, apex obtuse, hindmargin rather oblique, rounded beneath; whitish-ochreous, brownish-tinged; a slender attenuated black streak below middle from base to 2⁄5 : cilia ochreous-whitish.

[4] I. acontistis also lacks the discal spot found on the underside of the hindwing which is present in specimens of I.

[4] Larvae feed on tussock grassland species within the genera Poa, Elymus and Rytidosperma.